1
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Marin-Recinos MF, Pucker B. Genetic factors explaining anthocyanin pigmentation differences. BMC PLANT BIOLOGY 2024; 24:627. [PMID: 38961369 PMCID: PMC11221117 DOI: 10.1186/s12870-024-05316-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 06/20/2024] [Indexed: 07/05/2024]
Abstract
BACKGROUND Anthocyanins are important contributors to coloration across a wide phylogenetic range of plants. Biological functions of anthocyanins span from reproduction to protection against biotic and abiotic stressors. Owing to a clearly visible phenotype of mutants, the anthocyanin biosynthesis and its sophisticated regulation have been studied in numerous plant species. Genes encoding the anthocyanin biosynthesis enzymes are regulated by a transcription factor complex comprising MYB, bHLH and WD40 proteins. RESULTS A systematic comparison of anthocyanin-pigmented vs. non-pigmented varieties was performed within numerous plant species covering the taxonomic diversity of flowering plants. The literature was screened for cases in which genetic factors causing anthocyanin loss were reported. Additionally, transcriptomic data sets from four previous studies were reanalyzed to determine the genes possibly responsible for color variation based on their expression pattern. The contribution of different structural and regulatory genes to the intraspecific pigmentation differences was quantified. Differences concerning transcription factors are by far the most frequent explanation for pigmentation differences observed between two varieties of the same species. Among the transcription factors in the analyzed cases, MYB genes are significantly more prone to account for pigmentation differences compared to bHLH or WD40 genes. Among the structural genes, DFR genes are most often associated with anthocyanin loss. CONCLUSIONS These findings support previous assumptions about the susceptibility of transcriptional regulation to evolutionary changes and its importance for the evolution of novel coloration phenotypes. Our findings underline the particular significance of MYBs and their apparent prevalent role in the specificity of the MBW complex.
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Affiliation(s)
- Maria F Marin-Recinos
- Plant Biotechnology and Bioinformatics, Institute of Plant Biology and BRICS, TU Braunschweig, Braunschweig, Germany
| | - Boas Pucker
- Plant Biotechnology and Bioinformatics, Institute of Plant Biology and BRICS, TU Braunschweig, Braunschweig, Germany.
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2
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Majane AC, Cridland JM, Blair LK, Begun DJ. Evolution and genetics of accessory gland transcriptome divergence between Drosophila melanogaster and D. simulans. Genetics 2024; 227:iyae039. [PMID: 38518250 PMCID: PMC11151936 DOI: 10.1093/genetics/iyae039] [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: 08/27/2023] [Revised: 08/27/2023] [Accepted: 02/15/2024] [Indexed: 03/24/2024] Open
Abstract
Studies of allele-specific expression in interspecific hybrids have provided important insights into gene-regulatory divergence and hybrid incompatibilities. Many such investigations in Drosophila have used transcriptome data from complex mixtures of many tissues or from gonads, however, regulatory divergence may vary widely among species, sexes, and tissues. Thus, we lack sufficiently broad sampling to be confident about the general biological principles of regulatory divergence. Here, we seek to fill some of these gaps in the literature by characterizing regulatory evolution and hybrid misexpression in a somatic male sex organ, the accessory gland, in F1 hybrids between Drosophila melanogaster and D. simulans. The accessory gland produces seminal fluid proteins, which play an important role in male and female fertility and may be subject to adaptive divergence due to male-male or male-female interactions. We find that trans differences are relatively more abundant than cis, in contrast to most of the interspecific hybrid literature, though large effect-size trans differences are rare. Seminal fluid protein genes have significantly elevated levels of expression divergence and tend to be regulated through both cis and trans divergence. We find limited misexpression (over- or underexpression relative to both parents) in this organ compared to most other Drosophila studies. As in previous studies, male-biased genes are overrepresented among misexpressed genes and are much more likely to be underexpressed. ATAC-Seq data show that chromatin accessibility is correlated with expression differences among species and hybrid allele-specific expression. This work identifies unique regulatory evolution and hybrid misexpression properties of the accessory gland and suggests the importance of tissue-specific allele-specific expression studies.
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Affiliation(s)
- Alex C Majane
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Julie M Cridland
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - Logan K Blair
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
| | - David J Begun
- Department of Evolution and Ecology, University of California, Davis, CA 95616, USA
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3
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Lee U, Li C, Langer CB, Svetec N, Zhao L. Comparative Single Cell Analysis of Transcriptional Bursting Reveals the Role of Genome Organization on de novo Transcript Origination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591771. [PMID: 38746255 PMCID: PMC11092510 DOI: 10.1101/2024.04.29.591771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Spermatogenesis is a key developmental process underlying the origination of newly evolved genes. However, rapid cell type-specific transcriptomic divergence of the Drosophila germline has posed a significant technical barrier for comparative single-cell RNA-sequencing (scRNA-Seq) studies. By quantifying a surprisingly strong correlation between species-and cell type-specific divergence in three closely related Drosophila species, we apply a simple statistical procedure to identify a core set of 198 genes that are highly predictive of cell type identity while remaining robust to species-specific differences that span over 25-30 million years of evolution. We then utilize cell type classifications based on the 198-gene set to show how transcriptional divergence in cell type increases throughout spermatogenic developmental time, contrasting with traditional hourglass models of whole-organism development. With these cross-species cell type classifications, we then investigate the influence of genome organization on the molecular evolution of spermatogenesis vis-a-vis transcriptional bursting. We first demonstrate how mechanistic control of pre-meiotic transcription is achieved by altering transcriptional burst size while post-meiotic control is exerted via altered bursting frequency. We then report how global differences in autosomal vs. X chromosomal transcription likely arise in a developmental stage preceding full testis organogenesis by showing evolutionarily conserved decreases in X-linked transcription bursting kinetics in all examined somatic and germline cell types. Finally, we provide evidence supporting the cultivator model of de novo gene origination by demonstrating how the appearance of newly evolved testis-specific transcripts potentially provides short-range regulation of the transcriptional bursting properties of neighboring genes during key stages of spermatogenesis.
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4
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Campelo dos Santos AL, DeGiorgio M, Assis R. Predicting evolutionary targets and parameters of gene deletion from expression data. BIOINFORMATICS ADVANCES 2024; 4:vbae002. [PMID: 38282974 PMCID: PMC10812876 DOI: 10.1093/bioadv/vbae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 12/08/2023] [Accepted: 01/04/2024] [Indexed: 01/30/2024]
Abstract
Motivation Gene deletion is traditionally thought of as a nonadaptive process that removes functional redundancy from genomes, such that it generally receives less attention than duplication in evolutionary turnover studies. Yet, mounting evidence suggests that deletion may promote adaptation via the "less-is-more" evolutionary hypothesis, as it often targets genes harboring unique sequences, expression profiles, and molecular functions. Hence, predicting the relative prevalence of redundant and unique functions among genes targeted by deletion, as well as the parameters underlying their evolution, can shed light on the role of gene deletion in adaptation. Results Here, we present CLOUDe, a suite of machine learning methods for predicting evolutionary targets of gene deletion events from expression data. Specifically, CLOUDe models expression evolution as an Ornstein-Uhlenbeck process, and uses multi-layer neural network, extreme gradient boosting, random forest, and support vector machine architectures to predict whether deleted genes are "redundant" or "unique", as well as several parameters underlying their evolution. We show that CLOUDe boasts high power and accuracy in differentiating between classes, and high accuracy and precision in estimating evolutionary parameters, with optimal performance achieved by its neural network architecture. Application of CLOUDe to empirical data from Drosophila suggests that deletion primarily targets genes with unique functions, with further analysis showing these functions to be enriched for protein deubiquitination. Thus, CLOUDe represents a key advance in learning about the role of gene deletion in functional evolution and adaptation. Availability and implementation CLOUDe is freely available on GitHub (https://github.com/anddssan/CLOUDe).
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Affiliation(s)
- Andre Luiz Campelo dos Santos
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Michael DeGiorgio
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, United States
| | - Raquel Assis
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431, United States
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FL 33431, United States
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5
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Bhaskara GB, Haque T, Bonnette JE, Napier JD, Bauer D, Schmutz J, Juenger TE. Evolutionary Analyses of Gene Expression Divergence in Panicum hallii: Exploring Constitutive and Plastic Responses Using Reciprocal Transplants. Mol Biol Evol 2023; 40:msad210. [PMID: 37738160 PMCID: PMC10556983 DOI: 10.1093/molbev/msad210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/27/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023] Open
Abstract
The evolution of gene expression is thought to be an important mechanism of local adaptation and ecological speciation. Gene expression divergence occurs through the evolution of cis- polymorphisms and through more widespread effects driven by trans-regulatory factors. Here, we explore expression and sequence divergence in a large sample of Panicum hallii accessions encompassing the species range using a reciprocal transplantation experiment. We observed widespread genotype and transplant site drivers of expression divergence, with a limited number of genes exhibiting genotype-by-site interactions. We used a modified FST-QST outlier approach (QPC analysis) to detect local adaptation. We identified 514 genes with constitutive expression divergence above and beyond the levels expected under neutral processes. However, no plastic expression responses met our multiple testing correction as QPC outliers. Constitutive QPC outlier genes were involved in a number of developmental processes and responses to abiotic environments. Leveraging earlier expression quantitative trait loci results, we found a strong enrichment of expression divergence, including for QPC outliers, in genes previously identified with cis and cis-environment interactions but found no patterns related to trans-factors. Population genetic analyses detected elevated sequence divergence of promoters and coding sequence of constitutive expression outliers but little evidence for positive selection on these proteins. Our results are consistent with a hypothesis of cis-regulatory divergence as a primary driver of expression divergence in P. hallii.
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Affiliation(s)
| | - Taslima Haque
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, USA
| | - Jason E Bonnette
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, USA
| | - Joseph D Napier
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, USA
| | - Diane Bauer
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jeremy Schmutz
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Thomas E Juenger
- Department of Integrative Biology, The University of Texas at Austin, Austin, TX, USA
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6
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Tosto NM, Beasley ER, Wong BBM, Mank JE, Flanagan SP. The roles of sexual selection and sexual conflict in shaping patterns of genome and transcriptome variation. Nat Ecol Evol 2023; 7:981-993. [PMID: 36959239 DOI: 10.1038/s41559-023-02019-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 02/21/2023] [Indexed: 03/25/2023]
Abstract
Sexual dimorphism is one of the most prevalent, and often the most extreme, examples of phenotypic variation within species, and arises primarily from genomic variation that is shared between females and males. Many sexual dimorphisms arise through sex differences in gene expression, and sex-biased expression is one way that a single, shared genome can generate multiple, distinct phenotypes. Although many sexual dimorphisms are expected to result from sexual selection, and many studies have invoked the possible role of sexual selection to explain sex-specific traits, the role of sexual selection in the evolution of sexually dimorphic gene expression remains difficult to differentiate from other forms of sex-specific selection. In this Review, we propose a holistic framework for the study of sex-specific selection and transcriptome evolution. We advocate for a comparative approach, across tissues, developmental stages and species, which incorporates an understanding of the molecular mechanisms, including genomic variation and structure, governing gene expression. Such an approach is expected to yield substantial insights into the evolution of genetic variation and have important applications in a variety of fields, including ecology, evolution and behaviour.
