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Kalita AI, Keller Valsecchi CI. Dosage compensation in non-model insects - progress and perspectives. Trends Genet 2024:S0168-9525(24)00207-5. [PMID: 39341686 DOI: 10.1016/j.tig.2024.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Revised: 08/26/2024] [Accepted: 08/28/2024] [Indexed: 10/01/2024]
Abstract
In many multicellular eukaryotes, heteromorphic sex chromosomes are responsible for determining the sexual characteristics and reproductive functions of individuals. Sex chromosomes can cause a dosage imbalance between sexes, which in some species is re-equilibrated by dosage compensation (DC). Recent genomic advances have extended our understanding of DC mechanisms in insects beyond model organisms such as Drosophila melanogaster. We review current knowledge of insect DC, focusing on its conservation and divergence across orders, the evolutionary dynamics of neo-sex chromosomes, and the diversity of molecular mechanisms. We propose a framework to uncover DC regulators in non-model insects that relies on integrating evolutionary, genomic, and functional approaches. This comprehensive approach will facilitate a deeper understanding of the evolution and essentiality of gene regulatory mechanisms.
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2
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Li X, Mank JE, Ban L. The grasshopper genome reveals long-term gene content conservation of the X Chromosome and temporal variation in X Chromosome evolution. Genome Res 2024; 34:997-1007. [PMID: 39103228 PMCID: PMC11368200 DOI: 10.1101/gr.278794.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 07/02/2024] [Indexed: 08/07/2024]
Abstract
We present the first chromosome-level genome assembly of the grasshopper, Locusta migratoria, one of the largest insect genomes. We use coverage differences between females (XX) and males (X0) to identify the X Chromosome gene content, and find that the X Chromosome shows both complete dosage compensation in somatic tissues and an underrepresentation of testis-expressed genes. X-linked gene content from L. migratoria is highly conserved across seven insect orders, namely Orthoptera, Odonata, Phasmatodea, Hemiptera, Neuroptera, Coleoptera, and Diptera, and the 800 Mb grasshopper X Chromosome is homologous to the fly ancestral X Chromosome despite 400 million years of divergence, suggesting either repeated origin of sex chromosomes with highly similar gene content, or long-term conservation of the X Chromosome. We use this broad conservation of the X Chromosome to test for temporal dynamics to Fast-X evolution, and find evidence of a recent burst evolution for new X-linked genes in contrast to slow evolution of X-conserved genes.
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Affiliation(s)
- Xinghua Li
- Department of Grassland Resources and Ecology, College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
- National Engineering Laboratory for Animal Breeding, Department of Animal Genetics and Breeding, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China
| | - Judith E Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Liping Ban
- Department of Grassland Resources and Ecology, College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China;
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3
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He L, Wang Y, Wang Y, Zhang RG, Wang Y, Hörandl E, Ma T, Mao YF, Mank JE, Ming R. Allopolyploidization from two dioecious ancestors leads to recurrent evolution of sex chromosomes. Nat Commun 2024; 15:6893. [PMID: 39134553 PMCID: PMC11319354 DOI: 10.1038/s41467-024-51158-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 07/31/2024] [Indexed: 08/15/2024] Open
Abstract
Polyploidization presents an unusual challenge for species with sex chromosomes, as it can lead to complex combinations of sex chromosomes that disrupt reproductive development. This is particularly true for allopolyploidization between species with different sex chromosome systems. Here, we assemble haplotype-resolved chromosome-level genomes of a female allotetraploid weeping willow (Salix babylonica) and a male diploid S. dunnii. We show that weeping willow arose from crosses between a female ancestor from the Salix-clade, which has XY sex chromosomes on chromosome 7, and a male ancestor from the Vetrix-clade, which has ancestral XY sex chromosomes on chromosome 15. We find that weeping willow has one pair of sex chromosomes, ZW on chromosome 15, that derived from the ancestral XY sex chromosomes in the male ancestor of the Vetrix-clade. Moreover, the ancestral 7X chromosomes from the female ancestor of the Salix-clade have reverted to autosomal inheritance. Duplicated intact ARR17-like genes on the four homologous chromosomes 19 likely have contributed to the maintenance of dioecy during polyploidization and sex chromosome turnover. Taken together, our results suggest the rapid evolution and reversion of sex chromosomes following allopolyploidization in weeping willow.
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Affiliation(s)
- Li He
- Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China.
| | - Yuàn Wang
- Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Yi Wang
- Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
- Laboratory of Systematic Evolution and Biogeography of Woody Plants, School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, 100083, China
| | - Ren-Gang Zhang
- Yunnan Key Laboratory for Integrative Conservation of Plant Species with Extremely Small Populations, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China
- University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Yuán Wang
- Eastern China Conservation Centre for Wild Endangered Plant Resources, Shanghai Chenshan Botanical Garden, Shanghai, 201602, China
| | - Elvira Hörandl
- Department of Systematics, Biodiversity and Evolution of Plants (with Herbarium), University of Göttingen, Göttingen, Germany
| | - Tao Ma
- Key Laboratory for Bio‑Resource and Eco‑Environment of Ministry of Education & Sichuan Zoige Alpine Wetland Ecosystem National Observation and Research Station, College of Life Science, Sichuan University, Chengdu, China
| | - Yan-Fei Mao
- CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Judith E Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada
| | - Ray Ming
- Centre for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Crops, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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4
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Deng Z, Zhang Y, Xie X, Li H, Guo H, Ni X, Li X. Transcriptomic and proteomic elucidation of Z chromosome dosage compensation in Helicoverpa armigera. INSECT MOLECULAR BIOLOGY 2024. [PMID: 38949741 DOI: 10.1111/imb.12939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 06/17/2024] [Indexed: 07/02/2024]
Abstract
Transcriptomic data have been used to study sex chromosome dosage compensation (SCDC) in approximately 10 Lepidoptera ZW species, yielding a consensus compensation pattern of Z≈ ZZ < AA . $$ \approx \mathrm{ZZ}<\mathrm{AA}. $$ It remains unclear whether this compensation pattern holds when examining more Lepidoptera ZW species and/or using proteomic data to analyse SCDC. Here we combined transcriptomic and proteomic data as well as transcriptional level of six individual Z genes to reveal the SCDC pattern in Helicoverpa armigera, a polyphagous lepidopteran pest of economic importance. Transcriptomic analysis showed that the Z chromosome expression of H. armigera was balanced between male and female but substantially reduced relative to autosome expression, exhibiting an SCDC pattern of Z≈ ZZ < AA $$ \approx \mathrm{ZZ}<\mathrm{AA} $$ . When using H. amigera midgut proteomic data, the SCDC pattern of this species changed from Z≈ ZZ < AA $$ \approx \mathrm{ZZ}<\mathrm{AA} $$ at transcriptomic level to Z = ZZ = AA at the proteomic level. RT-qPCR analysis of transcript abundance of six Z genes found that compensation for each Z gene could vary from no compensation to overcompensation, depending on the individual genes and tissues tested. These results demonstrate for the first time the existence of a translational compensation mechanism, which is operating in addition to a translational mechanism, such as has been reported in other lepidopteran species. And the transcriptional compensation mechanism functions to accomplish Z chromosome dosage balance between the sexes (M = F on the Z chromosome), whereas the translation compensation mechanism operates to achieve dosage compensation between Z chromosome and autosome (Z = AA).
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Affiliation(s)
- Zhongyuan Deng
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yakun Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xingcheng Xie
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huihui Li
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Han Guo
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Xinzhi Ni
- USDA-ARS, Crop Genetics and Breeding Research Unit, University of Georgia-Tifton Campus, Tifton, Georgia, USA
| | - Xianchun Li
- Department of Entomology and BIO5 Institute, University of Arizona, Tucson, Arizona, USA
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5
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Webster TH, Vannan A, Pinto BJ, Denbrock G, Morales M, Dolby GA, Fiddes IT, DeNardo DF, Wilson MA. Lack of Dosage Balance and Incomplete Dosage Compensation in the ZZ/ZW Gila Monster (Heloderma suspectum) Revealed by De Novo Genome Assembly. Genome Biol Evol 2024; 16:evae018. [PMID: 38319079 PMCID: PMC10950046 DOI: 10.1093/gbe/evae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 01/23/2024] [Accepted: 01/23/2024] [Indexed: 02/07/2024] Open
Abstract
Reptiles exhibit a variety of modes of sex determination, including both temperature-dependent and genetic mechanisms. Among those species with genetic sex determination, sex chromosomes of varying heterogamety (XX/XY and ZZ/ZW) have been observed with different degrees of differentiation. Karyotype studies have demonstrated that Gila monsters (Heloderma suspectum) have ZZ/ZW sex determination and this system is likely homologous to the ZZ/ZW system in the Komodo dragon (Varanus komodoensis), but little else is known about their sex chromosomes. Here, we report the assembly and analysis of the Gila monster genome. We generated a de novo draft genome assembly for a male using 10X Genomics technology. We further generated and analyzed short-read whole genome sequencing and whole transcriptome sequencing data for three males and three females. By comparing female and male genomic data, we identified four putative Z chromosome scaffolds. These putative Z chromosome scaffolds are homologous to Z-linked scaffolds identified in the Komodo dragon. Further, by analyzing RNAseq data, we observed evidence of incomplete dosage compensation between the Gila monster Z chromosome and autosomes and a lack of balance in Z-linked expression between the sexes. In particular, we observe lower expression of the Z in females (ZW) than males (ZZ) on a global basis, though we find evidence suggesting local gene-by-gene compensation. This pattern has been observed in most other ZZ/ZW systems studied to date and may represent a general pattern for female heterogamety in vertebrates.
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Affiliation(s)
- Timothy H Webster
- Department of Anthropology, University of Utah, Salt Lake City, UT, USA
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Annika Vannan
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Brendan J Pinto
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA
- Department of Zoology, Milwaukee Public Museum, Milwaukee, WI, USA
| | - Grant Denbrock
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Matheo Morales
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Department of Genetics, Yale University, New Haven, CT, USA
| | - Greer A Dolby
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Dale F DeNardo
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Melissa A Wilson
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA
- Center for Mechanisms of Evolution, Biodesign Institute, Tempe, AZ, USA
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6
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Kimura A, Go AC, Markow T, Ranz JM. Evidence of Nonrandom Patterns of Functional Chromosome Organization in Danaus plexippus. Genome Biol Evol 2024; 16:evae054. [PMID: 38488057 PMCID: PMC10972686 DOI: 10.1093/gbe/evae054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2024] [Indexed: 05/01/2024] Open
Abstract
Our understanding on the interplay between gene functionality and gene arrangement at different chromosome scales relies on a few Diptera and the honeybee, species with quality reference genome assemblies, accurate gene annotations, and abundant transcriptome data. Using recently generated 'omic resources in the monarch butterfly Danaus plexippus, a species with many more and smaller chromosomes relative to Drosophila species and the honeybee, we examined the organization of genes preferentially expressed at broadly defined developmental stages (larva, pupa, adult males, and adult females) at both fine and whole-chromosome scales. We found that developmental stage-regulated genes do not form more clusters, but do form larger clusters, than expected by chance, a pattern consistent across the gene categories examined. Notably, out of the 30 chromosomes in the monarch genome, 12 of them, plus the fraction of the chromosome Z that corresponds to the ancestral Z in other Lepidoptera, were found enriched for developmental stage-regulated genes. These two levels of nonrandom gene organization are not independent as enriched chromosomes for developmental stage-regulated genes tend to harbor disproportionately large clusters of these genes. Further, although paralogous genes were overrepresented in gene clusters, their presence is not enough to explain two-thirds of the documented cases of whole-chromosome enrichment. The composition of the largest clusters often included paralogs from more than one multigene family as well as unrelated single-copy genes. Our results reveal intriguing patterns at the whole-chromosome scale in D. plexippus while shedding light on the interplay between gene expression and chromosome organization beyond Diptera and Hymenoptera.
