1
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Wang Y, Duchen P, Chávez A, Sree KS, Appenroth KJ, Zhao H, Höfer M, Huber M, Xu S. Population genomics and epigenomics of Spirodela polyrhiza provide insights into the evolution of facultative asexuality. Commun Biol 2024; 7:581. [PMID: 38755313 PMCID: PMC11099151 DOI: 10.1038/s42003-024-06266-7] [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: 08/01/2023] [Accepted: 04/30/2024] [Indexed: 05/18/2024] Open
Abstract
Many plants are facultatively asexual, balancing short-term benefits with long-term costs of asexuality. During range expansion, natural selection likely influences the genetic controls of asexuality in these organisms. However, evidence of natural selection driving asexuality is limited, and the evolutionary consequences of asexuality on the genomic and epigenomic diversity remain controversial. We analyzed population genomes and epigenomes of Spirodela polyrhiza, (L.) Schleid., a facultatively asexual plant that flowers rarely, revealing remarkably low genomic diversity and DNA methylation levels. Within species, demographic history and the frequency of asexual reproduction jointly determined intra-specific variations of genomic diversity and DNA methylation levels. Genome-wide scans revealed that genes associated with stress adaptations, flowering and embryogenesis were under positive selection. These data are consistent with the hypothesize that natural selection can shape the evolution of asexuality during habitat expansions, which alters genomic and epigenomic diversity levels.
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Affiliation(s)
- Yangzi Wang
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany
- Institute for Evolution and Biodiversity, University of Münster, 48161, Münster, Germany
| | - Pablo Duchen
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany
- Institute for Evolution and Biodiversity, University of Münster, 48161, Münster, Germany
| | - Alexandra Chávez
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany
- Institute for Evolution and Biodiversity, University of Münster, 48161, Münster, Germany
- Institute of Plant Biology and Biotechnology, University of Münster, 48161, Münster, Germany
| | - K Sowjanya Sree
- Department of Environmental Science, Central University of Kerala, Periya, 671320, India
| | - Klaus J Appenroth
- Matthias Schleiden Institute - Plant Physiology, Friedrich Schiller University of Jena, 07743, Jena, Germany
| | - Hai Zhao
- Chengdu Institute of Biology, Chinese Academy of Sciences, 6100641, Chengdu, China
| | - Martin Höfer
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany
- Institute for Evolution and Biodiversity, University of Münster, 48161, Münster, Germany
| | - Meret Huber
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany
- Institute of Plant Biology and Biotechnology, University of Münster, 48161, Münster, Germany
| | - Shuqing Xu
- Institute of Organismic and Molecular Evolution, University of Mainz, 55128, Mainz, Germany.
- Institute for Evolution and Biodiversity, University of Münster, 48161, Münster, Germany.
- Institute for Quantitative and Computational Biosciences, University of Mainz, 55218, Mainz, Germany.
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2
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Hogg CJ. Translating genomic advances into biodiversity conservation. Nat Rev Genet 2024; 25:362-373. [PMID: 38012268 DOI: 10.1038/s41576-023-00671-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2023] [Indexed: 11/29/2023]
Abstract
A key action of the new Global Biodiversity Framework is the maintenance of genetic diversity in all species to safeguard their adaptive potential. To achieve this goal, a translational mindset, which aims to convert results of basic research into direct practical benefits, needs to be applied to biodiversity conservation. Despite much discussion on the value of genomics to conservation, a disconnect between those generating genomic resources and those applying it to biodiversity management remains. As global efforts to generate reference genomes for non-model species increase, investment into practical biodiversity applications is critically important. Applications such as understanding population and multispecies diversity and longitudinal monitoring need support alongside education for policymakers on integrating the data into evidence-based decisions. Without such investment, the opportunity to revolutionize global biodiversity conservation using genomics will not be fully realized.
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Affiliation(s)
- Carolyn J Hogg
- School of Life & Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.