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Affiliation(s)
- Nicole M Tosto
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Emily R Beasley
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Bob B M Wong
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Judith E Mank
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sarah P Flanagan
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
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7
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Piya AA, DeGiorgio M, Assis R. Predicting gene expression divergence between single-copy orthologs in two species. Genome Biol Evol 2023; 15:evad078. [PMID: 37170892 PMCID: PMC10220509 DOI: 10.1093/gbe/evad078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 04/21/2023] [Accepted: 05/02/2023] [Indexed: 05/13/2023] Open
Abstract
Predicting gene expression divergence is integral to understanding the emergence of new biological functions and associated traits. Whereas several sophisticated methods have been developed for this task, their applications are either limited to duplicate genes or require expression data from more than two species. Thus, here we present PiXi, the first machine learning framework for predicting gene expression divergence between single-copy orthologs in two species. PiXi models gene expression evolution as an Ornstein-Uhlenbeck process, and overlays this model with multi-layer neural network, random forest, and support vector machine architectures for making predictions. It outputs the predicted class "conserved" or "diverged" for each pair of orthologs, as well as their predicted expression optima in the two species. We show that PiXi has high power and accuracy in predicting gene expression divergence between single-copy orthologs, as well as high accuracy and precision in estimating their expression optima in the two species, across a wide range of evolutionary scenarios, with the globally best performance achieved by a multi-layer neural network. Moreover, application of our best performing PiXi predictor to empirical gene expression data from single-copy orthologs residing at different loci in two species of Drosophila reveals that approximately 23% underwent expression divergence after positional relocation. Further analysis shows that several of these "diverged" genes are involved in the electron transport chain of the mitochondrial membrane, suggesting that new chromatin environments may impact energy production in Drosophila. Thus, by providing a toolkit for predicting gene expression divergence between single-copy orthologs in two species, PiXi can shed light on the origins of novel phenotypes across diverse biological processes and study systems.
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Affiliation(s)
- Antara Anika Piya
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FloridaUSA
| | - Michael DeGiorgio
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FloridaUSA
| | - Raquel Assis
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FloridaUSA
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FloridaUSA
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8
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Bittner NKJ, Mack KL, Nachman MW. Shared Patterns of Gene Expression and Protein Evolution Associated with Adaptation to Desert Environments in Rodents. Genome Biol Evol 2022; 14:6765154. [PMID: 36268582 PMCID: PMC9648513 DOI: 10.1093/gbe/evac155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2022] [Indexed: 01/18/2023] Open
Abstract
Desert specialization has arisen multiple times across rodents and is often associated with a suite of convergent phenotypes, including modification of the kidneys to mitigate water loss. However, the extent to which phenotypic convergence in desert rodents is mirrored at the molecular level is unknown. Here, we sequenced kidney mRNA and assembled transcriptomes for three pairs of rodent species to search for shared differences in gene expression and amino acid sequence associated with adaptation to deserts. We conducted phylogenetically independent comparisons between a desert specialist and a non-desert relative in three families representing ∼70 million years of evolution. Overall, patterns of gene expression faithfully recapitulated the phylogeny of these six taxa providing a strong evolutionary signal in levels of mRNA abundance. We also found that 8.6% of all genes showed shared patterns of expression divergence between desert and non-desert taxa, much of which likely reflects convergent evolution, and representing more than expected by chance under a model of independent gene evolution. In addition to these shared changes, we observed many species-pair-specific changes in gene expression indicating that instances of adaptation to deserts include a combination of unique and shared changes. Patterns of protein evolution revealed a small number of genes showing evidence of positive selection, the majority of which did not show shared changes in gene expression. Overall, our results suggest that convergent changes in gene regulation play an important role in the complex trait of desert adaptation in rodents.
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Affiliation(s)
- Noëlle K J Bittner
- Department of Integrative Biology and Museum of Vertebrate Zoology, 3101 Valley Life Sciences Building, University of California Berkeley, California 94720
| | - Katya L Mack
- Present address: Department of Biology, Stanford University, CA 94305
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9
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Feitzinger AA, Le A, Thompson A, Haseeb M, Murugesan MK, Tang AM, Lott SE. Natural variation in the maternal and zygotic mRNA complements of the early embryo in Drosophila melanogaster. BMC Genomics 2022; 23:641. [PMID: 36076188 PMCID: PMC9461177 DOI: 10.1186/s12864-022-08839-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 08/10/2022] [Indexed: 11/23/2022] Open
Abstract
Background Maternal gene products supplied to the egg during oogenesis drive the earliest events of development in all metazoans. After the initial stages of embryogenesis, maternal transcripts are degraded as zygotic transcription is activated; this is known as the maternal to zygotic transition (MZT). Recently, it has been shown that the expression of maternal and zygotic transcripts have evolved in the Drosophila genus over the course of 50 million years. However, the extent of natural variation of maternal and zygotic transcripts within a species has yet to be determined. We asked how the maternal and zygotic pools of mRNA vary within and between populations of D. melanogaster. In order to maximize sampling of genetic diversity, African lines of D. melanogaster originating from Zambia as well as DGRP lines originating from North America were chosen for transcriptomic analysis. Results Generally, we find that maternal transcripts are more highly conserved, and zygotic transcripts evolve at a higher rate. We find that there is more within-population variation in transcript abundance than between populations and that expression variation is highest post- MZT between African lines. Conclusions Determining the natural variation of gene expression surrounding the MZT in natural populations of D. melanogaster gives insight into the extent of how a tightly regulated process may vary within a species, the extent of developmental constraint at both stages and on both the maternal and zygotic genomes, and reveals expression changes allowing this species to adapt as it spread across the world. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08839-4.
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Affiliation(s)
- Anna A Feitzinger
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA.
| | - Anthony Le
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - Ammon Thompson
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - Mehnoor Haseeb
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | | | - Austin M Tang
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
| | - Susan E Lott
- Department of Evolution and Ecology, University of California, Davis, CA, 95616, USA
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10
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Patlar B, Civetta A. Seminal fluid gene expression and reproductive fitness in Drosophila melanogaster. BMC Ecol Evol 2022; 22:20. [PMID: 35196983 PMCID: PMC8867848 DOI: 10.1186/s12862-022-01975-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/15/2022] [Indexed: 11/24/2022] Open
Abstract
Background The rapid evolution of seminal fluid proteins (SFPs) has been suggested to be driven by adaptations to postcopulatory sexual selection (e.g. sperm competition). However, we have recently shown that most SFPs evolve rapidly under relaxed selective pressures. Given the role of SFPs in competition for fertilization phenotypes, like the ability to transfer and store sperm and the modulation of female receptivity and ovulation, the prevalence of selectively relaxed SFPs appears as a conundrum. One possible explanation is that selection on SFPs might be relaxed in terms of protein amino acid content, but adjustments of expression are essential for post-mating function. Interestingly, there is a general lack of systematic implementation of gene expression perturbation assays to monitor their effect on phenotypes related to sperm competition. Results We successfully manipulated the expression of 16 SFP encoding genes using tissue-specific knockdowns (KDs) and determined the effect of these genes’ perturbation on three important post-mating phenotypes: female refractoriness to remating, defensive (P1), and offensive (P2) sperm competitive abilities in Drosophila melanogaster. Our analyses show that KDs of tested SFP genes do not affect female refractoriness to remating and P2, however, most gene KDs significantly decreased P1. Moreover, KDs of SFP genes that are selectively constrained in terms of protein-coding sequence evolution have lower P1 than KDs of genes evolving under relaxed selection. Conclusions Our results suggest a more predominant role, than previously acknowledged, of variation in gene expression than coding sequence changes on sperm competitive ability in D. melanogaster. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-022-01975-1.
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Affiliation(s)
- Bahar Patlar
- Department of Biology, University of Winnipeg, Winnipeg, MB, R3B 2E9, Canada
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, Winnipeg, MB, R3B 2E9, Canada.
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11
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Lai WY, Schlötterer C. Evolution of phenotypic variance in response to a novel hot environment. Mol Ecol 2021; 31:934-945. [PMID: 34775658 DOI: 10.1111/mec.16274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 10/21/2021] [Accepted: 11/05/2021] [Indexed: 12/13/2022]
Abstract
Shifts in trait means are widely considered as evidence for adaptive responses, but the impact on phenotypic variance remains largely unexplored. Classic quantitative genetics provides a theoretical framework to predict how selection on phenotypic mean affects the variance. In addition to this indirect effect, it is also possible that the variance of the trait is the direct target of selection, but experimentally characterized cases are rare. Here, we studied gene expression variance of Drosophila simulans males before and after 100 generations of adaptation to a novel hot laboratory environment. In each of the two independently evolved populations, the variance of 125 and 97 genes was significantly reduced. We propose that the drastic loss in environmental complexity from nature to the laboratory may have triggered selection for reduced variance. Our observation that selection could drive changes in the variance of gene expression could have important implications for studies of adaptation processes in natural and experimental populations.
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Affiliation(s)
- Wei-Yun Lai
- Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria.,Vienna Graduate School of Population Genetics, Vetmeduni Vienna, Vienna, Austria
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12
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Scharmann M, Rebelo AG, Pannell JR. High rates of evolution preceded shifts to sex-biased gene expression in Leucadendron, the most sexually dimorphic angiosperms. eLife 2021; 10:e67485. [PMID: 34726596 PMCID: PMC8635981 DOI: 10.7554/elife.67485] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 10/27/2021] [Indexed: 11/21/2022] Open
Abstract
Differences between males and females are usually more subtle in dioecious plants than animals, but strong sexual dimorphism has evolved convergently in the South African Cape plant genus Leucadendron. Such sexual dimorphism in leaf size is expected largely to be due to differential gene expression between the sexes. We compared patterns of gene expression in leaves among 10 Leucadendron species across the genus. Surprisingly, we found no positive association between sexual dimorphism in morphology and the number or the percentage of sex-biased genes (SBGs). Sex bias in most SBGs evolved recently and was species specific. We compared rates of evolutionary change in expression for genes that were sex biased in one species but unbiased in others and found that SBGs evolved faster in expression than unbiased genes. This greater rate of expression evolution of SBGs, also documented in animals, might suggest the possible role of sexual selection in the evolution of gene expression. However, our comparative analysis clearly indicates that the more rapid rate of expression evolution of SBGs predated the origin of bias, and shifts towards bias were depleted in signatures of adaptation. Our results are thus more consistent with the view that sex bias is simply freer to evolve in genes less subject to constraints in expression level.
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Affiliation(s)
- Mathias Scharmann
- Department of Ecology and Evolution, University of LausanneLausanneSwitzerland
| | - Anthony G Rebelo
- Applied Biodiversity Research Division, South African National Biodiversity InstituteCape TownSouth Africa
| | - John R Pannell
- Department of Ecology and Evolution, University of LausanneLausanneSwitzerland
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13
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Jayaswal V, Ndo C, Ma HC, Clifton BD, Pombi M, Cabrera K, Couhet A, Mouline K, Diabaté A, Dabiré R, Ayala D, Ranz JM. Intraspecific Transcriptome Variation and Sex-Biased Expression in Anopheles arabiensis. Genome Biol Evol 2021; 13:6357708. [PMID: 34432020 PMCID: PMC8449828 DOI: 10.1093/gbe/evab199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2021] [Indexed: 01/17/2023] Open
Abstract
The magnitude and functional patterns of intraspecific transcriptional variation in the anophelines, including those of sex-biased genes underlying sex-specific traits relevant for malaria transmission, remain understudied. As a result, how changes in expression levels drive adaptation in these species is poorly understood. We sequenced the female, male, and larval transcriptomes of three populations of Anopheles arabiensis from Burkina Faso. One-third of the genes were differentially expressed between populations, often involving insecticide resistance-related genes in a sample type-specific manner, and with the females showing the largest number of differentially expressed genes. At the genomic level, the X chromosome appears depleted of differentially expressed genes compared with the autosomes, chromosomes harboring inversions do not exhibit evidence for enrichment of such genes, and genes that are top contributors to functional enrichment patterns of population differentiation tend to be clustered in the genome. Further, the magnitude of variation for the sex expression ratio across populations did not substantially differ between male- and female-biased genes, except for some populations in which male-limited expressed genes showed more variation than their female counterparts. In fact, female-biased genes exhibited a larger level of interpopulation variation than male-biased genes, both when assayed in males and females. Beyond uncovering the extensive adaptive potential of transcriptional variation in An. Arabiensis, our findings suggest that the evolutionary rate of changes in expression levels on the X chromosome exceeds that on the autosomes, while pointing to female-biased genes as the most variable component of the An. Arabiensis transcriptome.