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Affiliation(s)
- Ashlyn Kimura
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92647, USA
| | - Alwyn C Go
- Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - Therese Markow
- Unidad de Genómica Avanzada (Langebio), CINVESTAV, Irapuato, GTO 36824, México
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - José M Ranz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92647, USA
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7
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Höglund A, Henriksen R, Churcher AM, Guerrero-Bosagna CM, Martinez-Barrio A, Johnsson M, Jensen P, Wright D. The regulation of methylation on the Z chromosome and the identification of multiple novel Male Hyper-Methylated regions in the chicken. PLoS Genet 2024; 20:e1010719. [PMID: 38457441 PMCID: PMC10954189 DOI: 10.1371/journal.pgen.1010719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 03/20/2024] [Accepted: 01/31/2024] [Indexed: 03/10/2024] Open
Abstract
DNA methylation is a key regulator of eukaryote genomes, and is of particular relevance in the regulation of gene expression on the sex chromosomes, with a key role in dosage compensation in mammalian XY systems. In the case of birds, dosage compensation is largely absent, with it being restricted to two small Male Hyper-Methylated (MHM) regions on the Z chromosome. To investigate how variation in DNA methylation is regulated on the Z chromosome we utilised a wild x domestic advanced intercross in the chicken, with both hypothalamic methylomes and transcriptomes assayed in 124 individuals. The relatively large numbers of individuals allowed us to identify additional genomic MHM regions on the Z chromosome that were significantly differentially methylated between the sexes. These regions appear to down-regulate local gene expression in males, but not remove it entirely (unlike the lncRNAs identified in the initial MHM regions). These MHM regions were further tested and the most balanced genes appear to show decreased expression in males, whilst methylation appeared to be far more correlated with gene expression in the less balanced, as compared to the most balanced genes. In addition, quantitative trait loci (QTL) that regulate variation in methylation on the Z chromosome, and those loci that regulate methylation on the autosomes that derive from the Z chromosome were mapped. Trans-effect hotspots were also identified that were based on the autosomes but affected the Z, and also one that was based on the Z chromosome but that affected both autosomal and sex chromosome DNA methylation regulation. We show that both cis and trans loci that originate from the Z chromosome never exhibit an interaction with sex, whereas trans loci originating from the autosomes but affecting the Z chromosome always display such an interaction. Our results highlight how additional MHM regions are actually present on the Z chromosome, and they appear to have smaller-scale effects on gene expression in males. Quantitative variation in methylation is also regulated both from the autosomes to the Z chromosome, and from the Z chromosome to the autosomes.
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Affiliation(s)
- Andrey Höglund
- Science for Life Laboratory, Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | - Rie Henriksen
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | | | - Carlos M. Guerrero-Bosagna
- Physiology and Environmental Toxicology Program, Department of Organismal Biology, Uppsala University, Uppsala, Sweden
| | | | - Martin Johnsson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Per Jensen
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Dominic Wright
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
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8
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Muralidhar P, Coop G. Polygenic response of sex chromosomes to sexual antagonism. Evolution 2024; 78:539-554. [PMID: 38153370 PMCID: PMC10903542 DOI: 10.1093/evolut/qpad231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 11/30/2023] [Accepted: 12/22/2023] [Indexed: 12/29/2023]
Abstract
Sexual antagonism occurs when males and females differ in their phenotypic fitness optima but are constrained in their evolution to these optima because of their shared genome. The sex chromosomes, which have distinct evolutionary "interests" relative to the autosomes, are theorized to play an important role in sexually antagonistic conflict. However, the evolutionary responses of sex chromosomes and autosomes have usually been considered independently, that is, via contrasting the response of a gene located on either an X chromosome or an autosome. Here, we study the coevolutionary response of the X chromosome and autosomes to sexually antagonistic selection acting on a polygenic phenotype. We model a phenotype initially under stabilizing selection around a single optimum, followed by a sudden divergence of the male and female optima. We find that, in the absence of dosage compensation, the X chromosome promotes evolution toward the female optimum, inducing coevolutionary male-biased responses on the autosomes. Dosage compensation obscures the female-biased interests of the X, causing it to contribute equally to male and female phenotypic change. We further demonstrate that fluctuations in an adaptive landscape can generate prolonged intragenomic conflict and accentuate the differential responses of the X and autosomes to this conflict.
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Affiliation(s)
- Pavitra Muralidhar
- Center for Population Biology, University of California, Davis, CA, United States
- Department of Evolution and Ecology, University of California, Davis, CA, United States
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, United States
| | - Graham Coop
- Center for Population Biology, University of California, Davis, CA, United States
- Department of Evolution and Ecology, University of California, Davis, CA, United States
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9
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Bravo‐Estupiñan DM, Aguilar‐Guerrero K, Quirós S, Acón M, Marín‐Müller C, Ibáñez‐Hernández M, Mora‐Rodríguez RA. Gene dosage compensation: Origins, criteria to identify compensated genes, and mechanisms including sensor loops as an emerging systems-level property in cancer. Cancer Med 2023; 12:22130-22155. [PMID: 37987212 PMCID: PMC10757140 DOI: 10.1002/cam4.6719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023] Open
Abstract
The gene dosage compensation hypothesis presents a mechanism through which the expression of certain genes is modulated to compensate for differences in the dose of genes when additional chromosomes are present. It is one of the means through which cancer cells actively cope with the potential damaging effects of aneuploidy, a hallmark of most cancers. Dosage compensation arises through several processes, including downregulation or overexpression of specific genes and the relocation of dosage-sensitive genes. In cancer, a majority of compensated genes are generally thought to be regulated at the translational or post-translational level, and include the basic components of a compensation loop, including sensors of gene dosage and modulators of gene expression. Post-translational regulation is mostly undertaken by a general degradation or aggregation of remaining protein subunits of macromolecular complexes. An increasingly important role has also been observed for transcriptional level regulation. This article reviews the process of targeted gene dosage compensation in cancer and other biological conditions, along with the mechanisms by which cells regulate specific genes to restore cellular homeostasis. These mechanisms represent potential targets for the inhibition of dosage compensation of specific genes in aneuploid cancers. This article critically examines the process of targeted gene dosage compensation in cancer and other biological contexts, alongside the criteria for identifying genes subject to dosage compensation and the intricate mechanisms by which cells orchestrate the regulation of specific genes to reinstate cellular homeostasis. Ultimately, our aim is to gain a comprehensive understanding of the intricate nature of a systems-level property. This property hinges upon the kinetic parameters of regulatory motifs, which we have termed "gene dosage sensor loops." These loops have the potential to operate at both the transcriptional and translational levels, thus emerging as promising candidates for the inhibition of dosage compensation in specific genes. Additionally, they represent novel and highly specific therapeutic targets in the context of aneuploid cancer.
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Affiliation(s)
- Diana M. Bravo‐Estupiñan
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Programa de Doctorado en Ciencias, Sistema de Estudios de Posgrado (SEP)Universidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Terapia Génica, Departamento de BioquímicaEscuela Nacional de Ciencias Biológicas del Instituto Politécnico NacionalCiudad de MéxicoMexico
- Speratum Biopharma, Inc.Centro Nacional de Innovación Biotecnológica Nacional (CENIBiot)San JoséCosta Rica
| | - Karol Aguilar‐Guerrero
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Maestría académica en Microbiología, Programa de Posgrado en Microbiología, Parasitología, Química Clínica e InmunologíaUniversidad de Costa RicaSan JoséCosta Rica
| | - Steve Quirós
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Quimiosensibilidad tumoral (LQT), Centro de Investigación en enfermedades Tropicales (CIET), Facultad de MicrobiologíaUniversidad de Costa RicaSan JoséCosta Rica
| | - Man‐Sai Acón
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
| | - Christian Marín‐Müller
- Speratum Biopharma, Inc.Centro Nacional de Innovación Biotecnológica Nacional (CENIBiot)San JoséCosta Rica
| | - Miguel Ibáñez‐Hernández
- Laboratorio de Terapia Génica, Departamento de BioquímicaEscuela Nacional de Ciencias Biológicas del Instituto Politécnico NacionalCiudad de MéxicoMexico
| | - Rodrigo A. Mora‐Rodríguez
- CICICA, Centro de Investigación en Cirugía y Cáncer Research Center on Surgery and CancerUniversidad de Costa RicaSan JoséCosta Rica
- Laboratorio de Quimiosensibilidad tumoral (LQT), Centro de Investigación en enfermedades Tropicales (CIET), Facultad de MicrobiologíaUniversidad de Costa RicaSan JoséCosta Rica
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10
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Sultanova Z, Downing PA, Carazo P. Genetic sex determination, sex chromosome size and sex-specific lifespans across tetrapods. J Evol Biol 2023; 36:480-494. [PMID: 36537352 PMCID: PMC10107984 DOI: 10.1111/jeb.14130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 12/24/2022]
Abstract
Sex differences in lifespan are ubiquitous across the tree of life and exhibit broad taxonomic patterns that remain a puzzle, such as males living longer than females in birds and vice versa in mammals. The prevailing unguarded X hypothesis explains sex differences in lifespan by differential expression of recessive mutations on the X or Z chromosome of the heterogametic sex, but has only received indirect support to date. An alternative hypothesis is that the accumulation of deleterious mutations and repetitive elements on the Y or W chromosome might lower the survival of the heterogametic sex ('toxic Y' hypothesis). Here, we use a new database to report lower survival of the heterogametic relative to the homogametic sex across 136 species of birds, mammals, reptiles and amphibians, as expected if sex chromosomes shape sex-specific lifespans, and consistent with previous findings. We also found that the relative sizes of both the X and the Y chromosomes in mammals (but not the Z or the W chromosomes in birds) are associated with sex differences in lifespan, as predicted by the unguarded X and the 'toxic Y'. Furthermore, we report that the relative size of the Y is negatively associated with male lifespan in mammals, so that small Y size correlates with increased male lifespan. In theory, toxic Y effects are expected to be particularly strong in mammals, and we did not find similar effects in birds. Our results confirm the role of sex chromosomes in explaining sex differences in lifespan across tetrapods and further suggest that, at least in mammals, 'toxic Y' effects may play an important part in this role.
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Affiliation(s)
- Zahida Sultanova
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Philip A Downing
- Department of Biology, Lund University, Lund, Sweden.,Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Pau Carazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
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11
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Ma W, Rovatsos M. Sex chromosome evolution: The remarkable diversity in the evolutionary rates and mechanisms. J Evol Biol 2022; 35:1581-1588. [DOI: 10.1111/jeb.14119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 10/21/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022]
Affiliation(s)
- Wen‐Juan Ma
- Department of Molecular Biosciences University of Kansas Lawrence Kansas USA
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12
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Elkrewi M, Khauratovich U, Toups MA, Bett VK, Mrnjavac A, Macon A, Fraisse C, Sax L, Huylmans AK, Hontoria F, Vicoso B. ZW sex-chromosome evolution and contagious parthenogenesis in Artemia brine shrimp. Genetics 2022; 222:iyac123. [PMID: 35977389 PMCID: PMC9526061 DOI: 10.1093/genetics/iyac123] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Eurasian brine shrimp (genus Artemia) have closely related sexual and asexual lineages of parthenogenetic females, which produce rare males at low frequencies. Although they are known to have ZW chromosomes, these are not well characterized, and it is unclear whether they are shared across the clade. Furthermore, the underlying genetic architecture of the transmission of asexuality, which can occur when rare males mate with closely related sexual females, is not well understood. We produced a chromosome-level assembly for the sexual Eurasian species Artemia sinica and characterized in detail the pair of sex chromosomes of this species. We combined this new assembly with short-read genomic data for the sexual species Artemia sp. Kazakhstan and several asexual lineages of Artemia parthenogenetica, allowing us to perform an in-depth characterization of sex-chromosome evolution across the genus. We identified a small differentiated region of the ZW pair that is shared by all sexual and asexual lineages, supporting the shared ancestry of the sex chromosomes. We also inferred that recombination suppression has spread to larger sections of the chromosome independently in the American and Eurasian lineages. Finally, we took advantage of a rare male, which we backcrossed to sexual females, to explore the genetic basis of asexuality. Our results suggest that parthenogenesis is likely partly controlled by a locus on the Z chromosome, highlighting the interplay between sex determination and asexuality.