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3
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Dai D, Xie C, Zhou Y, Bo D, Zhang S, Mao S, Liao Y, Cui S, Zhu Z, Wang X, Li F, Peng D, Zheng J, Sun M. Unzipped chromosome-level genomes reveal allopolyploid nematode origin pattern as unreduced gamete hybridization. Nat Commun 2023; 14:7156. [PMID: 37935661 PMCID: PMC10630426 DOI: 10.1038/s41467-023-42700-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/19/2023] [Indexed: 11/09/2023] Open
Abstract
The formation and consequences of polyploidization in animals with clonal reproduction remain largely unknown. Clade I root-knot nematodes (RKNs), characterized by parthenogenesis and allopolyploidy, show a widespread geographical distribution and extensive agricultural destruction. Here, we generated 4 unzipped polyploid RKN genomes and identified a putative novel alternative telomeric element. Then we reconstructed 4 chromosome-level assemblies and resolved their genome structures as AAB for triploid and AABB for tetraploid. The phylogeny of subgenomes revealed polyploid RKN origin patterns as hybridization between haploid and unreduced gametes. We also observed extensive chromosomal fusions and homologous gene expression decrease after polyploidization, which might offset the disadvantages of clonal reproduction and increase fitness in polyploid RKNs. Our results reveal a rare pathway of polyploidization in parthenogenic polyploid animals and provide a large number of high-precision genetic resources that could be used for RKN prevention and control.
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Affiliation(s)
- Dadong Dai
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chuanshuai Xie
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yayi Zhou
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dexin Bo
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shurong Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shengqiang Mao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yucheng Liao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Simeng Cui
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhaolu Zhu
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xueyu Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Fanling Li
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
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4
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Freitas S, Parker DJ, Labédan M, Dumas Z, Schwander T. Evidence for cryptic sex in parthenogenetic stick insects of the genus Timema. Proc Biol Sci 2023; 290:20230404. [PMID: 37727092 PMCID: PMC10509586 DOI: 10.1098/rspb.2023.0404] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 08/23/2023] [Indexed: 09/21/2023] Open
Abstract
Obligately parthenogenetic species are expected to be short lived since the lack of sex and recombination should translate into a slower adaptation rate and increased accumulation of deleterious alleles. Some, however, are thought to have been reproducing without males for millions of years. It is not clear how these old parthenogens can escape the predicted long-term costs of parthenogenesis, but an obvious explanation is cryptic sex. In this study, we screen for signatures of cryptic sex in eight populations of four parthenogenetic species of Timema stick insects, some estimated to be older than 1 Myr. Low genotype diversity, homozygosity of individuals and high linkage disequilibrium (LD) unaffected by marker distances support exclusively parthenogenetic reproduction in six populations. However, in two populations (namely, of the species Timema douglasi and T. monikensis) we find strong evidence for cryptic sex, most likely mediated by rare males. These populations had comparatively high genotype diversities, lower LD, and a clear LD decay with genetic distance. Rare sex in species that are otherwise largely parthenogenetic could help explain the unusual success of parthenogenesis in the Timema genus and raises the question whether episodes of rare sex are in fact the simplest explanation for the persistence of many old parthenogens in nature.