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Affiliation(s)
- Vivek Jayaswal
- School of Mathematics and Statistics, The University of Sydney, Sydney, NSW, Australia
| | - Cyrille Ndo
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Hsiu-Ching Ma
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
| | - Bryan D Clifton
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
| | - Marco Pombi
- Dipartimento di Sanità Pubblica e Malattie Infettive, University of Rome "Sapienza", Rome, Italy
| | - Kevin Cabrera
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
| | - Anna Couhet
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, University of Montpellier, CNRS, Montpellier, IRD, France
| | - Karine Mouline
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, University of Montpellier, CNRS, Montpellier, IRD, France
| | - Abdoulaye Diabaté
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Roch Dabiré
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - Diego Ayala
- Unité Mixte de Recherche Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, University of Montpellier, CNRS, Montpellier, IRD, France
| | - José M Ranz
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, USA
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14
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Johnson KM, Jones HR, Casas SM, La Peyre JF, Kelly MW. Transcriptomic signatures of temperature adaptation in the eastern oyster Crassostrea virginica. J Evol Biol 2021; 34:1212-1224. [PMID: 33837581 DOI: 10.1111/jeb.13789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 02/09/2021] [Accepted: 03/18/2021] [Indexed: 12/20/2022]
Abstract
The large geographic distribution of the eastern oyster, Crassostrea virginica, makes it an ideal species to test how populations have adapted to latitudinal gradients in temperature. Despite inhabiting distinct thermal regimes, populations of C. virginica near the species' southern and northern geographic range show no population differences in their physiological response to temperature. In this study, we used comparative transcriptomics to understand how oysters from either end of the species' range maintain enantiostasis across three acclimation temperatures (10, 20, and 30°C). With this approach, we identified genes that were differentially expressed in response to temperature between individuals of C. virginica collected from New Brunswick, Canada and Louisiana, USA. We observed a core set of genes whose expression responded to temperature in both populations, but also an even larger set of genes with expression patterns that were unique to each population. Intriguingly, the genes with population-specific responses to temperature had elevated FST and Ka/Ks ratios compared to the genome-wide average. In contrast, genes showing only a response to temperature were found to only have elevated FST values suggesting that divergent FST may be due to selection on linked regulatory regions rather than positive selection on protein coding regions. Taken together, our results suggest that, despite coarse-scale physiological similarities, natural selection has shaped divergent gene expression responses to temperature in geographically separated populations of this broadly eurythermal marine invertebrate.
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Affiliation(s)
- Kevin M Johnson
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.,Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA, USA.,California Sea Grant, University of California San Diego, La Jolla, CA, USA
| | - Hollis R Jones
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.,Department of Animal Science, University of California, Davis, CA, USA
| | - Sandra M Casas
- School of Animal Sciences, Louisiana State University Ag Center, Baton Rouge, LA, USA
| | - Jerome F La Peyre
- School of Animal Sciences, Louisiana State University Ag Center, Baton Rouge, LA, USA
| | - Morgan W Kelly
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
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15
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Roycroft E, Achmadi A, Callahan CM, Esselstyn JA, Good JM, Moussalli A, Rowe KC. Molecular Evolution of Ecological Specialisation: Genomic Insights from the Diversification of Murine Rodents. Genome Biol Evol 2021; 13:6275684. [PMID: 33988699 PMCID: PMC8258016 DOI: 10.1093/gbe/evab103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2021] [Indexed: 12/15/2022] Open
Abstract
Adaptive radiations are characterized by the diversification and ecological differentiation of species, and replicated cases of this process provide natural experiments for understanding the repeatability and pace of molecular evolution. During adaptive radiation, genes related to ecological specialization may be subject to recurrent positive directional selection. However, it is not clear to what extent patterns of lineage-specific ecological specialization (including phenotypic convergence) are correlated with shared signatures of molecular evolution. To test this, we sequenced whole exomes from a phylogenetically dispersed sample of 38 murine rodent species, a group characterized by multiple, nested adaptive radiations comprising extensive ecological and phenotypic diversity. We found that genes associated with immunity, reproduction, diet, digestion, and taste have been subject to pervasive positive selection during the diversification of murine rodents. We also found a significant correlation between genome-wide positive selection and dietary specialization, with a higher proportion of positively selected codon sites in derived dietary forms (i.e., carnivores and herbivores) than in ancestral forms (i.e., omnivores). Despite striking convergent evolution of skull morphology and dentition in two distantly related worm-eating specialists, we did not detect more genes with shared signatures of positive or relaxed selection than in a nonconvergent species comparison. Although a small number of the genes we detected can be incidentally linked to craniofacial morphology or diet, protein-coding regions are unlikely to be the primary genetic basis of this complex convergent phenotype. Our results suggest a link between positive selection and derived ecological phenotypes, and highlight specific genes and general functional categories that may have played an integral role in the extensive and rapid diversification of murine rodents.
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Affiliation(s)
- Emily Roycroft
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.,Sciences Department, Museums Victoria, Melbourne, Victoria, Australia.,Division of Ecology and Evolution, Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Anang Achmadi
- Museum Zoologicum Bogoriense, Research Center for Biology, Cibinong, Jawa Barat, Indonesia
| | - Colin M Callahan
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA
| | - Jacob A Esselstyn
- Museum of Natural Science, Louisiana State University, Baton Rouge, Louisiana, USA.,Department of Biological Sciences, Louisiana State University, Baton Rouge, Los Angeles, USA
| | - Jeffrey M Good
- Division of Biological Sciences, University of Montana, Missoula, Montana, USA.,Wildlife Biology Program, University of Montana, Missoula, Montana, USA
| | - Adnan Moussalli
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.,Sciences Department, Museums Victoria, Melbourne, Victoria, Australia
| | - Kevin C Rowe
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia.,Sciences Department, Museums Victoria, Melbourne, Victoria, Australia
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16
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DeGiorgio M, Assis R. Learning Retention Mechanisms and Evolutionary Parameters of Duplicate Genes from Their Expression Data. Mol Biol Evol 2021; 38:1209-1224. [PMID: 33045078 PMCID: PMC7947822 DOI: 10.1093/molbev/msaa267] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Learning about the roles that duplicate genes play in the origins of novel phenotypes requires an understanding of how their functions evolve. A previous method for achieving this goal, CDROM, employs gene expression distances as proxies for functional divergence and then classifies the evolutionary mechanisms retaining duplicate genes from comparisons of these distances in a decision tree framework. However, CDROM does not account for stochastic shifts in gene expression or leverage advances in contemporary statistical learning for performing classification, nor is it capable of predicting the parameters driving duplicate gene evolution. Thus, here we develop CLOUD, a multi-layer neural network built on a model of gene expression evolution that can both classify duplicate gene retention mechanisms and predict their underlying evolutionary parameters. We show that not only is the CLOUD classifier substantially more powerful and accurate than CDROM, but that it also yields accurate parameter predictions, enabling a better understanding of the specific forces driving the evolution and long-term retention of duplicate genes. Further, application of the CLOUD classifier and predictor to empirical data from Drosophila recapitulates many previous findings about gene duplication in this lineage, showing that new functions often emerge rapidly and asymmetrically in younger duplicate gene copies, and that functional divergence is driven by strong natural selection. Hence, CLOUD represents a major advancement in classifying retention mechanisms and predicting evolutionary parameters of duplicate genes, thereby highlighting the utility of incorporating sophisticated statistical learning techniques to address long-standing questions about evolution after gene duplication.
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Affiliation(s)
- Michael DeGiorgio
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FL 33431
| | - Raquel Assis
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FL 33431
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17
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Go AC, Civetta A. Hybrid Incompatibilities and Transgressive Gene Expression Between Two Closely Related Subspecies of Drosophila. Front Genet 2020; 11:599292. [PMID: 33362859 PMCID: PMC7758320 DOI: 10.3389/fgene.2020.599292] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/12/2020] [Indexed: 11/13/2022] Open
Abstract
Genome-wide assays of expression between species and their hybrids have identified genes that become either over- or underexpressed relative to the parental species (i.e., transgressive). Transgressive expression in hybrids is of interest because it highlights possible changes in gene regulation linked to hybrid dysfunction. Previous studies in Drosophila that used long-diverged species pairs with complete or nearly complete isolation (i.e., full sterility and partial inviability of hybrids) and high-levels of genome misregulation have found correlations between expression and coding sequence divergence. The work highlighted the possible effects of directional selection driving sequence divergence and transgressive expression. Whether the same is true for taxa at early stages of divergence that have only achieved partial isolation remains untested. Here, we reanalyze previously published genome expression data and available genome sequence reads from a pair of partially isolated subspecies of Drosophila to compare expression and sequence divergence. We find a significant correlation in rates of expression and sequence evolution, but no support for directional selection driving transgressive expression in hybrids. We find that most transgressive genes in hybrids show no differential expression between parental subspecies and used SNP data to explore the role of stabilizing selection through compensatory mutations. We also examine possible misregulation through cascade effects that could be driven by interacting gene networks or co-option of off-target cis-regulatory elements.
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Affiliation(s)
- Alwyn C Go
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
| | - Alberto Civetta
- Department of Biology, The University of Winnipeg, Winnipeg, MB, Canada
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18
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Němcová L, Marková S, Kotlík P. Gene Expression Variation of Candidate Endogenous Control Genes Across Latitudinal Populations of the Bank Vole (Clethrionomys glareolus). Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.562065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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19
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Ponnanna K, DSouza SM, Amruthavalli C, Ramachandra NB. Allopatric sibling species pair Drosophila nasuta nasuta and Drosophila nasuta albomicans exhibit expression divergence in ovarian transcriptomes. Gene 2020; 777:145189. [PMID: 33035618 DOI: 10.1016/j.gene.2020.145189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 08/18/2020] [Accepted: 09/24/2020] [Indexed: 12/01/2022]
Abstract
Drosophila nasuta nasuta and Drosophila nasuta albomicans represent cross fertile members of the immigrans species group of Drosophila with an allopatric mode of distribution exhibiting characteristic novelties. Illumina sequencing technology and de novo transcriptome assembling strategies were used for the current study. The analysis revealed 8% of the transcriptome to be differentially expressed between the ovaries of these two species, of which 9% was related to female reproduction. The majority of the differentially expressed genes were enriched for genetic information processing pathways, biosynthesis, and metabolism-related pathways. SNPs in D. n. albomicans transcriptome was double in number than in D. n. nasuta and only 5% of these SNPs were fixed. Ka/Ks ratios indicated the lineages were under strong purifying selection. The genes which are differentially expressed are evolving at a similar rate as that of genes with conserved expression. Thus, the current findings provide useful insights on the expression dynamics during incipient species divergence of D. n. nasuta and D. n. albomicans since their divergence time of ~ 0.5 million years.
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Affiliation(s)
- Koushik Ponnanna
- Department of Studies in Genetics & Genomics, University of Mysore, Mysuru, KA, India.
| | - Stafny M DSouza
- Department of Studies in Genetics & Genomics, University of Mysore, Mysuru, KA, India.
| | - C Amruthavalli
- Department of Studies in Genetics & Genomics, University of Mysore, Mysuru, KA, India
| | - Nallur B Ramachandra
- Department of Studies in Genetics & Genomics, University of Mysore, Mysuru, KA, India.