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Affiliation(s)
- Marwan Elkrewi
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | - Uladzislava Khauratovich
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna 1030, Austria
| | - Melissa A Toups
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
- Faculty of Science and Technology, Department of Life and Environmental Sciences, Bournemouth University, Poole BH12 5BB, UK
| | | | - Andrea Mrnjavac
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | - Ariana Macon
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
| | - Christelle Fraisse
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
- CNRS, Univ. Lille, UMR 8198—Evo-Eco-Paleo, 59000 Lille, France
| | - Luca Sax
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
- Lewis and Clark College, Portland, OR 97219, USA
| | - Ann Kathrin Huylmans
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
- Institute of Organismic and Molecular Evolution, Johannes Gutenberg Universität Mainz, Mainz 55122, Germany
| | - Francisco Hontoria
- Instituto de Acuicultura de Torre de la Sal (IATS-CSIC), 12595 Ribera de Cabanes (Castellón), Spain
| | - Beatriz Vicoso
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria
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13
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Kvistad L, Falk S, Austin L. Widespread genomic signatures of reproductive isolation and sex-specific selection in the Eastern Yellow Robin, Eopsaltria australis. G3 GENES|GENOMES|GENETICS 2022; 12:6605223. [PMID: 35686912 PMCID: PMC9438485 DOI: 10.1093/g3journal/jkac145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
How new species evolve is one of the most fundamental questions in biology. Population divergence, which may lead to speciation, may be occurring in the Eastern Yellow Robin, a common passerine that lives along the eastern coast of Australia. This species is composed of 2 parapatric lineages that have highly divergent mitochondrial DNA; however, similar levels of divergence have not been observed in the nuclear genome. Here we re-examine the nuclear genomes of these mitolineages to test potential mechanisms underlying the discordance between nuclear and mitochondrial divergence. We find that nuclear admixture occurs in a narrow hybrid zone, although the majority of markers across the genome show evidence of reproductive isolation between populations of opposing mitolineages. There is an 8 MB section of a previously identified putative neo-sex chromosome that is highly diverged between allopatric but not parapatric populations, which may be the result of a chromosomal inversion. The neo-sex chromosomal nature of this region, as well as the geographic patterns in which it exhibits divergence, suggest it is unlikely to be contributing to reproductive isolation through mitonuclear incompatibilities as reported in earlier studies. In addition, there are sex differences in the number of markers that are differentiated between populations of opposite mitolineages, with greater differentiation occurring in females, which are heterozygous, than males. These results suggest that, despite the absence of previously observed assortative mating, mitolineages of Eastern Yellow Robin experience at least some postzygotic isolation from each other, in a pattern consistent with Haldane’s Rule.
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Affiliation(s)
- Lynna Kvistad
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
| | - Stephanie Falk
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
- Deep Sequencing Facility, Max Planck Institute of Immunobiology and Epigenetics , Freiburg D-79108, Germany
| | - Lana Austin
- Biological Sciences, Monash University , Clayton, VIC 3800, Australia
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14
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Montgomery SA, Hisanaga T, Wang N, Axelsson E, Akimcheva S, Sramek M, Liu C, Berger F. Polycomb-mediated repression of paternal chromosomes maintains haploid dosage in diploid embryos of Marchantia. eLife 2022; 11:79258. [PMID: 35996955 PMCID: PMC9402228 DOI: 10.7554/elife.79258] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/18/2022] [Indexed: 02/06/2023] Open
Abstract
Complex mechanisms regulate gene dosage throughout eukaryotic life cycles. Mechanisms controlling gene dosage have been extensively studied in animals, however it is unknown how generalizable these mechanisms are to diverse eukaryotes. Here, we use the haploid plant Marchantia polymorpha to assess gene dosage control in its short-lived diploid embryo. We show that throughout embryogenesis, paternal chromosomes are repressed resulting in functional haploidy. The paternal genome is targeted for genomic imprinting by the Polycomb mark H3K27me3 starting at fertilization, rendering the maternal genome in control of embryogenesis. Maintaining haploid gene dosage by this new form of imprinting is essential for embryonic development. Our findings illustrate how haploid-dominant species can regulate gene dosage through paternal chromosome inactivation and initiates the exploration of the link between life cycle history and gene dosage in a broader range of organisms.
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Affiliation(s)
- Sean Akira Montgomery
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria.,Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Tetsuya Hisanaga
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Nan Wang
- Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Elin Axelsson
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Svetlana Akimcheva
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Milos Sramek
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Chang Liu
- Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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15
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Parker DJ, Jaron KS, Dumas Z, Robinson‐Rechavi M, Schwander T. X chromosomes show relaxed selection and complete somatic dosage compensation across
Timema
stick insect species. J Evol Biol 2022; 35:1734-1750. [PMID: 35933721 PMCID: PMC10087215 DOI: 10.1111/jeb.14075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/06/2022] [Accepted: 07/14/2022] [Indexed: 11/29/2022]
Abstract
Sex chromosomes have evolved repeatedly across the tree of life. As they are present in different copy numbers in males and females, they are expected to experience different selection pressures than the autosomes, with consequences including a faster rate of evolution, increased accumulation of sexually antagonistic alleles and the evolution of dosage compensation. Whether these consequences are general or linked to idiosyncrasies of specific taxa is not clear as relatively few taxa have been studied thus far. Here, we use whole-genome sequencing to identify and characterize the evolution of the X chromosome in five species of Timema stick insects with XX:X0 sex determination. The X chromosome had a similar size (approximately 12% of the genome) and gene content across all five species, suggesting that the X chromosome originated prior to the diversification of the genus. Genes on the X showed evidence of relaxed selection (elevated dN/dS) and a slower evolutionary rate (dN + dS) than genes on the autosomes, likely due to sex-biased mutation rates. Genes on the X also showed almost complete dosage compensation in somatic tissues (heads and legs), but dosage compensation was absent in the reproductive tracts. Contrary to prediction, sex-biased genes showed little enrichment on the X, suggesting that the advantage X-linkage provides to the accumulation of sexually antagonistic alleles is weak. Overall, we found the consequences of X-linkage on gene sequences and expression to be similar across Timema species, showing the characteristics of the X chromosome are surprisingly consistent over 30 million years of evolution.
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Affiliation(s)
- Darren J. Parker
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
- School of Natural Sciences Bangor University Bangor UK
| | - Kamil S. Jaron
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
- School of Biological Sciences Institute of Evolutionary Biology University of Edinburgh Edinburgh UK
| | - Zoé Dumas
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
| | - Marc Robinson‐Rechavi
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
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16
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Meisel RP, Asgari D, Schlamp F, Unckless RL. Induction and inhibition of Drosophila X chromosome gene expression are both impeded by the dosage compensation complex. G3 (BETHESDA, MD.) 2022; 12:6632659. [PMID: 35792851 PMCID: PMC9434221 DOI: 10.1093/g3journal/jkac165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/16/2022] [Indexed: 12/24/2022]
Abstract
Sex chromosomes frequently differ from the autosomes in the frequencies of genes with sexually dimorphic or tissue-specific expression. Multiple hypotheses have been put forth to explain the unique gene content of the X chromosome, including selection against male-beneficial X-linked alleles, expression limits imposed by the haploid dosage of the X in males, and interference by the dosage compensation complex on expression in males. Here, we investigate these hypotheses by examining differential gene expression in Drosophila melanogaster following several treatments that have widespread transcriptomic effects: bacterial infection, viral infection, and abiotic stress. We found that genes that are induced (upregulated) by these biotic and abiotic treatments are frequently under-represented on the X chromosome, but so are those that are repressed (downregulated) following treatment. We further show that whether a gene is bound by the dosage compensation complex in males can largely explain the paucity of both up- and downregulated genes on the X chromosome. Specifically, genes that are bound by the dosage compensation complex, or close to a dosage compensation complex high-affinity site, are unlikely to be up- or downregulated after treatment. This relationship, however, could partially be explained by a correlation between differential expression and breadth of expression across tissues. Nonetheless, our results suggest that dosage compensation complex binding, or the associated chromatin modifications, inhibit both up- and downregulation of X chromosome gene expression within specific contexts, including tissue-specific expression. We propose multiple possible mechanisms of action for the effect, including a role of Males absent on the first, a component of the dosage compensation complex, as a dampener of gene expression variance in both males and females. This effect could explain why the Drosophila X chromosome is depauperate in genes with tissue-specific or induced expression, while the mammalian X has an excess of genes with tissue-specific expression.
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Affiliation(s)
- Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, 3455 Cullen Blvd, Houston, TX 77204-5001, USA
| | - Danial Asgari
- Department of Biology and Biochemistry, University of Houston, 3455 Cullen Blvd, Houston, TX 77204-5001, USA
| | - Florencia Schlamp
- Department of Medicine, NYU Grossman School of Medicine, 435 E 30th St, New York, NY 10016, USA
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, 4055 Haworth Hall, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA
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17
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Li XY, Mei J, Ge CT, Liu XL, Gui JF. Sex determination mechanisms and sex control approaches in aquaculture animals. SCIENCE CHINA. LIFE SCIENCES 2022; 65:1091-1122. [PMID: 35583710 DOI: 10.1007/s11427-021-2075-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/14/2022] [Indexed: 01/21/2023]
Abstract
Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security. Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms, providing an ideal system to perform sex determination research, one of the important areas in life science. Moreover, sex is also one of the most valuable traits because sexual dimorphism in growth, size, and other economic characteristics commonly exist in aquaculture animals. Here, we synthesize current knowledge of sex determination mechanisms, sex chromosome evolution, reproduction strategies, and sexual dimorphism, and also review several approaches for sex control in aquaculture animals, including artificial gynogenesis, application of sex-specific or sex chromosome-linked markers, artificial sex reversal, as well as gene editing. We anticipate that better understanding of sex determination mechanisms and innovation of sex control approaches will facilitate sustainable development of aquaculture.
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Affiliation(s)
- Xi-Yin Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design, Institute of Hydrobiology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Wuhan, 430072, China
| | - Jie Mei
- College of Fisheries, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chu-Tian Ge
- College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo, 315100, China
| | - Xiao-Li Liu
- Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation of Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Jian-Fang Gui
- State Key Laboratory of Freshwater Ecology and Biotechnology, Hubei Hongshan Laboratory, The Innovative Academy of Seed Design, Institute of Hydrobiology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Wuhan, 430072, China.
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18
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Mank JE. Are plant and animal sex chromosomes really all that different? Philos Trans R Soc Lond B Biol Sci 2022; 377:20210218. [PMID: 35306885 PMCID: PMC8935310 DOI: 10.1098/rstb.2021.0218] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/12/2021] [Indexed: 12/19/2022] Open
Abstract
Sex chromosomes in plants have often been contrasted with those in animals with the goal of identifying key differences that can be used to elucidate fundamental evolutionary properties. For example, the often homomorphic sex chromosomes in plants have been compared to the highly divergent systems in some animal model systems, such as birds, Drosophila and therian mammals, with many hypotheses offered to explain the apparent dissimilarities, including the younger age of plant sex chromosomes, the lesser prevalence of sexual dimorphism, or the greater extent of haploid selection. Furthermore, many plant sex chromosomes lack complete sex chromosome dosage compensation observed in some animals, including therian mammals, Drosophila, some poeciliids, and Anolis, and plant dosage compensation, where it exists, appears to be incomplete. Even the canonical theoretical models of sex chromosome formation differ somewhat between plants and animals. However, the highly divergent sex chromosomes observed in some animal groups are actually the exception, not the norm, and many animal clades are far more similar to plants in their sex chromosome patterns. This begs the question of how different are plant and animal sex chromosomes, and which of the many unique properties of plants would be expected to affect sex chromosome evolution differently than animals? In fact, plant and animal sex chromosomes exhibit more similarities than differences, and it is not at all clear that they differ in terms of sexual conflict, dosage compensation, or even degree of divergence. Overall, the largest difference between these two groups is the greater potential for haploid selection in plants compared to animals. This may act to accelerate the expansion of the non-recombining region at the same time that it maintains gene function within it. This article is part of the theme issue 'Sex determination and sex chromosome evolution in land plants'.