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Affiliation(s)
- Susana Freitas
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Darren J. Parker
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- School of Natural Sciences, Bangor University, Bangor, UK
| | - Marjorie Labédan
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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5
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Haider M, Schilling MP, Moest MH, Steiner FM, Schlick‐Steiner BC, Arthofer W. Evolutionary history of an Alpine Archaeognath ( Machilis pallida): Insights from different variant. Ecol Evol 2023; 13:e10227. [PMID: 37404697 PMCID: PMC10316371 DOI: 10.1002/ece3.10227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 05/31/2023] [Accepted: 06/09/2023] [Indexed: 07/06/2023] Open
Abstract
Reconstruction of species histories is a central aspect of evolutionary biology. Patterns of genetic variation within and among populations can be leveraged to elucidate evolutionary processes and demographic histories. However, interpreting genetic signatures and unraveling the contributing processes can be challenging, in particular for non-model organisms with complex reproductive modes and genome organization. One way forward is the combined consideration of patterns revealed by different molecular markers (nuclear vs. mitochondrial) and types of variants (common vs. rare) that differ in their age, mode, and rate of evolution. Here, we applied this approach to RNAseq data generated for Machilis pallida (Archaeognatha), an Alpine jumping bristletail considered parthenogenetic and triploid. We generated de novo transcriptome and mitochondrial assemblies to obtain high-density data to investigate patterns of mitochondrial and common and rare nuclear variation in 17 M. pallida individuals sampled from all known populations. We find that the different variant types capture distinct aspects of the evolutionary history and discuss the observed patterns in the context of parthenogenesis, polyploidy, and survival during glaciation. This study highlights the potential of different variant types to gain insights into evolutionary scenarios even from challenging but often available data and the suitability of M. pallida and the genus Machilis as a study system for the evolution of sexual strategies and polyploidization during environmental change. We also emphasize the need for further research which will be stimulated and facilitated by these newly generated resources and insights.
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Affiliation(s)
- Marlene Haider
- Department of Ecology, Molecular Ecology GroupUniversity of InnsbruckInnsbruckAustria
| | - Martin P. Schilling
- Department of Ecology, Molecular Ecology GroupUniversity of InnsbruckInnsbruckAustria
| | - Markus H. Moest
- Department of Ecology, Molecular Ecology GroupUniversity of InnsbruckInnsbruckAustria
| | - Florian M. Steiner
- Department of Ecology, Molecular Ecology GroupUniversity of InnsbruckInnsbruckAustria
| | | | - Wolfgang Arthofer
- Department of Ecology, Molecular Ecology GroupUniversity of InnsbruckInnsbruckAustria
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6
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Sperling AL, Glover DM. Parthenogenesis in dipterans: a genetic perspective. Proc Biol Sci 2023; 290:20230261. [PMID: 36946111 PMCID: PMC10031431 DOI: 10.1098/rspb.2023.0261] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
Parthenogenesis has been documented in almost every phylum of animals, and yet this phenomenon is largely understudied. It has particular importance in dipterans since some parthenogenetic species are also disease vectors and agricultural pests. Here, we present a catalogue of parthenogenetic dipterans, although it is likely that many more remain to be identified, and we discuss how their developmental biology and interactions with diverse environments may be linked to different types of parthenogenetic reproduction. We discuss how the advances in genetics and genomics have identified chromosomal loci associated with parthenogenesis. In particular, a polygenic cause of facultative parthenogenesis has been uncovered in Drosophila mercatorum, allowing the corresponding genetic variants to be tested for their ability to promote parthenogenesis in another species, Drosophila melanogaster. This study probably identifies just one of many routes that could be followed in the evolution of parthenogenesis. We attempt to account for why the phenomenon has evolved so many times in the dipteran order and why facultative parthenogenesis appears particularly prevalent. We also discuss the significance of coarse genomic changes, including non-disjunction, aneuploidy, and polyploidy and how, together with changes to specific genes, these might relate to both facultative and obligate parthenogenesis in dipterans and other parthenogenetic animals.