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20
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Abstract
It has long been acknowledged that changes in the regulation of gene expression may account for major organismal differences. However, we still do not fully understand how changes in gene expression evolve and how do such changes influence organisms' differences. We are even less aware of the impact such changes might have in restricting gene flow between species. Here, we focus on studies of gene expression and speciation in the Drosophila model. We review studies that have identified gene interactions in post-mating reproductive isolation and speciation, particularly those that modulate male gene expression. We also address studies that have experimentally manipulated changes in gene expression to test their effect in post-mating reproductive isolation. We highlight the need for a more in-depth analysis of the role of selection causing disrupted gene expression of such candidate genes in sterile/inviable hybrids. Moreover, we discuss the relevance to incorporate more routinely assays that simultaneously evaluate the potential effects of environmental factors and genetic background in modulating plastic responses in male genes and their potential role in speciation.
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Affiliation(s)
- Bahar Patlar
- Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada.,Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - Alberto Civetta
- Department of Biology, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
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21
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Khodursky S, Svetec N, Durkin SM, Zhao L. The evolution of sex-biased gene expression in the Drosophila brain. Genome Res 2020; 30:874-884. [PMID: 32554780 PMCID: PMC7370887 DOI: 10.1101/gr.259069.119] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 06/16/2020] [Indexed: 01/08/2023]
Abstract
Genes with sex-biased expression in Drosophila are thought to underlie sexually dimorphic phenotypes and have been shown to possess unique evolutionary properties. However, the forces and constraints governing the evolution of sex-biased genes in the somatic tissues of Drosophila are largely unknown. By using population-scale RNA sequencing data, we show that sex-biased genes in the Drosophila brain are highly enriched on the X Chromosome and that most are biased in a species-specific manner. We show that X-linked male-biased genes, and to a lesser extent female-biased genes, are enriched for signatures of directional selection at the gene expression level. By examining the evolutionary properties of gene-flanking regions on the X Chromosome, we find evidence that adaptive cis-regulatory changes are more likely to drive the expression evolution of X-linked male-biased genes than other X-linked genes. Finally, we examine whether constraint owing to broad expression across multiple tissues and genetic constraint owing to the largely shared male and female genomes could be responsible for the observed patterns of gene expression evolution. We find that expression breadth does not constrain the directional evolution of gene expression in the brain. Additionally, we find that the shared genome between males and females imposes a substantial constraint on the expression evolution of sex-biased genes. Overall, these results significantly advance our understanding of the patterns and forces shaping the evolution of sexual dimorphism in the Drosophila brain.
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Affiliation(s)
- Samuel Khodursky
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, New York 10065, USA
| | - Nicolas Svetec
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, New York 10065, USA
| | - Sylvia M Durkin
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, New York 10065, USA
| | - Li Zhao
- Laboratory of Evolutionary Genetics and Genomics, The Rockefeller University, New York, New York 10065, USA
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22
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Lian S, Zhou Y, Liu Z, Gong A, Cheng L. The differential expression patterns of paralogs in response to stresses indicate expression and sequence divergences. BMC PLANT BIOLOGY 2020; 20:277. [PMID: 32546126 PMCID: PMC7298774 DOI: 10.1186/s12870-020-02460-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 05/24/2020] [Indexed: 05/22/2023]
Abstract
BACKGROUND Theoretically, paralogous genes generated through whole genome duplications should share identical expression levels due to their identical sequences and chromatin environments. However, functional divergences and expression differences have arisen due to selective pressures throughout evolution. A comprehensive investigation of the expression patterns of paralogous gene pairs in response to various stresses and a study of correlations between the expression levels and sequence divergences of the paralogs are needed. RESULTS In this study, we analyzed the expression patterns of paralogous genes under different types of stress and investigated the correlations between the expression levels and sequence divergences of the paralogs. We analyzed the differential expression patterns of the paralogs under four different types of stress (drought, cold, infection, and herbivory) and classified them into three main types according to their expression patterns. We then further analyzed the differential expression patterns under various degrees of stress and constructed corresponding co-expression networks of differentially expressed paralogs and transcription factors. Finally, we investigated the correlations between the expression levels and sequence divergences of the paralogs and identified positive correlations between expression level and sequence divergence. With regard to sequence divergence, we identified correlations between selective pressures and phylogenetic relationships. CONCLUSIONS These results shed light on differential expression patterns of paralogs in response to environmental stresses and are helpful for understanding the relationships between expression levels and sequences divergences.
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Affiliation(s)
- Shuaibin Lian
- College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, China
| | - Yongjie Zhou
- College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, China
| | - Zixiao Liu
- College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang, China
| | - Andong Gong
- College of Life Sciences, Xinyang Normal University, Xinyang, China
| | - Lin Cheng
- College of Life Sciences, Xinyang Normal University, Xinyang, China
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23
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Wang YJ, Wang HL, Wang XW, Liu SS. Evolutionary Patterns of Sex-Biased Genes in Three Species of Haplodiploid Insects. INSECTS 2020; 11:insects11060326. [PMID: 32466547 PMCID: PMC7349267 DOI: 10.3390/insects11060326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 06/11/2023]
Abstract
Females and males often differ obviously in morphology and behavior, and the differences between sexes are the result of natural selection and/or sexual selection. To a great extent, the differences between the two sexes are the result of differential gene expression. In haplodiploid insects, this phenomenon is obvious, since males develop from unfertilized zygotes and females develop from fertilized zygotes. Whiteflies of the Bemisia tabaci species complex are typical haplodiploid insects, and some species of this complex are important pests of many crops worldwide. Here, we report the transcriptome profiles of males and females in three species of this whitefly complex. Between-species comparisons revealed that non-sex-biased genes display higher variation than male-biased or female-biased genes. Sex-biased genes evolve at a slow rate in protein coding sequences and gene expression and have a pattern of evolution that differs from those of social haplodiploid insects and diploid animals. Genes with high evolutionary rates are more related to non-sex-biased traits-such as nutrition, immune system, and detoxification-than to sex-biased traits, indicating that the evolution of protein coding sequences and gene expression has been mainly driven by non-sex-biased traits.
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24
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Jiang X, Assis R. Population-Specific Genetic and Expression Differentiation in Europeans. Genome Biol Evol 2020; 12:358-369. [PMID: 32365201 PMCID: PMC7197493 DOI: 10.1093/gbe/evaa021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2020] [Indexed: 12/14/2022] Open
Abstract
Much of the enormous phenotypic variation observed across human populations is thought to have arisen from events experienced as our ancestors peopled different regions of the world. However, little is known about the genes involved in these population-specific adaptations. Here, we explore this problem by simultaneously examining population-specific genetic and expression differentiation in four human populations. In particular, we derive a branch-based estimator of population-specific differentiation in four populations, and apply this statistic to single-nucleotide polymorphism and RNA-seq data from Italian, British, Finish, and Yoruban populations. As expected, genome-wide estimates of genetic and expression differentiation each independently recapitulate the known relationships among these four human populations, highlighting the utility of our statistic for identifying putative targets of population-specific adaptations. Moreover, genes with large copy number variations display elevated levels of population-specific genetic and expression differentiation, consistent with the hypothesis that gene duplication and deletion events are key reservoirs of adaptive variation. Further, many top-scoring genes are well-known targets of adaptation in Europeans, including those involved in lactase persistence and vitamin D absorption, and a handful of novel candidates represent promising avenues for future research. Together, these analyses reveal that our statistic can aid in uncovering genes involved in population-specific genetic and expression differentiation, and that such genes often play important roles in a diversity of adaptive and disease-related phenotypes in humans.
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Affiliation(s)
- Xueyuan Jiang
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
| | - Raquel Assis
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802
- Department of Biology, Pennsylvania State University, University Park, PA 16802
- Department of Computer and Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL 33431
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FL 33431
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25
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Mucaki EJ, Shirley BC, Rogan PK. Expression Changes Confirm Genomic Variants Predicted to Result in Allele-Specific, Alternative mRNA Splicing. Front Genet 2020; 11:109. [PMID: 32211018 PMCID: PMC7066660 DOI: 10.3389/fgene.2020.00109] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022] Open
Abstract
Splice isoform structure and abundance can be affected by either noncoding or masquerading coding variants that alter the structure or abundance of transcripts. When these variants are common in the population, these nonconstitutive transcripts are sufficiently frequent so as to resemble naturally occurring, alternative mRNA splicing. Prediction of the effects of such variants has been shown to be accurate using information theory-based methods. Single nucleotide polymorphisms (SNPs) predicted to significantly alter natural and/or cryptic splice site strength were shown to affect gene expression. Splicing changes for known SNP genotypes were confirmed in HapMap lymphoblastoid cell lines with gene expression microarrays and custom designed q-RT-PCR or TaqMan assays. The majority of these SNPs (15 of 22) as well as an independent set of 24 variants were then subjected to RNAseq analysis using the ValidSpliceMut web beacon (http://validsplicemut.cytognomix.com), which is based on data from the Cancer Genome Atlas and International Cancer Genome Consortium. SNPs from different genes analyzed with gene expression microarray and q-RT-PCR exhibited significant changes in affected splice site use. Thirteen SNPs directly affected exon inclusion and 10 altered cryptic site use. Homozygous SNP genotypes resulting in stronger splice sites exhibited higher levels of processed mRNA than alleles associated with weaker sites. Four SNPs exhibited variable expression among individuals with the same genotypes, masking statistically significant expression differences between alleles. Genome-wide information theory and expression analyses (RNAseq) in tumor exomes and genomes confirmed splicing effects for 7 of the HapMap SNP and 14 SNPs identified from tumor genomes. q-RT-PCR resolved rare splice isoforms with read abundance too low for statistical significance in ValidSpliceMut. Nevertheless, the web-beacon provides evidence of unanticipated splicing outcomes, for example, intron retention due to compromised recognition of constitutive splice sites. Thus, ValidSpliceMut and q-RT-PCR represent complementary resources for identification of allele-specific, alternative splicing.
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Affiliation(s)
- Eliseos J Mucaki
- Department of Biochemistry, University of Western Ontario, London, ON, Canada
| | | | - Peter K Rogan
- Department of Biochemistry, University of Western Ontario, London, ON, Canada.,CytoGnomix, London, ON, Canada.,Department of Oncology University of Western Ontario, London, ON, Canada.,Department of Computer Science, University of Western Ontario, London, ON, Canada
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26
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Popovic I, Riginos C. Comparative genomics reveals divergent thermal selection in warm‐ and cold‐tolerant marine mussels. Mol Ecol 2020; 29:519-535. [DOI: 10.1111/mec.15339] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Iva Popovic
- School of Biological Sciences University of Queensland St Lucia Qld Australia
| | - Cynthia Riginos
- School of Biological Sciences University of Queensland St Lucia Qld Australia
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27
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Allan CW, Matzkin LM. Genomic analysis of the four ecologically distinct cactus host populations of Drosophila mojavensis. BMC Genomics 2019; 20:732. [PMID: 31606030 PMCID: PMC6790045 DOI: 10.1186/s12864-019-6097-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Relationships between an organism and its environment can be fundamental in the understanding how populations change over time and species arise. Local ecological conditions can shape variation at multiple levels, among these are the evolutionary history and trajectories of coding genes. This study examines the rate of molecular evolution at protein-coding genes throughout the genome in response to host adaptation in the cactophilic Drosophila mojavensis. These insects are intimately associated with cactus necroses, developing as larvae and feeding as adults in these necrotic tissues. Drosophila mojavensis is composed of four isolated populations across the deserts of western North America and each population has adapted to utilize different cacti that are chemically, nutritionally, and structurally distinct. RESULTS High coverage Illumina sequencing was performed on three previously unsequenced populations of D. mojavensis. Genomes were assembled using the previously sequenced genome of D. mojavensis from Santa Catalina Island (USA) as a template. Protein coding genes were aligned across all four populations and rates of protein evolution were determined for all loci using a several approaches. CONCLUSIONS Loci that exhibited elevated rates of molecular evolution tend to be shorter, have fewer exons, low expression, be transcriptionally responsive to cactus host use and have fixed expression differences across the four cactus host populations. Fast evolving genes were involved with metabolism, detoxification, chemosensory reception, reproduction and behavior. Results of this study give insight into the process and the genomic consequences of local ecological adaptation.