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Affiliation(s)
- Judith E. Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, Canada
- Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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19
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Muyle A, Marais GAB, Bačovský V, Hobza R, Lenormand T. Dosage compensation evolution in plants: theories, controversies and mechanisms. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210222. [PMID: 35306896 PMCID: PMC8935305 DOI: 10.1098/rstb.2021.0222] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In a minority of flowering plants, separate sexes are genetically determined by sex chromosomes. The Y chromosome has a non-recombining region that degenerates, causing a reduced expression of Y genes. In some species, the lower Y expression is accompanied by dosage compensation (DC), a mechanism that re-equalizes male and female expression and/or brings XY male expression back to its ancestral level. Here, we review work on DC in plants, which started as early as the late 1960s with cytological approaches. The use of transcriptomics fired a controversy as to whether DC existed in plants. Further work revealed that various plants exhibit partial DC, including a few species with young and homomorphic sex chromosomes. We are starting to understand the mechanisms responsible for DC in some plants, but in most species, we lack the data to differentiate between global and gene-by-gene DC. Also, it is unknown why some species evolve many dosage compensated genes while others do not. Finally, the forces that drive DC evolution remain mysterious, both in plants and animals. We review the multiple evolutionary theories that have been proposed to explain DC patterns in eukaryotes with XY or ZW sex chromosomes. This article is part of the theme issue 'Sex determination and sex chromosome evolution in land plants'.
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Affiliation(s)
- Aline Muyle
- Laboratoire 'Biométrie et Biologie Evolutive', CNRS/Université Lyon 1, Lyon, France
| | - Gabriel A B Marais
- Laboratoire 'Biométrie et Biologie Evolutive', CNRS/Université Lyon 1, Lyon, France.,CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal.,Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, 4099-002 Porto, Portugal.,BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661 Vairão, Portugal
| | - Václav Bačovský
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno, Czech Republic
| | - Roman Hobza
- Department of Plant Developmental Genetics, Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, Brno, Czech Republic
| | - Thomas Lenormand
- CEFE, University of Montpellier, CNRS, EPHE, IRD, Montpellier, France
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20
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Lenormand T, Roze D. Y recombination arrest and degeneration in the absence of sexual dimorphism. Science 2022; 375:663-666. [PMID: 35143289 DOI: 10.1126/science.abj1813] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Current theory proposes that degenerated sex chromosomes-such as the mammalian Y-evolve through three steps: (i) recombination arrest, linking male-beneficial alleles to the Y chromosome; (ii) Y degeneration, resulting from the inefficacy of selection in the absence of recombination; and (iii) dosage compensation, correcting the resulting low expression of X-linked genes in males. We investigate a model of sex chromosome evolution that incorporates the coevolution of cis and trans regulators of gene expression. We show that the early emergence of dosage compensation favors the maintenance of Y-linked inversions by creating sex-antagonistic regulatory effects. This is followed by degeneration of these nonrecombining inversions caused by regulatory divergence between the X and Y chromosomes. In contrast to current theory, the whole process occurs without any selective pressure related to sexual dimorphism.
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Affiliation(s)
| | - Denis Roze
- CNRS, IRL 3614, Roscoff, France.,Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
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21
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Wang J, Xi Y, Ma S, Qi J, Li J, Zhang R, Han C, Li L, Wang J, Liu H. Single-molecule long-read sequencing reveals the potential impact of posttranscriptional regulation on gene dosage effects on the avian Z chromosome. BMC Genomics 2022; 23:122. [PMID: 35148676 PMCID: PMC8832729 DOI: 10.1186/s12864-022-08360-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 02/01/2022] [Indexed: 12/23/2022] Open
Abstract
Background Mammalian sex chromosomes provide dosage compensation, but avian lack a global mechanism of dose compensation. Herein, we employed nanopore sequencing to investigate the genetic basis of gene expression and gene dosage effects in avian Z chromosomes at the posttranscriptional level. Results In this study, the gonad and head skin of female and male duck samples (n = 4) were collected at 16 weeks of age for Oxford nanopore sequencing. Our results revealed a dosage effect and local regulation of duck Z chromosome gene expression. Additionally, AS and APA achieve tissue-specific gene expression, and male-biased lncRNA regulates its Z-linked target genes, with a positive regulatory role for gene dosage effects on the duck Z chromosome. In addition, GO enrichment and KEGG pathway analysis showed that the dosage effects of Z-linked genes were mainly associated with the cellular response to hormone stimulus, melanin biosynthetic, metabolic pathways, and melanogenesis, resulting in sex differences. Conclusions Our data suggested that post transcriptional regulation (AS, APA and lncRNA) has a potential impact on the gene expression effects of avian Z chromosomes. Our study provides a new view of gene regulation underlying the dose effects in avian Z chromosomes at the RNA post transcriptional level. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08360-8.
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Affiliation(s)
- Jianmei Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Yang Xi
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Shengchao Ma
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Jingjing Qi
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Junpeng Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Rongping Zhang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Chunchun Han
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Liang Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Jiwen Wang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, 613000, China.
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22
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Bronikowski AM, Meisel RP, Biga PR, Walters J, Mank JE, Larschan E, Wilkinson GS, Valenzuela N, Conard AM, de Magalhães JP, Duan J, Elias AE, Gamble T, Graze R, Gribble KE, Kreiling JA, Riddle NC. Sex-specific aging in animals: Perspective and future directions. Aging Cell 2022; 21:e13542. [PMID: 35072344 PMCID: PMC8844111 DOI: 10.1111/acel.13542] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/15/2021] [Accepted: 12/11/2021] [Indexed: 12/14/2022] Open
Abstract
Sex differences in aging occur in many animal species, and they include sex differences in lifespan, in the onset and progression of age-associated decline, and in physiological and molecular markers of aging. Sex differences in aging vary greatly across the animal kingdom. For example, there are species with longer-lived females, species where males live longer, and species lacking sex differences in lifespan. The underlying causes of sex differences in aging remain mostly unknown. Currently, we do not understand the molecular drivers of sex differences in aging, or whether they are related to the accepted hallmarks or pillars of aging or linked to other well-characterized processes. In particular, understanding the role of sex-determination mechanisms and sex differences in aging is relatively understudied. Here, we take a comparative, interdisciplinary approach to explore various hypotheses about how sex differences in aging arise. We discuss genomic, morphological, and environmental differences between the sexes and how these relate to sex differences in aging. Finally, we present some suggestions for future research in this area and provide recommendations for promising experimental designs.
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Affiliation(s)
- Anne M. Bronikowski
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Richard P. Meisel
- Department of Biology and BiochemistryUniversity of HoustonHoustonTexasUSA
| | - Peggy R. Biga
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
| | - James R. Walters
- Department of Ecology and Evolutionary BiologyThe University of KansasLawrenceKansasUSA
| | - Judith E. Mank
- Department of ZoologyUniversity of British ColumbiaVancouverBritish ColumbiaCanada
- Department of BioscienceUniversity of ExeterPenrynUK
| | - Erica Larschan
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | | | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIowaUSA
| | - Ashley Mae Conard
- Department of Computer ScienceCenter for Computational and Molecular BiologyBrown UniversityProvidenceRhode IslandUSA
| | - João Pedro de Magalhães
- Integrative Genomics of Ageing GroupInstitute of Ageing and Chronic DiseaseUniversity of LiverpoolLiverpoolUK
| | | | - Amy E. Elias
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Tony Gamble
- Department of Biological SciencesMarquette UniversityMilwaukeeWisconsinUSA
- Milwaukee Public MuseumMilwaukeeWisconsinUSA
- Bell Museum of Natural HistoryUniversity of MinnesotaSaint PaulMinnesotaUSA
| | - Rita M. Graze
- Department of Biological SciencesAuburn UniversityAuburnAlabamaUSA
| | - Kristin E. Gribble
- Josephine Bay Paul Center for Comparative Molecular Biology and EvolutionMarine Biological LaboratoryWoods HoleMassachusettsUSA
| | - Jill A. Kreiling
- Department of Molecular Biology, Cell Biology and BiochemistryBrown UniversityProvidenceRhode IslandUSA
| | - Nicole C. Riddle
- Department of BiologyThe University of Alabama at BirminghamBirminghamAlabamaUSA
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23
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Ramos L, Antunes A. Decoding sex: Elucidating sex determination and how high-quality genome assemblies are untangling the evolutionary dynamics of sex chromosomes. Genomics 2022; 114:110277. [PMID: 35104609 DOI: 10.1016/j.ygeno.2022.110277] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 12/22/2021] [Accepted: 01/26/2022] [Indexed: 11/28/2022]
Abstract
Sexual reproduction is a diverse and widespread process. In gonochoristic species, the differentiation of sexes occurs through diverse mechanisms, influenced by environmental and genetic factors. In most vertebrates, a master-switch gene is responsible for triggering a sex determination network. However, only a few genes have acquired master-switch functions, and this process is associated with the evolution of sex-chromosomes, which have a significant influence in evolution. Additionally, their highly repetitive regions impose challenges for high-quality sequencing, even using high-throughput, state-of-the-art techniques. Here, we review the mechanisms involved in sex determination and their role in the evolution of species, particularly vertebrates, focusing on sex chromosomes and the challenges involved in sequencing these genomic elements. We also address the improvements provided by the growth of sequencing projects, by generating a massive number of near-gapless, telomere-to-telomere, chromosome-level, phased assemblies, increasing the number and quality of sex-chromosome sequences available for further studies.
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Affiliation(s)
- Luana Ramos
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal; Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.
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24
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Ma S, Liu H, Wang J, Wang L, Xi Y, Liu Y, Xu Q, Hu J, Han C, Bai L, Li L, Wang J. Transcriptome Analysis Reveals Genes Associated With Sexual Dichromatism of Head Feather Color in Mallard. Front Genet 2021; 12:627974. [PMID: 34956302 PMCID: PMC8692775 DOI: 10.3389/fgene.2021.627974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/09/2021] [Indexed: 11/13/2022] Open
Abstract
Sexual dimorphism of feather color is typical in mallards, in which drakes exhibit green head feathers, while females show dull head feather color. We showed that more melanosomes deposited in the males' head's feather barbules than females and further form a two-dimensional hexagonal lattice, which conferred the green feather coloration of drakes. Additionally, transcriptome analysis revealed that some essential melanin biosynthesis genes were highly expressed in feather follicles during the development of green feathers, contributing to melanin deposition. We further identified 18 candidate differentially expressed genes, which may affect the sharp color differences between the males' head feathers, back feathers, and the females' head feathers. TYR and TYRP1 genes are associated with melanin biosynthesis directly. Their expressions in the males' head feather follicles were significantly higher than those in the back feather follicles and females' head feather follicles. Most clearly, the expression of TYRP1 was 256 and 32 times higher in the head follicles of males than in those of the female head and the male back, respectively. Hence, TYR and TYRP1 are probably the most critical candidate genes in DEGs. They may affect the sexual dimorphism of head feather color by cis-regulation of some transcription factors and the Z-chromosome dosage effect.