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Affiliation(s)
- A. L. Sperling
- Department of Genetics, University of Cambridge, Cambridge, UK
| | - D. M. Glover
- Department of Genetics, University of Cambridge, Cambridge, UK
- California Institute of Technology, Pasadena, CA, USA
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7
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Eleftheriadou N, Lubanga UK, Lefoe GK, Seehausen ML, Kenis M, Kavallieratos NG, Avtzis DN. Uncovering the Male Presence in Parthenogenetic Marchalina hellenica (Hemiptera: Marchalinidae): Insights into Its mtDNA Divergence and Reproduction Strategy. INSECTS 2023; 14:256. [PMID: 36975941 PMCID: PMC10059969 DOI: 10.3390/insects14030256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 02/24/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
Marchalina hellenica (Hemiptera: Marchalinidae), an endemic species in Greece and Turkey, is a major contributor to the annual honey production in its native range. However, in the areas that it invades, lacking natural enemies, it has detrimental effects on pine trees and potentially contributes to tree mortality. Although it was originally reported as thelytokous, males were later reported in Turkey and on several of the islands of Greece. To further disambiguate the exact parthenogenetic reproduction strategy of M. hellenica, we studied the emergence pattern of male individuals in Greece for two consecutive years (2021 and 2022). Furthermore, we examined the genetic variation among 15 geographically distant populations of M. hellenica in Greece using a mitochondrial DNA marker and compared the results with data from Turkey. The findings of this study document the existence of an additional M. hellenica population in its native range that repeatedly produces males, apart from the areas of Greece and Turkey in which they were initially reported, suggesting that males play a major, so far unknown role in the reproduction of this species. The populations in Greece and Turkey exhibited a strong genetic affinity, while human-aided dispersal seems to have obscured the genetic pattern acquired.
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Affiliation(s)
- Nikoleta Eleftheriadou
- Laboratory of Agricultural Zoology and Entomology, Faculty of Crop Science, Agricultural University of Athens, 75 Iera Odos str., 11855 Athens, Greece
| | - Umar K. Lubanga
- Agriculture Victoria, Department of Energy, Environment and Climate Action, AgriBio Centre, Bundoora, VIC 3083, Australia
| | - Greg K. Lefoe
- Agriculture Victoria, Department of Energy, Environment and Climate Action, AgriBio Centre, Bundoora, VIC 3083, Australia
| | - M. Lukas Seehausen
- Centre for Agriculture and Bioscience International, Rue des Grillons 1, 2800 Delémont, Switzerland
| | - Marc Kenis
- Centre for Agriculture and Bioscience International, Rue des Grillons 1, 2800 Delémont, Switzerland
| | - Nickolas G. Kavallieratos
- Laboratory of Agricultural Zoology and Entomology, Faculty of Crop Science, Agricultural University of Athens, 75 Iera Odos str., 11855 Athens, Greece
| | - Dimitrios N. Avtzis
- Forest Research Institute—Hellenic Agricultural Organization Demeter (HAO Demeter), Vassilika, 57006 Thessaloniki, Greece
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8
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Chen J, Du X, Xu X, Zhang S, Yao L, He X, Wang Y. Comparative Proteomic Analysis Provides New Insights into the Molecular Basis of Thermal-Induced Parthenogenesis in Silkworm ( Bombyx mori). INSECTS 2023; 14:insects14020134. [PMID: 36835703 PMCID: PMC9962255 DOI: 10.3390/insects14020134] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/14/2023] [Accepted: 01/19/2023] [Indexed: 05/27/2023]
Abstract
Artificial parthenogenetic induction via thermal stimuli in silkworm is an important technique that has been used in sericultural production. However, the molecular mechanism underlying it remains largely unknown. We have created a fully parthenogenetic line (PL) with more than 85% occurrence and 80% hatching rate via hot water treatment and genetic selection, while the parent amphigenetic line (AL) has less than 30% pigmentation rate and less than 1% hatching rate when undergoing the same treatment. Here, isobaric tags for relative and absolute quantitation (iTRAQ)-based analysis were used to investigate the key proteins and pathways associated with silkworm parthenogenesis. We uncovered the unique proteomic features of unfertilized eggs in PL. In total, 274 increased abundance proteins and 211 decreased abundance proteins were identified relative to AL before thermal induction. Function analysis displayed an increased level of translation and metabolism in PL. After thermal induction, 97 increased abundance proteins and 187 decreased abundance proteins were identified. An increase in stress response-related proteins and decrease in energy metabolism suggested that PL has a more effective response to buffer the thermal stress than AL. Cell cycle-related proteins, including histones, and spindle-related proteins were decreased in PL, indicating an important role of this decrease in the process of ameiotic parthenogenesis.