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Affiliation(s)
- Carson W Allan
- Department of Biological Sciences, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL, 35899, USA
- Department of Entomology, University of Arizona, 1140 E. South Campus Drive, Tucson, AZ, 85721, USA
| | - Luciano M Matzkin
- Department of Biological Sciences, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL, 35899, USA.
- Department of Entomology, University of Arizona, 1140 E. South Campus Drive, Tucson, AZ, 85721, USA.
- BIO5 Institute, University of Arizona, 1657 East Helen Street, Tucson, AZ, 85721, USA.
- Department of Ecology and Evolutionary Biology, University of Arizona, 1041 E. Lowell St., Tucson, AZ, 85721, USA.
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28
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Bui LT, Ragsdale EJ. Multiple plasticity regulators reveal targets specifying an induced predatory form in nematodes. Mol Biol Evol 2019; 36:2387-2399. [PMID: 31364718 DOI: 10.1093/molbev/msz171] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/19/2019] [Accepted: 07/17/2019] [Indexed: 12/19/2022] Open
Abstract
The ability to translate a single genome into multiple phenotypes, or developmental plasticity, defines how phenotype derives from more than just genes. However, to study the evolutionary targets of plasticity and their evolutionary fates, we need to understand how genetic regulators of plasticity control downstream gene expression. Here, we have identified a transcriptional response specific to polyphenism (i.e., discrete plasticity) in the nematode Pristionchus pacificus. This species produces alternative resource-use morphs - microbivorous and predatory forms, differing in the form of their teeth, a morphological novelty - as influenced by resource availability. Transcriptional profiles common to multiple polyphenism-controlling genes in P. pacificus reveal a suite of environmentally sensitive loci, or ultimate target genes, that make up an induced developmental response. Additionally, in vitro assays show that one polyphenism regulator, the nuclear receptor (NR) NHR-40, physically binds to promoters with putative HNF4⍺ (the NR class including NHR-40) binding sites, suggesting this receptor may directly regulate genes that describe alternative morphs. Among differentially expressed genes were morph-limited genes, highlighting factors with putative "on-off" function in plasticity regulation. Further, predatory morph-biased genes included candidates - namely, all four P. pacificus homologs of Hsp70, which have HNF4⍺ motifs - whose natural variation in expression matches phenotypic differences among P. pacificus wild isolates. In summary, our study links polyphenism regulatory loci to the transcription producing alternative forms of a morphological novelty. Consequently, our findings establish a platform for determining how specific regulators of morph-biased genes may influence selection on plastic phenotypes.
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Affiliation(s)
- Linh T Bui
- Department of Biology, Indiana University, Bloomington, IN
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Wang S, Chen Y. Fine-Tuning the Expression of Duplicate Genes by Translational Regulation in Arabidopsis and Maize. FRONTIERS IN PLANT SCIENCE 2019; 10:534. [PMID: 31156655 PMCID: PMC6530396 DOI: 10.3389/fpls.2019.00534] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/05/2019] [Indexed: 06/01/2023]
Abstract
Plant genomes are extensively shaped by various types of gene duplication. However, in this active area of investigation, the vast majority of studies focus on the sequence and transcription of duplicate genes, leaving open the question of how translational regulation impacts the expression and evolution of duplicate genes. We explored this issue by analyzing the ribo- and mRNA-seq data sets across six tissue types and stress conditions in Arabidopsis thaliana and maize (Zea mays). We dissected the relative contributions of transcriptional and translational regulation to the divergence in the abundance of ribosome footprint (RF) for different types of duplicate genes. We found that the divergence in RF abundance was largely programmed at the transcription level and that translational regulation plays more of a modulatory role. Intriguingly, translational regulation is characterized by its strong directionality, with the divergence in translational efficiency (TE) globally counteracting the divergence in mRNA abundance, indicating partial buffering of the transcriptional divergence between paralogs by translational regulation. Divergence in TE was associated with several sequence features. The faster-evolving copy in a duplicate pair was more likely to show lower RF abundance, which possibly results from relaxed purifying selection compared with its paralog. A considerable proportion of duplicates displayed differential TE across tissue types and stress conditions, most of which were enriched in photosynthesis, energy production, and translation-related processes. Additionally, we constructed a database TDPDG-DB (http://www.plantdupribo.tk), providing an online platform for data exploration. Overall, our study illustrates the roles of translational regulation in fine-tuning duplicate gene expression in plants.
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Affiliation(s)
- Sishuo Wang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Department of Botany, Faculty of Science, The University of British Columbia, Vancouver, BC, Canada
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Youhua Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
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Differences in Effective Ploidy Drive Genome-Wide Endosperm Expression Polarization and Seed Failure in Wild Tomato Hybrids. Genetics 2019; 212:141-152. [PMID: 30902809 DOI: 10.1534/genetics.119.302056] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 03/18/2019] [Indexed: 01/24/2023] Open
Abstract
Parental imbalances in the endosperm leading to impaired development and eventual hybrid seed failure are common causes of postzygotic isolation in flowering plants. Endosperm sensitivity to parental dosage is reflected by canonical phenotypes of "parental excess" in reciprocal interploid crosses. Moreover, parental-excess traits are also evident in many homoploid interspecific crosses, potentially reflecting among-lineage variation in "effective ploidy" driven by endosperm properties. However, the genetic basis of effective ploidy is unknown and genome-wide expression perturbations in parental-excess endosperms from homoploid crosses have yet to be reported. The tomato clade (Solanum section Lycopersicon), encompassing closely related diploids with partial-to-complete hybrid seed failure, provides outstanding opportunities to study these issues. Here, we compared replicated endosperm transcriptomes from six crosses within and among three wild tomato lineages. Strikingly, strongly inviable hybrid crosses displayed conspicuous, asymmetric expression perturbations that mirror previously characterized parental-excess phenotypes. Solanum peruvianum, the species inferred to have evolved higher effective ploidy than the other two, drove expression landscape polarization between maternal and paternal roles. This global expression divergence was mirrored in functionally important gene families such as MADS-box transcription factors and E3 ubiquitin ligases, and revealed differences in cell cycle tuning that match phenotypic differences in developing endosperm and mature seed size between reciprocal crosses. Our work starts to uncover the complex interactions between expression divergence, parental conflict, and hybrid seed failure that likely contributed to plant diversity.
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Vilgalys TP, Rogers J, Jolly CJ, Baboon Genome Analysis, Mukherjee S, Tung J. Evolution of DNA Methylation in Papio Baboons. Mol Biol Evol 2019; 36:527-540. [PMID: 30521003 PMCID: PMC6389319 DOI: 10.1093/molbev/msy227] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Changes in gene regulation have long been thought to play an important role in primate evolution. However, although a number of studies have compared genome-wide gene expression patterns across primate species, fewer have investigated the gene regulatory mechanisms that underlie such patterns, or the relative contribution of drift versus selection. Here, we profiled genome-scale DNA methylation levels in blood samples from five of the six extant species of the baboon genus Papio (4-14 individuals per species). This radiation presents the opportunity to investigate DNA methylation divergence at both shallow and deeper timescales (0.380-1.4 My). In contrast to studies in human populations, but similar to studies in great apes, DNA methylation profiles clearly mirror genetic and geographic structure. Divergence in DNA methylation proceeds fastest in unannotated regions of the genome and slowest in regions of the genome that are likely more constrained at the sequence level (e.g., gene exons). Both heuristic approaches and Ornstein-Uhlenbeck models suggest that DNA methylation levels at a small set of sites have been affected by positive selection, and that this class is enriched in functionally relevant contexts, including promoters, enhancers, and CpG islands. Our results thus indicate that the rate and distribution of DNA methylation changes across the genome largely mirror genetic structure. However, at some CpG sites, DNA methylation levels themselves may have been a target of positive selection, pointing to loci that could be important in connecting sequence variation to fitness-related traits.
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Affiliation(s)
- Tauras P Vilgalys
- Department of Evolutionary Anthropology, Duke University, Durham, NC
| | - Jeffrey Rogers
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Clifford J Jolly
- Department of Anthropology, New York University, New York, NY
- Center for the Study of Human Origins, New York University, New York, NY
- New York Consortium for Evolutionary Primatology, New York, NY
| | | | - Sayan Mukherjee
- Department of Statistical Science, Duke University, Durham, NC
- Department of Mathematics, Duke University, Durham, NC
- Department of Computer Science, Duke University, Durham, NC
| | - Jenny Tung
- Department of Evolutionary Anthropology, Duke University, Durham, NC
- Department of Biology, Duke University, Durham, NC
- Duke University Population Research Institute, Duke University, Durham, NC
- Institute of Primate Research, National Museums of Kenya, Karen, Nairobi, Kenya
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Whittle CA, Extavour CG. Selection shapes turnover and magnitude of sex-biased expression in Drosophila gonads. BMC Evol Biol 2019; 19:60. [PMID: 30786879 PMCID: PMC6383255 DOI: 10.1186/s12862-019-1377-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 01/23/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Sex-biased gene expression is thought to drive the phenotypic differences in males and females in metazoans. Drosophila has served as a primary model for studying male-female differences in gene expression, and its effects on protein sequence divergence. However, the forces shaping evolution of sex-biased expression remain largely unresolved, including the roles of selection and pleiotropy. Research on sex organs in Drosophila, employing original approaches and multiple-species contrasts, provides a means to gain insights into factors shaping the turnover and magnitude (fold-bias) of sex-biased expression. RESULTS Here, using recent RNA-seq data, we studied sex-biased gonadal expression in 10,740 protein coding sequences in four species of Drosophila, D. melanogaster, D. simulans, D. yakuba and D. ananassae (5 to 44 My divergence). Using an approach wherein we identified genes with lineage-specific transitions (LSTs) in sex-biased status (amongst testis-biased, ovary-biased and unbiased; thus, six transition types) standardized to the number of genes with the ancestral state (S-LSTs), and those with clade-wide expression bias status, we reveal several key findings. First, the six categorical types of S-LSTs in sex-bias showed disparate rates of turnover, consistent with differential selection pressures. Second, the turnover in sex-biased status was largely unrelated to cross-tissue expression breadth, suggesting pleiotropy does not restrict evolution of sex-biased expression. Third, the fold-sex-biased expression, for both testis-biased and ovary-biased genes, evolved directionally over time toward higher values, a crucial finding that could be interpreted as a selective advantage of greater sex-bias, and sexual antagonism. Fourth, in terms of protein divergence, genes with LSTs to testis-biased expression exhibited weak signals of elevated rates of evolution (than ovary-biased) in as little as 5 My, which strengthened over time. Moreover, genes with clade-wide testis-specific expression (44 My), a status not observed for any ovary-biased genes, exhibited striking acceleration of protein divergence, which was linked to low pleiotropy. CONCLUSIONS By studying LSTs and clade-wide sex-biased gonadal expression in a multi-species clade of Drosophila, we describe evidence that interspecies turnover and magnitude of sex-biased expression have been influenced by selection. Further, whilst pleiotropy was not connected to turnover in sex-biased gonadal expression, it likely explains protein sequence divergence.