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Affiliation(s)
| | - Hehe Liu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, China
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25
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Basilicata MF, Keller Valsecchi CI. The good, the bad, and the ugly: Evolutionary and pathological aspects of gene dosage alterations. PLoS Genet 2021; 17:e1009906. [PMID: 34882671 PMCID: PMC8659298 DOI: 10.1371/journal.pgen.1009906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Diploid organisms contain a maternal and a paternal genome complement that is thought to provide robustness and allow developmental progression despite genetic perturbations that occur in heterozygosity. However, changes affecting gene dosage from the chromosome down to the individual gene level possess a significant pathological potential and can lead to developmental disorders (DDs). This indicates that expression from a balanced gene complement is highly relevant for proper cellular and organismal function in eukaryotes. Paradoxically, gene and whole chromosome duplications are a principal driver of evolution, while heteromorphic sex chromosomes (XY and ZW) are naturally occurring aneuploidies important for sex determination. Here, we provide an overview of the biology of gene dosage at the crossroads between evolutionary benefit and pathogenicity during disease. We describe the buffering mechanisms and cellular responses to alterations, which could provide a common ground for the understanding of DDs caused by copy number alterations.
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26
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Darolti I, Mank JE. A bioinformatic toolkit to simultaneously identify sex and sex-linked regions. Mol Ecol Resour 2021; 22:455-457. [PMID: 34662503 DOI: 10.1111/1755-0998.13530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/11/2021] [Indexed: 11/29/2022]
Abstract
Sex chromosomes are strange things, and often exhibit unusual patterns of diversity, rates of evolution, and gene regulation (Bachtrog et al., 2011, Mank, 2013). These unique features mean that although sex chromosomes are often a relatively small proportion of the genome, they are best identified and assessed separately from the autosomal majority when carrying out genomic analyses. However, identifying and partitioning genomic regions into sex-linked and autosomal in non-model species can often be quite difficult. In this issue of Molecular Ecology Resources, Nursyifa et al. (2021) provide a useful method that combines sequencing depth information with clustering models to assign sex to samples at the same time as identifying sex-linked scaffolds. This method gives robust results even with more challenging or low-quality data, and thus is particularly promising in studies of non-model organisms.
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Affiliation(s)
- Iulia Darolti
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Judith E Mank
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Ecology and Conservation, University of Exeter, Penryn, UK
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27
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Lindehell H, Glotov A, Dorafshan E, Schwartz YB, Larsson J. The role of H3K36 methylation and associated methyltransferases in chromosome-specific gene regulation. SCIENCE ADVANCES 2021; 7:eabh4390. [PMID: 34597135 PMCID: PMC10938550 DOI: 10.1126/sciadv.abh4390] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
In Drosophila, two chromosomes require special mechanisms to balance their transcriptional output to the rest of the genome. These are the male-specific lethal complex targeting the male X chromosome and Painting of fourth targeting chromosome 4. Here, we explore the role of histone H3 methylated at lysine-36 (H3K36) and the associated methyltransferases—Set2, NSD, and Ash1—in these two chromosome-specific systems. We show that the loss of Set2 impairs the MSL complex–mediated dosage compensation; however, the effect is not recapitulated by H3K36 replacement and indicates an alternative target of Set2. Unexpectedly, balanced transcriptional output from the fourth chromosome requires intact H3K36 and depends on the additive functions of NSD and Ash1. We conclude that H3K36 methylation and the associated methyltransferases are important factors to balance transcriptional output of the male X chromosome and the fourth chromosome. Furthermore, our study highlights the pleiotropic effects of these enzymes.
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Affiliation(s)
- Henrik Lindehell
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Alexander Glotov
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
| | - Eshagh Dorafshan
- Department of Molecular Biology, Umeå University, SE-90187 Umeå, Sweden
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28
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Mank JE, Rideout EJ. Developmental mechanisms of sex differences: from cells to organisms. Development 2021; 148:272484. [PMID: 34647574 DOI: 10.1242/dev.199750] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Male-female differences in many developmental mechanisms lead to the formation of two morphologically and physiologically distinct sexes. Although this is expected for traits with prominent differences between the sexes, such as the gonads, sex-specific processes also contribute to traits without obvious male-female differences, such as the intestine. Here, we review sex differences in developmental mechanisms that operate at several levels of biological complexity - molecular, cellular, organ and organismal - and discuss how these differences influence organ formation, function and whole-body physiology. Together, the examples we highlight show that one simple way to gain a more accurate and comprehensive understanding of animal development is to include both sexes.
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Affiliation(s)
- Judith E Mank
- Department of Zoology, Biodiversity Research Centre, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.,Biosciences, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK
| | - Elizabeth J Rideout
- Department of Cellular and Physiological Sciences, Life Sciences Institute, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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29
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Shnaf ASMA, Al-Khalifa MS. First constitutive heterochromatin characterization and Karyotype of white stork Ciconia ciconia (Aves: Ciconiidae). BRAZ J BIOL 2021; 83:e248814. [PMID: 34550286 DOI: 10.1590/1519-6984.248814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 04/27/2021] [Indexed: 11/22/2022] Open
Abstract
The karyotype and constitutive heterochromatin pattern of the white stork Ciconia ciconia samples obtained from Manzala lake, Dimiaat, Egypt was described. Somatic cells of Ciconia ciconia samples have diploid number 2n= 68 chromosomes. Out of 68 chromosomes, 11 pairs including sex chromosomes were macrochromosomes and the remaining pairs were microchromosomes. Of the 11 macrochromosome pairs, no.1, 2, 4 and 5 were submetacentric and pairs no. 6, 7 and 8 were described as metacentric. In addition, the autosome pair no.3 was subtelocentric, while autosome pair no.9 was acrocentric. Also, the sex chromosome Z represents the fourth one in size and it was classified as submetacentric while, W chromosome appeared as medium size and was acrocentric. Furthermore, C-banding pattern (constitutive heterochromatin) revealed variation in their sizes and occurrence between macrochromosomes. Pairs no. 7 and 8 of autosomes exhibited unusual distribution of heterochromatin, where they appeared as entirely heterochromatic. This may be related to the origin of sex chromosomes Z and W. However, there is no sufficient evidence illustrate the appearance of entirely heterochromatic autosomes. Therefore, there is no available cytogenetic literature that describes the C-banding and karyotype of Ciconia Ciconia, so the results herein are important and may assist in cytogenetic study and evolutionary pattern of Ciconiiformes.
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Affiliation(s)
- A S M Abu Shnaf
- Minia University, Faculty of Science, Department of Zoology and Entomology, Minia, Egypt
| | - M S Al-Khalifa
- King Saud University, College of Science, Department of Zoology, Riyadh, Saudi Arabia
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30
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Rovatsos M, Gamble T, Nielsen SV, Georges A, Ezaz T, Kratochvíl L. Do male and female heterogamety really differ in expression regulation? Lack of global dosage balance in pygopodid geckos. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200102. [PMID: 34304587 PMCID: PMC8310713 DOI: 10.1098/rstb.2020.0102] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2020] [Indexed: 12/25/2022] Open
Abstract
Differentiation of sex chromosomes is thought to have evolved with cessation of recombination and subsequent loss of genes from the degenerated partner (Y and W) of sex chromosomes, which in turn leads to imbalance of gene dosage between sexes. Based on work with traditional model species, theory suggests that unequal gene copy numbers lead to the evolution of mechanisms to counter this imbalance. Dosage compensation, or at least achieving dosage balance in expression of sex-linked genes between sexes, has largely been documented in lineages with male heterogamety (XX/XY sex determination), while ZZ/ZW systems are assumed to be usually associated with the lack of chromosome-wide gene dose regulatory mechanisms. Here, we document that although the pygopodid geckos evolved male heterogamety with a degenerated Y chromosome 32-72 Ma, one species in particular, Burton's legless lizard (Lialis burtonis), does not possess dosage balance in the expression of genes in its X-specific region. We summarize studies on gene dose regulatory mechanisms in animals and conclude that there is in them no significant dichotomy between male and female heterogamety. We speculate that gene dose regulatory mechanisms are likely to be related to the general mechanisms of sex determination instead of type of heterogamety. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.
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Affiliation(s)
- Michail Rovatsos
- Department of Ecology, Charles University, Prague, CZ 12844, Czech Republic
| | - Tony Gamble
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
- Milwaukee Public Museum, 800 W. Wells Street, Milwaukee, WI 53233, USA
- Bell Museum of Natural History, University of Minnesota, Saint Paul, MN 55108, USA
| | - Stuart V. Nielsen
- Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Arthur Georges
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Tariq Ezaz
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory 2617, Australia
| | - Lukáš Kratochvíl
- Department of Ecology, Charles University, Prague, CZ 12844, Czech Republic
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31
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Fraïsse C, Sachdeva H. The rates of introgression and barriers to genetic exchange between hybridizing species: sex chromosomes vs autosomes. Genetics 2021; 217:6042694. [PMID: 33724409 DOI: 10.1093/genetics/iyaa025] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
Interspecific crossing experiments have shown that sex chromosomes play a major role in reproductive isolation between many pairs of species. However, their ability to act as reproductive barriers, which hamper interspecific genetic exchange, has rarely been evaluated quantitatively compared to Autosomes. This genome-wide limitation of gene flow is essential for understanding the complete separation of species, and thus speciation. Here, we develop a mainland-island model of secondary contact between hybridizing species of an XY (or ZW) sexual system. We obtain theoretical predictions for the frequency of introgressed alleles, and the strength of the barrier to neutral gene flow for the two types of chromosomes carrying multiple interspecific barrier loci. Theoretical predictions are obtained for scenarios where introgressed alleles are rare. We show that the same analytical expressions apply for sex chromosomes and autosomes, but with different sex-averaged effective parameters. The specific features of sex chromosomes (hemizygosity and absence of recombination in the heterogametic sex) lead to reduced levels of introgression on the X (or Z) compared to autosomes. This effect can be enhanced by certain types of sex-biased forces, but it remains overall small (except when alleles causing incompatibilities are recessive). We discuss these predictions in the light of empirical data comprising model-based tests of introgression and cline surveys in various biological systems.
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Affiliation(s)
- Christelle Fraïsse
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.,CNRS, Univ. Lille, UMR 8198 - Evo-Eco-Paleo, F-59000 Lille, France
| | - Himani Sachdeva
- Institute of Science and Technology Austria, Klosterneuburg 3400, Austria.,Mathematics and BioSciences Group, Faculty of Mathematics, University of Vienna, A-1090 Vienna, Austria
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32
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Bista B, Wu Z, Literman R, Valenzuela N. Thermosensitive sex chromosome dosage compensation in ZZ/ZW softshell turtles, Apalone spinifera. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200101. [PMID: 34304598 DOI: 10.1098/rstb.2020.0101] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Sex chromosome dosage compensation (SCDC) overcomes gene-dose imbalances that disturb transcriptional networks, as when ZW females or XY males are hemizygous for Z/X genes. Mounting data from non-model organisms reveal diverse SCDC mechanisms, yet their evolution remains obscure, because most informative lineages with variable sex chromosomes are unstudied. Here, we discovered SCDC in turtles and an unprecedented thermosensitive SCDC in eukaryotes. We contrasted RNA-seq expression of Z-genes, their autosomal orthologues, and control autosomal genes in Apalone spinifera (ZZ/ZW) and Chrysemys picta turtles with temperature-dependent sex determination (TSD) (proxy for ancestral expression). This approach disentangled chromosomal context effects on Z-linked and autosomal expression, from lineage effects owing to selection or drift. Embryonic Apalone SCDC is tissue- and age-dependent, regulated gene-by-gene, complete in females via Z-upregulation in both sexes (Type IV) but partial and environmentally plastic via Z-downregulation in males (accentuated at colder temperature), present in female hatchlings and a weakly suggestive in adult liver (Type I). Results indicate that embryonic SCDC evolved with/after sex chromosomes in Apalone's family Tryonichidae, while co-opting Z-gene upregulation present in the TSD ancestor. Notably, Apalone's SCDC resembles pygmy snake's, and differs from the full-SCDC of Anolis lizards who share homologous sex chromosomes (XY), advancing our understanding of how XX/XY and ZZ/ZW systems compensate gene-dose imbalance. This article is part of the theme issue 'Challenging the paradigm in sex chromosome evolution: empirical and theoretical insights with a focus on vertebrates (Part II)'.