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Affiliation(s)
- Carrie A Whittle
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA, 02138, USA
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA, 02138, USA.
- Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA, 02138, USA.
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Lipinska AP, Serrano-Serrano ML, Cormier A, Peters AF, Kogame K, Cock JM, Coelho SM. Rapid turnover of life-cycle-related genes in the brown algae. Genome Biol 2019; 20:35. [PMID: 30764885 PMCID: PMC6374913 DOI: 10.1186/s13059-019-1630-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 01/16/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sexual life cycles in eukaryotes involve a cyclic alternation between haploid and diploid phases. While most animals possess a diploid life cycle, many plants and algae alternate between multicellular haploid (gametophyte) and diploid (sporophyte) generations. In many algae, gametophytes and sporophytes are independent and free-living and may present dramatic phenotypic differences. The same shared genome can therefore be subject to different, even conflicting, selection pressures during each of the life cycle generations. Here, we analyze the nature and extent of genome-wide, generation-biased gene expression in four species of brown algae with contrasting levels of dimorphism between life cycle generations. RESULTS We show that the proportion of the transcriptome that is generation-specific is broadly associated with the level of phenotypic dimorphism between the life cycle stages. Importantly, our data reveals a remarkably high turnover rate for life-cycle-related gene sets across the brown algae and highlights the importance not only of co-option of regulatory programs from one generation to the other but also of a role for newly emerged, lineage-specific gene expression patterns in the evolution of the gametophyte and sporophyte developmental programs in this major eukaryotic group. Moreover, we show that generation-biased genes display distinct evolutionary modes, with gametophyte-biased genes evolving rapidly at the coding sequence level whereas sporophyte-biased genes tend to exhibit changes in their patterns of expression. CONCLUSION Our analysis uncovers the characteristics, expression patterns, and evolution of generation-biased genes and underlines the selective forces that shape this previously underappreciated source of phenotypic diversity.
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Affiliation(s)
- Agnieszka P Lipinska
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | | | - Alexandre Cormier
- Laboratoire Ecologie et Biologie des Interactions, Equipe Ecologie Evolution Symbiose, Université de Poitiers, UMR CNRS 7267, Poitiers, France
| | | | - Kazuhiro Kogame
- Department of Biological Sciences, Faculty of Sciences, Hokkaido University, Sapporo, 060-0810, Japan
| | - J Mark Cock
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France
| | - Susana M Coelho
- Sorbonne Université, UPMC Univ Paris 06, CNRS, Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, F-29688, Roscoff, France.
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Osman NM, Kitapci TH, Vlaho S, Wunderlich Z, Nuzhdin SV. Inference of Transcription Factor Regulation Patterns Using Gene Expression Covariation in Natural Populations of Drosophila melanogaster. Biophysics (Nagoya-shi) 2019; 63:43-51. [PMID: 30739944 DOI: 10.1134/s0006350918010128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Gene regulatory networks control the complex programs that drive development. Deciphering the connections between transcription factors (TFs) and target genes is challenging, in part because TFs bind to thousands of places in the genome but control expression through a subset of these binding events. We hypothesize that we can combine natural variation of expression levels and predictions of TF binding sites to identify TF targets. We gather RNA-seq data from 71 genetically distinct F1 Drosophila melanogaster embryos and calculate the correlations between TF and potential target genes' expression levels, which we call "regulatory strength." To separate direct and indirect TF targets, we hypothesize that direct TF targets will have a preponderance of binding sites in their upstream regions. Using 14 TFs active during embryogenesis, we find that 12 TFs showed a significant correlation between their binding strength and regulatory strength on downstream targets, and 10 TFs showed a significant correlation between the number of binding sites and the regulatory effect on target genes. The general roles, e.g. bicoid's role as an activator, and the particular interactions we observed between our TFs, e.g. twist's role as a repressor of sloppy paired and odd paired, generally coincide with the literature.
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Affiliation(s)
- Noha M Osman
- University of Southern California, Los Angeles, CA.,National Research Centre, Dokki, Giza, Egypt
| | | | - Srna Vlaho
- University of Southern California, Los Angeles, CA
| | | | - Sergey V Nuzhdin
- University of Southern California, Los Angeles, CA.,Saint Petersburg Polytechnical University, St Petersburg, Russia
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Assis R. Lineage-Specific Expression Divergence in Grasses Is Associated with Male Reproduction, Host-Pathogen Defense, and Domestication. Genome Biol Evol 2019; 11:207-219. [PMID: 30398650 PMCID: PMC6331041 DOI: 10.1093/gbe/evy245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2018] [Indexed: 02/02/2023] Open
Abstract
Poaceae (grasses) is an agriculturally important and widely distributed family of plants with extraordinary phenotypic diversity, much of which was generated under recent lineage-specific evolution. Yet, little is known about the genes and functional modules involved in the lineage-specific divergence of grasses. Here, I address this question on a genome-wide scale by applying a novel branch-based statistic of lineage-specific expression divergence, LED, to RNA-seq data from nine tissues of the wild grass Brachypodium distachyon and its domesticated relatives Oryza sativa japonica (rice) and Sorghum bicolor (sorghum). I find that LED is generally smallest in B. distachyon and largest in O. sativa japonica, which underwent domestication earlier than S. bicolor, supporting the hypothesis that domestication may increase the rate of lineage-specific expression divergence in grasses. Moreover, in all three species, LED is positively correlated with protein-coding sequence divergence and tissue specificity, and negatively correlated with network connectivity. Further analysis reveals that genes with large LED are often primarily expressed in anther, implicating lineage-specific expression divergence in the evolution of male reproductive phenotypes. Gene ontology enrichment analysis also identifies an overrepresentation of terms related to male reproduction in the two domesticated grasses, as well as to those involved in host-pathogen defense in all three species. Last, examinations of genes with the largest LED reveal that their lineage-specific expression divergence may have contributed to antimicrobial functions in B. distachyon, to enhanced adaptation and yield during domestication in O. sativa japonica, and to defense against a widespread and devastating fungal pathogen in S. bicolor. Together, these findings suggest that lineage-specific expression divergence in grasses may increase under domestication and preferentially target rapidly evolving genes involved in male reproduction, host-pathogen defense, and the origin of domesticated phenotypes.
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Affiliation(s)
- Raquel Assis
- Department of Biology, Pennsylvania State University, University Park
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36
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Rivas MJ, Saura M, Pérez-Figueroa A, Panova M, Johansson T, André C, Caballero A, Rolán-Alvarez E, Johannesson K, Quesada H. Population genomics of parallel evolution in gene expression and gene sequence during ecological adaptation. Sci Rep 2018; 8:16147. [PMID: 30385764 PMCID: PMC6212547 DOI: 10.1038/s41598-018-33897-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 10/08/2018] [Indexed: 11/17/2022] Open
Abstract
Natural selection often produces parallel phenotypic changes in response to a similar adaptive challenge. However, the extent to which parallel gene expression differences and genomic divergence underlie parallel phenotypic traits and whether they are decoupled or not remains largely unexplored. We performed a population genomic study of parallel ecological adaptation among replicate ecotype pairs of the rough periwinkle (Littorina saxatilis) at a regional geographical scale (NW Spain). We show that genomic changes underlying parallel phenotypic divergence followed a complex pattern of both repeatable differences and of differences unique to specific ecotype pairs, in which parallel changes in expression or sequence are restricted to a limited set of genes. Yet, the majority of divergent genes were divergent either for gene expression or coding sequence, but not for both simultaneously. Overall, our findings suggest that divergent selection significantly contributed to the process of parallel molecular differentiation among ecotype pairs, and that changes in expression and gene sequence underlying phenotypic divergence could, at least to a certain extent, be considered decoupled processes.
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Affiliation(s)
- María José Rivas
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain
| | - María Saura
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain
| | - Andrés Pérez-Figueroa
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain
| | - Marina Panova
- Department of Marine Sciences, Tjärnö, University of Gothenburg, SE-452 96, Strömstad, Sweden
| | - Tomas Johansson
- Department of Biology, University of Lund, SE-223 62, Lund, Sweden
| | - Carl André
- Department of Marine Sciences, Tjärnö, University of Gothenburg, SE-452 96, Strömstad, Sweden
| | - Armando Caballero
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain
| | - Emilio Rolán-Alvarez
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain
| | - Kerstin Johannesson
- Department of Marine Sciences, Tjärnö, University of Gothenburg, SE-452 96, Strömstad, Sweden
| | - Humberto Quesada
- Departamento de Bioquímica, Genética e Inmunología, Universidad de Vigo, 36310, Vigo, Spain.
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Ghiselli F, Iannello M, Puccio G, Chang PL, Plazzi F, Nuzhdin SV, Passamonti M. Comparative Transcriptomics in Two Bivalve Species Offers Different Perspectives on the Evolution of Sex-Biased Genes. Genome Biol Evol 2018; 10:1389-1402. [PMID: 29897459 PMCID: PMC6007409 DOI: 10.1093/gbe/evy082] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2018] [Indexed: 12/13/2022] Open
Abstract
Comparative genomics has become a central tool for evolutionary biology, and a better knowledge of understudied taxa represents the foundation for future work. In this study, we characterized the transcriptome of male and female mature gonads in the European clam Ruditapes decussatus, compared with that in the Manila clam Ruditapes philippinarum providing, for the first time in bivalves, information about transcription dynamics and sequence evolution of sex-biased genes. In both the species, we found a relatively low number of sex-biased genes (1,284, corresponding to 41.3% of the orthologous genes between the two species), probably due to the absence of sexual dimorphism, and the transcriptional bias is maintained in only 33% of the orthologs. The dN/dS is generally low, indicating purifying selection, with genes where the female-biased transcription is maintained between the two species showing a significantly higher dN/dS. Genes involved in embryo development, cell proliferation, and maintenance of genome stability show a faster sequence evolution. Finally, we report a lack of clear correlation between transcription level and evolutionary rate in these species, in contrast with studies that reported a negative correlation. We discuss such discrepancy and call into question some methodological approaches and rationales generally used in this type of comparative studies.
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Affiliation(s)
- Fabrizio Ghiselli
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
| | - Mariangela Iannello
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
| | - Guglielmo Puccio
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
| | - Peter L Chang
- Program in Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, USA
| | - Federico Plazzi
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
| | - Sergey V Nuzhdin
- Program in Molecular and Computational Biology, Department of Biological Sciences, University of Southern California, Los Angeles, USA
| | - Marco Passamonti
- Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy
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Genes Integral to the Reproductive Function of Male Reproductive Tissues Drive Heterogeneity in Evolutionary Rates in Japanese Quail. G3-GENES GENOMES GENETICS 2018; 8:39-51. [PMID: 29158338 PMCID: PMC5765365 DOI: 10.1534/g3.117.300095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Early comparative genomics studies originally uncovered a nonintuitive pattern; genes involved in reproduction appeared to evolve more rapidly than other classes of genes. Currently, the emerging consensus is that genes encoding reproductive proteins evolve under variable selective pressures, producing more heterogeneous divergence patterns than previously appreciated. Here, we investigate a facet of that heterogeneity and explore the factors that drive male reproductive tissue-based heterogeneity in evolutionary rates. In Japanese quail (Coturnix japonica), genes with enriched expression in the testes evolve much more rapidly than those enriched in the foam gland (FG), a novel gland that secretes an airy foam that males transfer to females during mating. We compared molecular evolutionary patterns among (1) genes with induced expression in breeding vs. wintering conditions for both tissues and (2) genes that encode foam proteins (FPs) vs. those with varying degrees of expression specificity in the FG. We report two major findings. First, genes upregulated in breeding condition testes evolve exceptionally rapidly, while those induced in breeding condition FGs evolve slowly. These differences hold even after correcting for hormonally-dependent gene expression and chromosomal location. Second, genes encoding FPs are extremely conserved in terms of gene identity and sequence. Together, these finding suggest that genes involved in the reproductive function of each tissue drive the marked rate of heterogeneity.
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39
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Manenti T, Loeschcke V, Sørensen JG. Constitutive up-regulation of Turandot genes rather than changes in acclimation ability is associated with the evolutionary adaptation to temperature fluctuations in Drosophila simulans. JOURNAL OF INSECT PHYSIOLOGY 2018; 104:40-47. [PMID: 29175088 DOI: 10.1016/j.jinsphys.2017.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 06/07/2023]
Abstract
Most research on thermal adaptation of ectotherms is based on experiments performed at constant temperatures. However, for short-lived insects daily fluctuations of temperature could be an important environmental parameter involved in evolutionary adaptation to thermal heterogeneity. In this study we investigated the mechanisms underlying evolutionary adaptation to daily fluctuating temperatures. We studied replicated selection lines of Drosophila simulans evolved in a constant or a daily fluctuating thermal regime. Previous studies of these lines have shown clear acclimation benefits to heat tolerance induced by the fluctuating regime. First, we tested the existence of an evolved circadian controlled adjustment of heat resistance in selected flies. This was done by investigating the daily variation in time to heat knockdown in flies from both selection regimes when exposed to either a constant or a daily fluctuating thermal regime for a single generation. While daily variation in heat resistance was found, the results suggest that there was neither an evolved adaptive circadian controlled adjustment of heat resistance nor a continuous acclimation response induced by fluctuating temperatures in these lines. Second, in order to reveal functional candidates for adaptation to the fluctuating thermal regime, we investigated the global transcriptomic response to a high temperature exposure in flies from both regimes. We found that flies selected both in constant and fluctuating thermal regimes responded similarly to increasing temperature. However, we found that evolutionary adaptation to the fluctuating thermal regime led to transcriptional enrichment of the GO terms eggshell chorion assembly and cellular response to heat. The latter category was constituted by a constitutive up-regulation of four Turandot genes and not heat shock protein genes, suggesting that Turandot genes could play a prominent role for adaptation to daily fluctuating thermal conditions.
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Affiliation(s)
- Tommaso Manenti
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114-116, Buildg. 1540, DK-8000 Aarhus C, Denmark
| | - Volker Loeschcke
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114-116, Buildg. 1540, DK-8000 Aarhus C, Denmark
| | - Jesper Givskov Sørensen
- Department of Bioscience, Section for Genetics, Ecology and Evolution, Aarhus University, Ny Munkegade 114-116, Buildg. 1540, DK-8000 Aarhus C, Denmark.
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40
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Schrader L, Helanterä H, Oettler J. Accelerated Evolution of Developmentally Biased Genes in the Tetraphenic Ant Cardiocondyla obscurior. Mol Biol Evol 2017; 34:535-544. [PMID: 27999112 PMCID: PMC5400372 DOI: 10.1093/molbev/msw240] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Plastic gene expression underlies phenotypic plasticity and plastically expressed genes evolve under different selection regimes compared with ubiquitously expressed genes. Social insects are well-suited models to elucidate the evolutionary dynamics of plastic genes for their genetically and environmentally induced discrete polymorphisms. Here, we study the evolution of plastically expressed genes in the ant Cardiocondyla obscurior—a species that produces two discrete male morphs in addition to the typical female polymorphism of workers and queens. Based on individual-level gene expression data from 28 early third instar larvae, we test whether the same evolutionary dynamics that pertain to plastically expressed genes in adults also pertain to genes with plastic expression during development. In order to quantify plasticity of gene expression over multiple contrasts, we develop a novel geometric measure. For genes expressed during development, we show that plasticity of expression is positively correlated with evolutionary rates. We furthermore find a strong correlation between expression plasticity and expression variation within morphs, suggesting a close link between active and passive plasticity of gene expression. Our results support the notion of relaxed selection and neutral processes as important drivers in the evolution of adaptive plasticity.
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Affiliation(s)
- Lukas Schrader
- Institut für Zoologie, Universität Regensburg, Regensburg, Germany.,Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Heikki Helanterä
- Centre of Excellence in Biological Interactions, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Jan Oettler
- Institut für Zoologie, Universität Regensburg, Regensburg, Germany
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41
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Cis- and Trans-regulatory Effects on Gene Expression in a Natural Population of Drosophila melanogaster. Genetics 2017; 206:2139-2148. [PMID: 28615283 DOI: 10.1534/genetics.117.201459] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/06/2017] [Indexed: 12/30/2022] Open
Abstract
Cis- and trans-regulatory mutations are important contributors to transcriptome evolution. Quantifying their relative contributions to intraspecific variation in gene expression is essential for understanding the population genetic processes that underlie evolutionary changes in gene expression. Here, we have examined this issue by quantifying genome-wide, allele-specific expression (ASE) variation using a crossing scheme that produces F1 hybrids between 18 different Drosophila melanogaster strains sampled from the Drosophila Genetic Reference Panel and a reference strain from another population. Head and body samples from F1 adult females were subjected to RNA sequencing and the subsequent ASE quantification. Cis- and trans-regulatory effects on expression variation were estimated from these data. A higher proportion of genes showed significant cis-regulatory variation (∼28%) than those that showed significant trans-regulatory variation (∼9%). The sizes of cis-regulatory effects on expression variation were 1.98 and 1.88 times larger than trans-regulatory effects in heads and bodies, respectively. A generalized linear model analysis revealed that both cis- and trans-regulated expression variation was strongly associated with nonsynonymous nucleotide diversity and tissue specificity. Interestingly, trans-regulated variation showed a negative correlation with local recombination rate. Also, our analysis on proximal transposable element (TE) insertions suggested that they affect transcription levels of ovary-expressed genes more pronouncedly than genes not expressed in the ovary, possibly due to defense mechanisms against TE mobility in the germline. Collectively, our detailed quantification of ASE variations from a natural population has revealed a number of new relationships between genomic factors and the effects of cis- and trans-regulatory factors on expression variation.
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42
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Pespeni MH, Ladner JT, Moczek AP. Signals of selection in conditionally expressed genes in the diversification of three horned beetle species. J Evol Biol 2017; 30:1644-1657. [PMID: 28379613 DOI: 10.1111/jeb.13079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 03/05/2017] [Indexed: 01/20/2023]
Abstract
Species radiations may be facilitated by phenotypic differences already present within populations, such as those arising through sex-specific development or developmental processes biased towards particular reproductive or trophic morphs. We sought to test this hypothesis by utilizing a comparative transcriptomic approach to contrast among- and within-species differentiation using three horned beetle species in the genus Onthophagus. These three species exhibit differences along three phenotypic axes reflective of much of the interspecific diversity present within the genus: horn location, polarity of sexual dimorphism and degree of nutritional sensitivity. Our approach combined de novo transcript assembly, assessment of amino acid substitutions (dN/dS) across orthologous gene pairs and integration of gene function and conditional gene expression data. We identified 17 genes across the three species pairs related to axis patterning, development and metabolism with dN/dS > 1 and detected elevated dN/dS in genes related to metabolism and biosynthesis in the most closely related species pair, which is characterized by a loss of nutritional polyphenism and a reversal of sexual dimorphism. Further, we found that genes that are conditionally expressed (i.e. as a function of sex, nutrition or body region) within one of our focal species also showed significantly stronger signals of positive or relaxed purifying selection between species divergent along the same morphological axis (i.e. polarity of sexual dimorphism, degree of nutritional sensitivity or location of horns). Our findings thus reveal a positive relationship between intraspecific differentiation due to condition-specific development and genetic divergences among species.
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Affiliation(s)
- M H Pespeni
- Department of Biology, Indiana University, Bloomington, IN, USA.,Department of Biology, University of Vermont, Burlington, VT, USA
| | - J T Ladner
- Center for Genome Sciences, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA
| | - A P Moczek
- Department of Biology, Indiana University, Bloomington, IN, USA
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43
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Semlali A, Parine NR, Al Amri A, Azzi A, Arafah M, Kohailan M, Shaik JP, Almadi MA, Aljebreen AM, Alharbi O, Ali Azzam N, Rouabhia M, Alanazi MS. Association between TLR-9 polymorphisms and colon cancer susceptibility in Saudi Arabian female patients. Onco Targets Ther 2016; 10:1-11. [PMID: 28031717 PMCID: PMC5179201 DOI: 10.2147/ott.s106024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Objective The authors aimed to explore the relationship between the expression/polymorphisms of TLR-9 and susceptibility to colon cancer development in the Saudi Arabian population. Methods In total, blood samples from 115 patients with colon cancer and 102 participants without colon cancer were analyzed in this study. Three single-nucleotide polymorphisms (SNPs) were selected from the TLR-9 gene, including two sites within the TLR-9 gene’s promoter region (rs352144 and rs187084) and one site in a TLR-9 intron region (rs5743839). Odds ratios (ORs) and 95% confidence intervals (CIs) were computed from logistic regression models after adjusting for age, gender, and tumor localization. To investigate the differential expression of TLR-9 in colon cancer, TLR-9 expression was evaluated using quantitative real-time reverse transcription polymerase chain reaction on 40 matched normal and colon tissues. Results The authors found that TLR-9 expression was decreased in colon cancer tissues as compared with that in normal tissues. Moreover, significant associations between the TLR-9 rs187084 SNP and colon cancer risk were observed in female patients only. In rs187084, the T allele had a significantly lower frequency (2.8 times) in female cancer patients than in controls (0.27 vs 0.41). The TLR-9 rs352139 and rs352144 SNPs were significantly associated with colon cancer development when the tumor was located in the rectal area. Conclusion The findings support the hypothesis that TLR-9 has an anticancer role in colon cancer development. Furthermore, genetic variation may influence colon cancer development, and SNPs in TLR-9 could serve as biomarkers for decision making in the treatment of females with rectal cancer.
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Affiliation(s)
- Abdelhabib Semlali
- Genome Research, Department of Biochemistry, College of Sciences, King Saud University
| | | | - Abdullah Al Amri
- Genome Research, Department of Biochemistry, College of Sciences, King Saud University
| | - Arezki Azzi
- College of Medicine, Al Imam Muhammad Ibn Saud Islamic University
| | | | - Muhammad Kohailan
- Genome Research, Department of Biochemistry, College of Sciences, King Saud University
| | - Jilani P Shaik
- Genome Research, Department of Biochemistry, College of Sciences, King Saud University
| | - Majid Abdulrahman Almadi
- Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia; Division of Gastroenterology, McGill University Health Center, Montreal General Hospital, Montreal
| | - Abdulrahman M Aljebreen
- College of Medicine, King Saud University; Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Othman Alharbi
- College of Medicine, King Saud University; Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Nahla Ali Azzam
- College of Medicine, King Saud University; Division of Gastroenterology, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Mahmoud Rouabhia
- Groupe de Recherche en Écologie Buccale, Département de Stomatologie, Faculté de Médecine Dentaire, Université Laval, Québec City, QC, Canada
| | - Mohammad Saud Alanazi
- Genome Research, Department of Biochemistry, College of Sciences, King Saud University
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44
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Xiao MS, Zhang B, Li YS, Gao Q, Sun W, Chen W. Global analysis of regulatory divergence in the evolution of mouse alternative polyadenylation. Mol Syst Biol 2016; 12:890. [PMID: 27932516 PMCID: PMC5199128 DOI: 10.15252/msb.20167375] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Alternative polyadenylation (APA), which is regulated by both cis‐elements and trans‐factors, plays an important role in post‐transcriptional regulation of eukaryotic gene expression. However, comparing to the extensively studied transcription and alternative splicing, the extent of APA divergence during evolution and the relative cis‐ and trans‐contribution remain largely unexplored. To directly address these questions for the first time in mammals, by using deep sequencing‐based methods, we measured APA divergence between C57BL/6J and SPRET/EiJ mouse strains as well as allele‐specific APA pattern in their F1 hybrids. Among the 24,721 polyadenylation sites (pAs) from 7,271 genes expressing multiple pAs, we identified 3,747 pAs showing significant divergence between the two strains. After integrating the allele‐specific data from F1 hybrids, we demonstrated that these events could be predominately attributed to cis‐regulatory effects. Further systematic sequence analysis of the regions in proximity to cis‐divergent pAs revealed that the local RNA secondary structure and a poly(U) tract in the upstream region could negatively modulate the pAs usage.