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Affiliation(s)
- Basanta Bista
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Zhiqiang Wu
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA.,Guangdong Laboratory for Lingnan Modern Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, People's Republic of China
| | - Robert Literman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
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33
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Metzger DCH, Sandkam BA, Darolti I, Mank JE. Rapid Evolution of Complete Dosage Compensation in Poecilia. Genome Biol Evol 2021; 13:6317675. [PMID: 34240180 PMCID: PMC8325565 DOI: 10.1093/gbe/evab155] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2021] [Indexed: 12/13/2022] Open
Abstract
Dosage compensation balances gene expression between the sexes in systems with diverged heterogametic sex chromosomes. Theory predicts that dosage compensation should rapidly evolve in tandem with the divergence of sex chromosomes to prevent the deleterious effects of dosage imbalances that occur as a result of sex chromosome divergence. Examples of complete dosage compensation, where gene expression of the entire sex chromosome is compensated, are rare, and have only been found in relatively ancient sex chromosome systems. Consequently, very little is known about the evolutionary dynamics of complete dosage compensation systems. Within the family Poeciliidae the subgenus Lebistes share the same sex chromosome system which originated 18.48–26.08 Ma. In Poecilia reticulata and P. wingei, the Y chromosome has been largely maintained, whereas the Y in the closely related species P. picta and P. parae has rapidly degraded. We recently found P. picta to be the first example of complete dosage compensation in a fish. Here, we show that P. parae also has complete dosage compensation, thus complete dosage compensation likely evolved in the short (∼3.7 Myr) interval after the split of the ancestor of these two species from P. reticulata, but before they diverged from each other. These data suggest that novel dosage compensation mechanisms can evolve rapidly, thus supporting the longstanding theoretical prediction that such mechanisms arise in tandem with rapidly diverging sex chromosomes.
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Affiliation(s)
- David C H Metzger
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Canada
| | - Benjamin A Sandkam
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Canada
| | - Iulia Darolti
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Canada
| | - Judith E Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Canada.,Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall, United Kingdom
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34
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A de novo transcriptional atlas in Danaus plexippus reveals variability in dosage compensation across tissues. Commun Biol 2021; 4:791. [PMID: 34172835 PMCID: PMC8233437 DOI: 10.1038/s42003-021-02335-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 06/09/2021] [Indexed: 02/06/2023] Open
Abstract
A detailed knowledge of gene function in the monarch butterfly is still lacking. Here we generate a genome assembly from a Mexican nonmigratory population and used RNA-seq data from 14 biological samples for gene annotation and to construct an atlas portraying the breadth of gene expression during most of the monarch life cycle. Two thirds of the genes show expression changes, with long noncoding RNAs being particularly finely regulated during adulthood, and male-biased expression being four times more common than female-biased. The two portions of the monarch heterochromosome Z, one ancestral to the Lepidoptera and the other resulting from a chromosomal fusion, display distinct association with sex-biased expression, reflecting sample-dependent incompleteness or absence of dosage compensation in the ancestral but not the novel portion of the Z. This study presents extended genomic and transcriptomic resources that will facilitate a better understanding of the monarch's adaptation to a changing environment.
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35
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Son JH, Meisel RP. Gene-Level, but Not Chromosome-Wide, Divergence between a Very Young House Fly Proto-Y Chromosome and Its Homologous Proto-X Chromosome. Mol Biol Evol 2021; 38:606-618. [PMID: 32986844 PMCID: PMC7826193 DOI: 10.1093/molbev/msaa250] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
X and Y chromosomes are usually derived from a pair of homologous autosomes, which then diverge from each other over time. Although Y-specific features have been characterized in sex chromosomes of various ages, the earliest stages of Y chromosome evolution remain elusive. In particular, we do not know whether early stages of Y chromosome evolution consist of changes to individual genes or happen via chromosome-scale divergence from the X. To address this question, we quantified divergence between young proto-X and proto-Y chromosomes in the house fly, Musca domestica. We compared proto-sex chromosome sequence and gene expression between genotypic (XY) and sex-reversed (XX) males. We find evidence for sequence divergence between genes on the proto-X and proto-Y, including five genes with mitochondrial functions. There is also an excess of genes with divergent expression between the proto-X and proto-Y, but the number of genes is small. This suggests that individual proto-Y genes, but not the entire proto-Y chromosome, have diverged from the proto-X. We identified one gene, encoding an axonemal dynein assembly factor (which functions in sperm motility), that has higher expression in XY males than XX males because of a disproportionate contribution of the proto-Y allele to gene expression. The upregulation of the proto-Y allele may be favored in males because of this gene's function in spermatogenesis. The evolutionary divergence between proto-X and proto-Y copies of this gene, as well as the mitochondrial genes, is consistent with selection in males affecting the evolution of individual genes during early Y chromosome evolution.
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Affiliation(s)
- Jae Hak Son
- Department of Biology and Biochemistry, University of Houston, Houston, TX.,Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT
| | - Richard P Meisel
- Department of Biology and Biochemistry, University of Houston, Houston, TX
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36
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Chae T, Harkess A, Moore RC. Sex-linked gene expression and the emergence of hermaphrodites in Carica papaya. AMERICAN JOURNAL OF BOTANY 2021; 108:1029-1041. [PMID: 34156700 DOI: 10.1002/ajb2.1689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 02/08/2021] [Indexed: 06/13/2023]
Abstract
PREMISE One evolutionary path from hermaphroditism to dioecy is via a gynodioecious intermediate. The evolution of dioecy may also coincide with the formation of sex chromosomes that possess sex-determining loci that are physically linked in a region of suppressed recombination. Dioecious papaya (Carica papaya) has an XY chromosome system, where the presence of a Y chromosome determines maleness. However, in cultivation, papaya is gynodioecious, due to the conversion of the male Y chromosome to a hermaphroditic Yh chromosome during its domestication. METHODS We investigated gene expression linked to the X, Y, and Yh chromosomes at different floral developmental stages to identify differentially expressed genes that may be involved in the sexual transition of males to hermaphrodites. RESULTS We identified 309 sex-biased genes found on the sex chromosomes, most of which are found in the pseudoautosomal regions. Female (XX) expression in the sex-determining region was almost double that of X-linked expression in males (XY) and hermaphrodites (XYh ), which rules out dosage compensation for most sex-linked genes; although, an analysis of hemizygous X-linked loci found evidence of partial dosage compensation. Furthermore, we identified a candidate gene associated with sex determination and the transition to hermaphroditism, a homolog of the MADS-box protein SHORT VEGETATIVE PHASE. CONCLUSIONS We identified a pattern of partial dosage compensation for hemizygous genes located in the papaya sex-determining region. Furthermore, we propose that loss-of-expression of the Y-linked SHORT VEGETATIVE PHASE homolog facilitated the transition from males to hermaphrodites in papaya.
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Affiliation(s)
- Taylor Chae
- Department of Biology, Miami University, Oxford, OH
| | - Alex Harkess
- Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL
- HudsonAlpha Institute for Biotechnology, Huntsville, AL
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37
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Ko MC, Frankl-Vilches C, Bakker A, Gahr M. The Gene Expression Profile of the Song Control Nucleus HVC Shows Sex Specificity, Hormone Responsiveness, and Species Specificity Among Songbirds. Front Neurosci 2021; 15:680530. [PMID: 34135731 PMCID: PMC8200640 DOI: 10.3389/fnins.2021.680530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Singing occurs in songbirds of both sexes, but some species show typical degrees of sex-specific performance. We studied the transcriptional sex differences in the HVC, a brain nucleus critical for song pattern generation, of the forest weaver (Ploceus bicolor), the blue-capped cordon-bleu (Uraeginthus cyanocephalus), and the canary (Serinus canaria), which are species that show low, medium, and high levels of sex-specific singing, respectively. We observed persistent sex differences in gene expression levels regardless of the species-specific sexual singing phenotypes. We further studied the HVC transcriptomes of defined phenotypes of canary, known for its testosterone-sensitive seasonal singing. By studying both sexes of canaries during both breeding and non-breeding seasons, non-breeding canaries treated with testosterone, and spontaneously singing females, we found that the circulating androgen levels and sex were the predominant variables associated with the variations in the HVC transcriptomes. The comparison of natural singing with testosterone-induced singing in canaries of the same sex revealed considerable differences in the HVC transcriptomes. Strong transcriptional changes in the HVC were detected during the transition from non-singing to singing in canaries of both sexes. Although the sex-specific genes of singing females shared little resemblance with those of males, our analysis showed potential functional convergences. Thus, male and female songbirds achieve comparable singing behaviours with sex-specific transcriptomes.
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Affiliation(s)
- Meng-Ching Ko
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Carolina Frankl-Vilches
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Antje Bakker
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for Ornithology, Seewiesen, Germany
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Genome assembly, sex-biased gene expression and dosage compensation in the damselfly Ischnura elegans. Genomics 2021; 113:1828-1837. [PMID: 33831439 DOI: 10.1016/j.ygeno.2021.04.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 02/27/2021] [Accepted: 04/04/2021] [Indexed: 12/14/2022]
Abstract
The evolution of sex chromosomes, and patterns of sex-biased gene expression and dosage compensation, are poorly known among early winged insects such as odonates. We assembled and annotated the genome of Ischnura elegans (blue-tailed damselfly), which, like other odonates, has a male-hemigametic sex-determining system (X0 males, XX females). By identifying X-linked genes in I. elegans and their orthologs in other insect genomes, we found homologies between the X chromosome in odonates and chromosomes of other orders, including the X chromosome in Coleoptera. Next, we showed balanced expression of X-linked genes between sexes in adult I. elegans, i.e. evidence of dosage compensation. Finally, among the genes in the sex-determining pathway only fruitless was found to be X-linked, while only doublesex showed sex-biased expression. This study reveals partly conserved sex chromosome synteny and independent evolution of dosage compensation among insect orders separated by several hundred million years of evolutionary history.
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Rayner JG, Hitchcock TJ, Bailey NW. Variable dosage compensation is associated with female consequences of an X-linked, male-beneficial mutation. Proc Biol Sci 2021; 288:20210355. [PMID: 33757350 PMCID: PMC8059673 DOI: 10.1098/rspb.2021.0355] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 03/01/2021] [Indexed: 12/13/2022] Open
Abstract
Recent theory has suggested that dosage compensation mediates sexual antagonism over X-linked genes. This process relies on the assumption that dosage compensation scales phenotypic effects between the sexes, which is largely untested. We evaluated this by quantifying transcriptome variation associated with a recently arisen, male-beneficial, X-linked mutation across tissues of the field cricket Teleogryllus oceanicus, and testing the relationship between the completeness of dosage compensation and female phenotypic effects at the level of gene expression. Dosage compensation in T. oceanicus was variable across tissues but usually incomplete, such that relative expression of X-linked genes was typically greater in females. Supporting the assumption that dosage compensation scales phenotypic effects between the sexes, we found tissues with incomplete dosage compensation tended to show female-skewed effects of the X-linked allele. In gonads, where expression of X-linked genes was most strongly female-biased, ovaries-limited genes were much more likely to be X-linked than were testes-limited genes, supporting the view that incomplete dosage compensation favours feminization of the X. Our results support the expectation that sex chromosome dosage compensation scales phenotypic effects of X-linked genes between sexes, substantiating a key assumption underlying the theoretical role of dosage compensation in determining the dynamics of sexual antagonism on the X.