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Affiliation(s)
- Mei-Sheng Xiao
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Berlin, Germany
| | - Bin Zhang
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Berlin, Germany.,Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yi-Sheng Li
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Berlin, Germany
| | - Qingsong Gao
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Berlin, Germany
| | - Wei Sun
- Laboratory for Functional Genomics and Systems Biology, Berlin Institute for Medical Systems Biology, Berlin, Germany.,Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Wei Chen
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China .,Medi-X Institute, SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
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45
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Dean R, Wright AE, Marsh‐Rollo SE, Nugent BM, Alonzo SH, Mank JE. Sperm competition shapes gene expression and sequence evolution in the ocellated wrasse. Mol Ecol 2016; 26:505-518. [DOI: 10.1111/mec.13919] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 10/31/2016] [Accepted: 11/03/2016] [Indexed: 01/19/2023]
Affiliation(s)
- Rebecca Dean
- Department of Genetics, Evolution and Environment University College London London UK
- School of Biological Sciences Monash University Clayton VIC Australia
| | - Alison E. Wright
- Department of Genetics, Evolution and Environment University College London London UK
| | - Susan E. Marsh‐Rollo
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Santa Cruz CA USA
- Department of Psychology Neuroscience & Behaviour McMaster University Hamilton Ontario Canada
| | - Bridget M. Nugent
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
- Department of Biomedical Sciences University of Pennsylvania Philadelphia PA USA
| | - Suzanne H. Alonzo
- Department of Ecology and Evolutionary Biology University of California Santa Cruz Santa Cruz CA USA
- Department of Ecology and Evolutionary Biology Yale University New Haven CT USA
| | - Judith E. Mank
- Department of Genetics, Evolution and Environment University College London London UK
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46
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Turner KG, Nurkowski KA, Rieseberg LH. Gene expression and drought response in an invasive thistle. Biol Invasions 2016. [DOI: 10.1007/s10530-016-1308-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Cardoso GA, Marinho MAT, Monfardini RD, Espin AMLDA, Torres TT. Evolution of genes involved in feeding preference and metabolic processes in Calliphoridae (Diptera: Calyptratae). PeerJ 2016; 4:e2598. [PMID: 27812410 PMCID: PMC5088637 DOI: 10.7717/peerj.2598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 09/23/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND The genotype-phenotype interactions among traits governing feeding preference are of fundamental importance to behavioral genetics and evolutionary biology. The genetic basis of behavioral traits has been explored in different taxa using different approaches. However, the complex nature of the genetic mechanisms undergirding behavior is poorly understood. Here, we present an evolutionary study of candidate genes related to parasitism in Calliphoridae (Diptera: Calyptratae). Closely related species in this family exhibit distinct larval feeding habits, most notably necro-saprophagy and obligate parasitism. METHODS To understand the genetic and molecular bases underlying these habits, expression levels of eight candidate genes for feeding behavior-Cyp6g2, foraging, glutamate dehydrogenase, Jonah65aiv, Malvolio, PGRP-SC2, RPS6-p70-protein kinase, and smooth-were measured in four species using qPCR. Moreover we used expression values and sequence information to reconstruct the relationship among species and the dN/dS rate to infer possible sites under selection. RESULTS For most candidate genes, no statistically significant differences were observed, indicating a high degree of conservation in expression. However, Malvolio was differentially expressed between habits. Evolutionary analyses based on transcript levels and nucleotide sequences of Malvolio coding region suggest that transcript levels were correlated to feeding habit preferences among species, although deviations under a strictly neutral model were also observed in statistical tests. DISCUSSION Malvolio was the only gene demonstrating a possible connection to feeding habit. Differences in gene expression may be involved in (or be a result of) the genetic regulation of Calliphoridae feeding habit. Our results are the first steps towards understanding the genetic basis and evolution of feeding behavior in Calliphoridae using a functional approach.
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Affiliation(s)
| | - Marco Antonio Tonus Marinho
- Department of Biology, Faculty of Philosophy, Science, and Letters, University of Sao Paulo , Ribeirao Preto , Sao Paulo , Brazil
| | | | | | - Tatiana Teixeira Torres
- Department of Genetics and Evolutionary Biology, University of Sao Paulo , Sao Paulo , Brazil
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48
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Buffering of Genetic Regulatory Networks in Drosophila melanogaster. Genetics 2016; 203:1177-90. [PMID: 27194752 DOI: 10.1534/genetics.116.188797] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/17/2016] [Indexed: 01/01/2023] Open
Abstract
Regulatory variation in gene expression can be described by cis- and trans-genetic components. Here we used RNA-seq data from a population panel of Drosophila melanogaster test crosses to compare allelic imbalance (AI) in female head tissue between mated and virgin flies, an environmental change known to affect transcription. Indeed, 3048 exons (1610 genes) are differentially expressed in this study. A Bayesian model for AI, with an intersection test, controls type I error. There are ∼200 genes with AI exclusively in mated or virgin flies, indicating an environmental component of expression regulation. On average 34% of genes within a cross and 54% of all genes show evidence for genetic regulation of transcription. Nearly all differentially regulated genes are affected in cis, with an average of 63% of expression variation explained by the cis-effects. Trans-effects explain 8% of the variance in AI on average and the interaction between cis and trans explains an average of 11% of the total variance in AI. In both environments cis- and trans-effects are compensatory in their overall effect, with a negative association between cis- and trans-effects in 85% of the exons examined. We hypothesize that the gene expression level perturbed by cis-regulatory mutations is compensated through trans-regulatory mechanisms, e.g., trans and cis by trans-factors buffering cis-mutations. In addition, when AI is detected in both environments, cis-mated, cis-virgin, and trans-mated-trans-virgin estimates are highly concordant with 99% of all exons positively correlated with a median correlation of 0.83 for cis and 0.95 for trans We conclude that the gene regulatory networks (GRNs) are robust and that trans-buffering explains robustness.
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49
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Milan M, Matozzo V, Pauletto M, Di Camillo B, Giacomazzo M, Boffo L, Binato G, Marin MG, Patarnello T, Bargelloni L. Can ecological history influence response to pollutants? Transcriptomic analysis of Manila clam collected in different Venice lagoon areas and exposed to heavy metal. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 174:123-133. [PMID: 26945539 DOI: 10.1016/j.aquatox.2016.02.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 02/26/2016] [Accepted: 02/27/2016] [Indexed: 06/05/2023]
Abstract
Chronic exposure to environmental pollutants can exert strong selective pressures on natural populations, favoring the transmission over generations of traits that enable individuals to survive and thrive in highly impacted environments. The lagoon of Venice is an ecosystem subject to heavy anthropogenic impact, mainly due to the industrial activities of Porto Marghera (PM), which led to a severe chemical contamination of soil, groundwater, and sediments. Gene expression analysis on wild Manila clams collected in different Venice lagoon areas enabled to identify differences in gene expression profiles between clams collected in PM and those sampled in clean areas, and the definition of molecular signatures of chemical stress. However, it remains largely unexplored to which extent modifications of gene expression patterns persists after removing the source of contamination. It is also relatively unknown whether chronic exposure to xenobiotics affects the response to other chemical pollutants. To start exploring such issues, in the present study a common-garden experiment was coupled with transcriptomic analysis, to compare gene expression profiles of PM clams with those of clams collected in the less impacted area of Chioggia (CH) during a period under the same control conditions. Part of the two experimental groups were also exposed to copper for seven days to assess whether different "ecological history" does influence response to such pollutant. The results obtained suggest that the chronic exposure to chemical pollution generated a response at the transcriptional level that persists after removal for the contaminated site. These transcriptional changes are centered on key biological processes, such as defense against either oxidative stress or tissue/protein damage, and detoxification, suggesting an adaptive strategy for surviving in the deeply impacted environment of Porto Marghera. On the other hand, CH clams appeared to respond more effectively to copper exposure than PM animals, proposing that chronic exposure to chemical toxicants either lowers the sensitivity to additional toxicants or blunts the capacity to respond to novel chemical challenges in PM clams.
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Affiliation(s)
- Massimo Milan
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy.
| | - Valerio Matozzo
- Department of Biology, University of Padova, via G. Colombo 3, 35131 Padova, Italy
| | - Marianna Pauletto
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy
| | | | - Matteo Giacomazzo
- Department of Biology, University of Padova, via G. Colombo 3, 35131 Padova, Italy; Department of Environmental Sciences University of Quèbec at Trois-Rivières, Canada
| | | | - Giovanni Binato
- Laboratory of Chemistry, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy
| | | | - Tomaso Patarnello
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy
| | - Luca Bargelloni
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy
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50
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Uebbing S, Künstner A, Mäkinen H, Backström N, Bolivar P, Burri R, Dutoit L, Mugal CF, Nater A, Aken B, Flicek P, Martin FJ, Searle SMJ, Ellegren H. Divergence in gene expression within and between two closely related flycatcher species. Mol Ecol 2016; 25:2015-28. [PMID: 26928872 PMCID: PMC4879514 DOI: 10.1111/mec.13596] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/15/2016] [Accepted: 02/17/2016] [Indexed: 12/12/2022]
Abstract
Relatively little is known about the character of gene expression evolution as species diverge. It is for instance unclear if gene expression generally evolves in a clock‐like manner (by stabilizing selection or neutral evolution) or if there are frequent episodes of directional selection. To gain insights into the evolutionary divergence of gene expression, we sequenced and compared the transcriptomes of multiple organs from population samples of collared (Ficedula albicollis) and pied flycatchers (F. hypoleuca), two species which diverged less than one million years ago. Ordination analysis separated samples by organ rather than by species. Organs differed in their degrees of expression variance within species and expression divergence between species. Variance was negatively correlated with expression breadth and protein interactivity, suggesting that pleiotropic constraints reduce gene expression variance within species. Variance was correlated with between‐species divergence, consistent with a pattern expected from stabilizing selection and neutral evolution. Using an expression PST approach, we identified genes differentially expressed between species and found 16 genes uniquely expressed in one of the species. For one of these, DPP7, uniquely expressed in collared flycatcher, the absence of expression in pied flycatcher could be associated with a ≈20‐kb deletion including 11 of 13 exons. This study of a young vertebrate speciation model system expands our knowledge of how gene expression evolves as natural populations become reproductively isolated.
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Affiliation(s)
- Severin Uebbing
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Axel Künstner
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Hannu Mäkinen
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Niclas Backström
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Paulina Bolivar
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Reto Burri
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Ludovic Dutoit
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Carina F Mugal
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Alexander Nater
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
| | - Bronwen Aken
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Paul Flicek
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Fergal J Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.,Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Stephen M J Searle
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Hans Ellegren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36 Uppsala, Sweden
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