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Affiliation(s)
- Jack G. Rayner
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | - Thomas J. Hitchcock
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
| | - Nathan W. Bailey
- Centre for Biological Diversity, University of St Andrews, St Andrews KY16 9TH, UK
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Transcriptional regulation of dosage compensation in Carica papaya. Sci Rep 2021; 11:5854. [PMID: 33712672 PMCID: PMC7971000 DOI: 10.1038/s41598-021-85480-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/22/2021] [Indexed: 12/13/2022] Open
Abstract
Sex chromosome evolution results in the disparity in gene content between heterogametic sex chromosomes and creates the need for dosage compensation to counteract the effects of gene dose imbalance of sex chromosomes in males and females. It is not known at which stage of sex chromosome evolution dosage compensation would evolve. We used global gene expression profiling in male and female papayas to assess gene expression patterns of sex-linked genes on the papaya sex chromosomes. By analyzing expression ratios of sex-linked genes to autosomal genes and sex-linked genes in males relative to females, our results showed that dosage compensation was regulated on a gene-by-gene level rather than whole sex-linked region in papaya. Seven genes on the papaya X chromosome exhibited dosage compensation. We further compared gene expression ratios in the two evolutionary strata. Y alleles in the older evolutionary stratum showed reduced expression compared to X alleles, while Y alleles in the younger evolutionary stratum showed elevated expression compared to X alleles. Reduced expression of Y alleles in the older evolutionary stratum might be caused by accumulation of deleterious mutations in regulatory regions or transposable element-mediated methylation spreading. Most X-hemizygous genes exhibited either no or very low expression, suggesting that gene silencing might play a role in maintaining transcriptional balance between females and males.
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Rovatsos M, Kratochvíl L. Evolution of dosage compensation does not depend on genomic background. Mol Ecol 2021; 30:1836-1845. [PMID: 33606326 DOI: 10.1111/mec.15853] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 02/14/2021] [Accepted: 02/15/2021] [Indexed: 12/30/2022]
Abstract
Organisms have evolved various mechanisms to cope with the differences in the gene copy numbers between sexes caused by degeneration of Y and W sex chromosomes. Complete dosage compensation or at least expression balance between sexes has been reported predominantly in XX/XY systems, but rarely in ZZ/ZW systems. However, this often-reported pattern is based on comparisons of lineages where sex chromosomes evolved from nonhomologous genomic regions, potentially differing in sensitivity to differences in gene copy numbers. Here we document that two reptilian lineages (XX/XY iguanas and ZZ/ZW softshell turtles), which independently co-opted the same ancestral genomic region for the function of sex chromosomes, evolved different gene dose regulatory mechanisms. The independent co-option of the same genomic region for the role of sex chromosomes as in the iguanas and the softshell turtles offers great opportunity for testing evolutionary scenarios on sex chromosome evolution under the explicit control of the genomic background and gene identity. We show that the parallel loss of functional genes from the Y chromosome of the green anole and the W chromosome of the Florida softshell turtle led to different dosage compensation mechanisms. Our approach controlling for genetic background thus does not support that the variability in the regulation of gene dose differences is a consequence of ancestral autosomal gene content.
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Affiliation(s)
- Michail Rovatsos
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lukáš Kratochvíl
- Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
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The evolution of sex chromosome dosage compensation in animals. J Genet Genomics 2020; 47:681-693. [PMID: 33579636 DOI: 10.1016/j.jgg.2020.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/03/2020] [Accepted: 10/04/2020] [Indexed: 02/02/2023]
Abstract
The evolution of heteromorphic sex chromosomes shall lead to gene expression dosage problems, as in at least one of the sexes, the sex-linked gene dose has been reduced by half. It has been proposed that the transcriptional output of the whole X or Z chromosome should be doubled for complete dosage compensation in heterogametic sex. However, owing to the variability of the existing methods to determine the transcriptional differences between sex chromosomes and autosomes (S:A ratios) in different studies, we collected more than 500 public RNA-Seq data set from multiple tissues and species in major clades and proposed a unified computational framework for unbiased and comparable measurement of the S:A ratios of multiple species. We also tested the evolution of dosage compensation more directly by assessing changes in the expression levels of the current sex-linked genes relative to those of the ancestral sex-linked genes. We found that in mammals and birds, the S:A ratio is approximately 0.5, whereas in insects, fishes, and flatworms, the S:A ratio is approximately 1.0. Further analysis showed that the fraction of dosage-sensitive housekeeping genes on the X/Z chromosome is significantly correlated with the S:A ratio. In addition, the degree of degeneration of the Y chromosome may be responsible for the change in the S:A ratio in mammals without a dosage compensation mechanism. Our observations offer unequivocal support for the sex chromosome insensitivity hypothesis in animals and suggest that dosage sensitivity states of sex chromosomes are a major factor underlying different evolutionary strategies of dosage compensation.
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Singchat W, Ahmad SF, Laopichienpong N, Suntronpong A, Panthum T, Griffin DK, Srikulnath K. Snake W Sex Chromosome: The Shadow of Ancestral Amniote Super-Sex Chromosome. Cells 2020; 9:cells9112386. [PMID: 33142713 PMCID: PMC7692289 DOI: 10.3390/cells9112386] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 12/20/2022] Open
Abstract
: Heteromorphic sex chromosomes, particularly the ZZ/ZW sex chromosome system of birds and some reptiles, undergo evolutionary dynamics distinct from those of autosomes. The W sex chromosome is a unique karyological member of this heteromorphic pair, which has been extensively studied in snakes to explore the origin, evolution, and genetic diversity of amniote sex chromosomes. The snake W sex chromosome offers a fascinating model system to elucidate ancestral trajectories that have resulted in genetic divergence of amniote sex chromosomes. Although the principal mechanism driving evolution of the amniote sex chromosome remains obscure, an emerging hypothesis, supported by studies of W sex chromosomes of squamate reptiles and snakes, suggests that sex chromosomes share varied genomic blocks across several amniote lineages. This implies the possible split of an ancestral super-sex chromosome via chromosomal rearrangements. We review the major findings pertaining to sex chromosomal profiles in amniotes and discuss the evolution of an ancestral super-sex chromosome by collating recent evidence sourced mainly from the snake W sex chromosome analysis. We highlight the role of repeat-mediated sex chromosome conformation and present a genomic landscape of snake Z and W chromosomes, which reveals the relative abundance of major repeats, and identifies the expansion of certain transposable elements. The latest revolution in chromosomics, i.e., complete telomere-to-telomere assembly, offers mechanistic insights into the evolutionary origin of sex chromosomes.
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Affiliation(s)
- Worapong Singchat
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
| | - Syed Farhan Ahmad
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
| | - Nararat Laopichienpong
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
| | - Aorarat Suntronpong
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
| | - Thitipong Panthum
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
| | | | - Kornsorn Srikulnath
- Laboratory of Animal Cytogenetics and Comparative Genomics (ACCG), Department of Genetics, Faculty of Science, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand; (W.S.); (S.F.A.); (N.L.); (A.S.); (T.P.)
- Special Research Unit for Wildlife Genomics (SRUWG), Department of Forest Biology, Faculty of Forestry, Kasetsart University, 50 Ngamwongwan, Chatuchak, Bangkok 10900, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Kasetsart University, (CASTNAR, NRU-KU, Thailand), Bangkok 10900, Thailand
- Center of Excellence on Agricultural Biotechnology (AG-BIO/PERDO-CHE), Bangkok 10900, Thailand
- Omics Center for Agriculture, Bioresources, Food and Health, Kasetsart University (OmiKU), Bangkok 10900, Thailand
- Amphibian Research Center, Hiroshima University, 1-3-1, Kagamiyama, Higashihiroshima 739-8526, Japan
- Correspondence: ; Tel.: +66-2562-5644
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Martinez-Ruiz C, Pracana R, Stolle E, Paris CI, Nichols RA, Wurm Y. Genomic architecture and evolutionary antagonism drive allelic expression bias in the social supergene of red fire ants. eLife 2020; 9:55862. [PMID: 32773032 PMCID: PMC7476760 DOI: 10.7554/elife.55862] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 08/07/2020] [Indexed: 11/17/2022] Open
Abstract
Supergene regions maintain alleles of multiple genes in tight linkage through suppressed recombination. Despite their importance in determining complex phenotypes, our empirical understanding of early supergene evolution is limited. Here we focus on the young ‘social’ supergene of fire ants, a powerful system for disentangling the effects of evolutionary antagonism and suppressed recombination. We hypothesize that gene degeneration and social antagonism shaped the evolution of the fire ant supergene, resulting in distinct patterns of gene expression. We test these ideas by identifying allelic differences between supergene variants, characterizing allelic expression across populations, castes and body parts, and contrasting allelic expression biases with differences in expression between social forms. We find strong signatures of gene degeneration and gene-specific dosage compensation. On this background, a small portion of the genes has the signature of adaptive responses to evolutionary antagonism between social forms. Red fire ants (Solenopsis invicta) are native to South America, but the species has spread to North America, Australia and New Zealand where it can be an invasive pest. A reason for this species’ invasiveness types of colonies : one with a single egg-laying queen and another with several queens. However, it is not possible to simply add more queens to a colony with one queen. Instead, the number of queens in a colony is controlled genetically, by a chromosome known as the ‘social chromosome’. Like many other animals, red fire ants are diploid: their cells have two copies of each chromosome, which can carry two different versions of each gene. The social chromosome is no different, and it comes in two variants, SB and Sb. Each ant can therefore have either two SB chromosomes, leading to a colony with a single queen; or one SB chromosome and one Sb chromosome, leading to a colony with multiple queens. Ants with two copies of the Sb variant die when they are young, so the Sb version is inherited in a similar way to how the Y chromosome is passed on in humans. However, the social chromosome in red fire ants appeared less than one million years ago, making it much younger than the human Y chromosome, which is 180 million years old. This makes the social chromosome a good candidate for examining the early evolution of special chromosome variants that are only inherited. How differences between the SB and the Sb chromosomes are evolving is an open question, however. Perhaps each version of the social chromosome has been optimised through natural selection to one colony type. Another suggestion is that the Sb chromosome has degenerated over time because its genes cannot be ‘reshuffled’ as they would be on normal chromosomes. Martinez-Ruiz et al. compared genetic variants on the SB and Sb chromosomes, along with their expression in different types of ant colonies. The analysis showed that the Sb variant is in fact breaking down because of the lack of gene shuffling. This loss is compensated by intact copies of the same genes found on the SB variant, which explains why ants with the Sb variant can only survive if they also carry the SB version. Only a handful of genes on the social chromosomes appear to have been optimised by natural selection. Therefore Martinez-Ruiz et al. concluded the differences between the two chromosomes that lead to different colony types are collateral effects of Sb’s inability to reshuffle its genes. This work reveals how a special chromosome similar to the Y chromosome in humans evolved. It also shows how multiple complex evolutionary forces can shape a species’ genetic makeup and social forms.
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Affiliation(s)
- Carlos Martinez-Ruiz
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Rodrigo Pracana
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Eckart Stolle
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Carolina Ivon Paris
- Departamento Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160, Ciudad Universitaria, Buenos Aires, Argentina
| | - Richard A Nichols
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Yannick Wurm
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.,Alan Turing Institute, London, United Kingdom
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Sember A, Pappová M, Forman M, Nguyen P, Marec F, Dalíková M, Divišová K, Doležálková-Kaštánková M, Zrzavá M, Sadílek D, Hrubá B, Král J. Patterns of Sex Chromosome Differentiation in Spiders: Insights from Comparative Genomic Hybridisation. Genes (Basel) 2020; 11:E849. [PMID: 32722348 PMCID: PMC7466014 DOI: 10.3390/genes11080849] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 01/21/2023] Open
Abstract
Spiders are an intriguing model to analyse sex chromosome evolution because of their peculiar multiple X chromosome systems. Y chromosomes were considered rare in this group, arising after neo-sex chromosome formation by X chromosome-autosome rearrangements. However, recent findings suggest that Y chromosomes are more common in spiders than previously thought. Besides neo-sex chromosomes, they are also involved in the ancient X1X2Y system of haplogyne spiders, whose origin is unknown. Furthermore, spiders seem to exhibit obligatorily one or two pairs of cryptic homomorphic XY chromosomes (further cryptic sex chromosome pairs, CSCPs), which could represent the ancestral spider sex chromosomes. Here, we analyse the molecular differentiation of particular types of spider Y chromosomes in a representative set of ten species by comparative genomic hybridisation (CGH). We found a high Y chromosome differentiation in haplogyne species with X1X2Y system except for Loxosceles spp. CSCP chromosomes exhibited generally low differentiation. Possible mechanisms and factors behind the observed patterns are discussed. The presence of autosomal regions marked predominantly or exclusively with the male or female probe was also recorded. We attribute this pattern to intraspecific variability in the copy number and distribution of certain repetitive DNAs in spider genomes, pointing thus to the limits of CGH in this arachnid group. In addition, we confirmed nonrandom association of chromosomes belonging to particular CSCPs at spermatogonial mitosis and spermatocyte meiosis and their association with multiple Xs throughout meiosis. Taken together, our data suggest diverse evolutionary pathways of molecular differentiation in different types of spider Y chromosomes.
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Affiliation(s)
- Alexandr Sember
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 277 21 Liběchov, Czech Republic;
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Michaela Pappová
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Martin Forman
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Petr Nguyen
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic; (P.N.); (M.D.); (M.Z.)
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic;
| | - František Marec
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic;
| | - Martina Dalíková
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic; (P.N.); (M.D.); (M.Z.)
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic;
| | - Klára Divišová
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Marie Doležálková-Kaštánková
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Rumburská 89, 277 21 Liběchov, Czech Republic;
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Magda Zrzavá
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic; (P.N.); (M.D.); (M.Z.)
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Branišovská 31, 370 05 České Budějovice, Czech Republic;
| | - David Sadílek
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 44 Prague, Czech Republic
| | - Barbora Hrubá
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
| | - Jiří Král
- Laboratory of Arachnid Cytogenetics, Department of Genetics and Microbiology, Faculty of Science, Charles University, Viničná 5, 128 44 Prague, Czech Republic; (M.P.); (M.F.); (K.D.); (D.S.); (B.H.); (J.K.)
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Fruchard C, Badouin H, Latrasse D, Devani RS, Muyle A, Rhoné B, Renner SS, Banerjee AK, Bendahmane A, Marais GAB. Evidence for Dosage Compensation in Coccinia grandis, a Plant with a Highly Heteromorphic XY System. Genes (Basel) 2020; 11:E787. [PMID: 32668777 PMCID: PMC7397054 DOI: 10.3390/genes11070787] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/01/2020] [Accepted: 07/08/2020] [Indexed: 01/17/2023] Open
Abstract
About 15,000 angiosperms are dioecious, but the mechanisms of sex determination in plants remain poorly understood. In particular, how Y chromosomes evolve and degenerate, and whether dosage compensation evolves as a response, are matters of debate. Here, we focus on Coccinia grandis, a dioecious cucurbit with the highest level of X/Y heteromorphy recorded so far. We identified sex-linked genes using RNA sequences from a cross and a model-based method termed SEX-DETector. Parents and F1 individuals were genotyped, and the transmission patterns of SNPs were then analyzed. In the >1300 sex-linked genes studied, maximum X-Y divergence was 0.13-0.17, and substantial Y degeneration is implied by an average Y/X expression ratio of 0.63 and an inferred gene loss on the Y of ~40%. We also found reduced Y gene expression being compensated by elevated expression of corresponding genes on the X and an excess of sex-biased genes on the sex chromosomes. Molecular evolution of sex-linked genes in C. grandis is thus comparable to that in Silene latifolia, another dioecious plant with a strongly heteromorphic XY system, and cucurbits are the fourth plant family in which dosage compensation is described, suggesting it might be common in plants.
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Affiliation(s)
- Cécile Fruchard
- Laboratoire de Biométrie et Biologie Evolutive (LBBE), UMR5558, Université Lyon 1, 69622 Villeurbanne, France; (C.F.); (H.B.); (B.R.)
| | - Hélène Badouin
- Laboratoire de Biométrie et Biologie Evolutive (LBBE), UMR5558, Université Lyon 1, 69622 Villeurbanne, France; (C.F.); (H.B.); (B.R.)
| | - David Latrasse
- Institute of Plant Sciences Paris Saclay (IPS2), University of Paris Saclay, 91405 Orsay, France; (D.L.); (R.S.D.); (A.B.)
| | - Ravi S. Devani
- Institute of Plant Sciences Paris Saclay (IPS2), University of Paris Saclay, 91405 Orsay, France; (D.L.); (R.S.D.); (A.B.)
- Biology Division, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India;
| | - Aline Muyle
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, USA;
| | - Bénédicte Rhoné
- Laboratoire de Biométrie et Biologie Evolutive (LBBE), UMR5558, Université Lyon 1, 69622 Villeurbanne, France; (C.F.); (H.B.); (B.R.)
- Institut de Recherche pour le Développement (IRD), Université Montpellier, DIADE, F-34394 Montpellier, France
| | - Susanne S. Renner
- Systematic Botany and Mycology, University of Munich (LMU), Menzinger Str. 67, 80638 Munich, Germany;
| | - Anjan K. Banerjee
- Biology Division, Indian Institute of Science Education and Research (IISER), Pune 411008, Maharashtra, India;
| | - Abdelhafid Bendahmane
- Institute of Plant Sciences Paris Saclay (IPS2), University of Paris Saclay, 91405 Orsay, France; (D.L.); (R.S.D.); (A.B.)
| | - Gabriel A. B. Marais
- Laboratoire de Biométrie et Biologie Evolutive (LBBE), UMR5558, Université Lyon 1, 69622 Villeurbanne, France; (C.F.); (H.B.); (B.R.)
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Meisel RP. Evolution of Sex Determination and Sex Chromosomes: A Novel Alternative Paradigm. Bioessays 2020; 42:e1900212. [DOI: 10.1002/bies.201900212] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 05/11/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Richard P. Meisel
- Department of Biology and Biochemistry University of Houston 3455 Cullen Blvd Houston TX 77204‐5001 USA
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Lenormand T, Fyon F, Sun E, Roze D. Sex Chromosome Degeneration by Regulatory Evolution. Curr Biol 2020; 30:3001-3006.e5. [PMID: 32559446 DOI: 10.1016/j.cub.2020.05.052] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/07/2020] [Accepted: 05/14/2020] [Indexed: 12/31/2022]
Abstract
In many species, the Y (or W) sex chromosome is degenerate. Current theory proposes that this degeneration follows the arrest of recombination and results from the accumulation of deleterious mutations due to selective interference-the inefficacy of natural selection on non-recombining genomic regions. This theory requires very few assumptions, but it does not robustly predict fast erosion of the Y (or W) in large populations or the stepwise degeneration of several small non-recombining strata. We propose a new mechanism for Y/W erosion that works over faster timescales, in large populations, and for small non-recombining regions (down to a single sex-linked gene). The mechanism is based on the instability and divergence of cis-regulatory sequences in non-recombining genome regions, which become selectively haploidized to mask deleterious mutations on coding sequences. This haploidization is asymmetric, because cis-regulators on the X cannot be silenced (otherwise there would be no expression in females). This process causes rapid Y/W degeneration and simultaneous evolution of dosage compensation, provided that autosomal trans-regulatory sequences with sex-limited effects are available to compensate for cis-regulatory divergence. Although this "degeneration by regulatory evolution" does not require selective interference, both processes may act in concert to further accelerate Y degeneration.
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Affiliation(s)
- Thomas Lenormand
- CEFE, Univ Montpellier, CNRS, Univ Paul Valéry Montpellier 3, EPHE, IRD, Montpellier 34293, France; Radcliffe Institute, Harvard University, Cambridge, MA 02138, USA.
| | - Frederic Fyon
- CEFE, Univ Montpellier, CNRS, Univ Paul Valéry Montpellier 3, EPHE, IRD, Montpellier 34293, France
| | - Eric Sun
- Radcliffe Institute, Harvard University, Cambridge, MA 02138, USA
| | - Denis Roze
- CNRS, UMI 3614, Roscoff 29680, France; Sorbonne Université, Station Biologique de Roscoff, France
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Turtle Insights into the Evolution of the Reptilian Karyotype and the Genomic Architecture of Sex Determination. Genes (Basel) 2020; 11:genes11040416. [PMID: 32290488 PMCID: PMC7231036 DOI: 10.3390/genes11040416] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/06/2020] [Accepted: 04/08/2020] [Indexed: 01/01/2023] Open
Abstract
Sex chromosome evolution remains an evolutionary puzzle despite its importance in understanding sexual development and genome evolution. The seemingly random distribution of sex-determining systems in reptiles offers a unique opportunity to study sex chromosome evolution not afforded by mammals or birds. These reptilian systems derive from multiple transitions in sex determination, some independent, some convergent, that lead to the birth and death of sex chromosomes in various lineages. Here we focus on turtles, an emerging model group with growing genomic resources. We review karyotypic changes that accompanied the evolution of chromosomal systems of genotypic sex determination (GSD) in chelonians from systems under the control of environmental temperature (TSD). These transitions gave rise to 31 GSD species identified thus far (out of 101 turtles with known sex determination), 27 with a characterized sex chromosome system (13 of those karyotypically). These sex chromosomes are varied in terms of the ancestral autosome they co-opted and thus in their homology, as well as in their size (some are macro-, some are micro-chromosomes), heterogamety (some are XX/XY, some ZZ/ZW), dimorphism (some are virtually homomorphic, some heteromorphic with larger-X, larger W, or smaller-Y), age (the oldest system could be ~195 My old and the youngest < 25 My old). Combined, all data indicate that turtles follow some tenets of classic theoretical models of sex chromosome evolution while countering others. Finally, although the study of dosage compensation and molecular divergence of turtle sex chromosomes has lagged behind research on other aspects of their evolution, this gap is rapidly decreasing with the acceleration of ongoing research and growing genomic resources in this group.
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Ma WJ, Carpentier F, Giraud T, Hood ME. Differential Gene Expression between Fungal Mating Types Is Associated with Sequence Degeneration. Genome Biol Evol 2020; 12:243-258. [PMID: 32058544 PMCID: PMC7150583 DOI: 10.1093/gbe/evaa028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2020] [Indexed: 12/13/2022] Open
Abstract
Degenerative mutations in non-recombining regions, such as in sex chromosomes, may lead to differential expression between alleles if mutations occur stochastically in one or the other allele. Reduced allelic expression due to degeneration has indeed been suggested to occur in various sex-chromosome systems. However, whether an association occurs between specific signatures of degeneration and differential expression between alleles has not been extensively tested, and sexual antagonism can also cause differential expression on sex chromosomes. The anther-smut fungus Microbotryum lychnidis-dioicae is ideal for testing associations between specific degenerative signatures and differential expression because 1) there are multiple evolutionary strata on the mating-type chromosomes, reflecting successive recombination suppression linked to mating-type loci; 2) separate haploid cultures of opposite mating types help identify differential expression between alleles; and 3) there is no sexual antagonism as a confounding factor accounting for differential expression. We found that differentially expressed genes were enriched in the four oldest evolutionary strata compared with other genomic compartments, and that, within compartments, several signatures of sequence degeneration were greater for differentially expressed than non-differentially expressed genes. Two particular degenerative signatures were significantly associated with lower expression levels within differentially expressed allele pairs: upstream insertion of transposable elements and mutations truncating the protein length. Other degenerative mutations associated with differential expression included nonsynonymous substitutions and altered intron or GC content. The association between differential expression and allele degeneration is relevant for a broad range of taxa where mating compatibility or sex is determined by genes located in large regions where recombination is suppressed.
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Affiliation(s)
- Wen-Juan Ma
- Department of Biology, Amherst College, Amherst, MA
| | - Fantin Carpentier
- Ecologie Systematique et Evolution, Université Paris-Saclay, CNRS, AgroParisTech, Orsay, France
| | - Tatiana Giraud
- Ecologie Systematique et Evolution, Université Paris-Saclay, CNRS, AgroParisTech, Orsay, France
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