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Affiliation(s)
- Jine Chen
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xin Du
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xia Xu
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Sheng Zhang
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY 14853, USA
| | - Lusong Yao
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xiuling He
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yongqiang Wang
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
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9
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Forni G, Mikheyev AS, Luchetti A, Mantovani B. Gene transcriptional profiles in gonads of Bacillus taxa (Phasmida) with different cytological mechanisms of automictic parthenogenesis. ZOOLOGICAL LETTERS 2022; 8:14. [PMID: 36435814 PMCID: PMC9701443 DOI: 10.1186/s40851-022-00197-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 10/07/2022] [Indexed: 06/16/2023]
Abstract
The evolution of automixis - i.e., meiotic parthenogenesis - requires several features, including ploidy restoration after meiosis and maintenance of fertility. Characterizing the relative contribution of novel versus pre-existing genes and the similarities in their expression and sequence evolution is fundamental to understand the evolution of reproductive novelties. Here we identify gonads-biased genes in two Bacillus automictic stick-insects and compare their expression profile and sequence evolution with a bisexual congeneric species. The two parthenogens restore ploidy through different cytological mechanisms: in Bacillus atticus, nuclei derived from the first meiotic division fuse to restore a diploid egg nucleus, while in Bacillus rossius, diploidization occurs in some cells of the haploid blastula through anaphase restitution. Parthenogens' gonads transcriptional program is found to be largely assembled from genes that were already present before the establishment of automixis. The three species transcriptional profiles largely reflect their phyletic relationships, yet we identify a shared core of genes with gonad-biased patterns of expression in parthenogens which are either male gonads-biased in the sexual species or are not differentially expressed there. At the sequence level, just a handful of gonads-biased genes were inferred to have undergone instances of positive selection exclusively in the parthenogen species. This work is the first to explore the molecular underpinnings of automixis in a comparative framework: it delineates how reproductive novelties can be sustained by genes whose origin precedes the establishment of the novelty itself and shows that different meiotic mechanisms of reproduction can be associated with a shared molecular ground plan.
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Affiliation(s)
- Giobbe Forni
- Dip. Scienze Biologiche, Geologiche e Ambientali (BiGeA), University of Bologna, 40126, Bologna, Italy
- Dip. Scienze Agrarie e Ambientali, University of Milano, Milano, Italy
| | - Alexander S Mikheyev
- Australian National University, ACT, Canberra, 2600, Australia
- Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Okinawa, 904-0495, Japan
| | - Andrea Luchetti
- Dip. Scienze Biologiche, Geologiche e Ambientali (BiGeA), University of Bologna, 40126, Bologna, Italy.
| | - Barbara Mantovani
- Dip. Scienze Biologiche, Geologiche e Ambientali (BiGeA), University of Bologna, 40126, Bologna, Italy
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10
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da Cunha NL, Xue H, Wright SI, Barrett SCH. Genetic variation and clonal diversity in floating aquatic plants: Comparative genomic analysis of water hyacinth species in their native range. Mol Ecol 2022; 31:5307-5325. [PMID: 35984729 DOI: 10.1111/mec.16664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 07/24/2022] [Accepted: 08/10/2022] [Indexed: 12/15/2022]
Abstract
Many eukaryotic organisms reproduce by sexual and asexual reproduction. Genetic diversity in populations can be strongly dependent on the relative importance of these two reproductive modes. Here, we compare the amounts and patterns of genetic diversity in related water hyacinths that differ in their propensity for clonal propagation - highly clonal Eichhornia crassipes and moderately clonal E. azurea (Pontederiaceae). Our comparisons involved genotype-by-sequencing (GBS) of 137 E. crassipes ramets from 60 locations (193,495 nucleotide sites) and 118 E. azurea ramets from 53 locations (198,343 nucleotide sites) among six hydrological basins in central South America, the native range of both species. We predicted that because of more prolific clonal propagation, E. crassipes would exhibit lower clonal diversity than E. azurea. This prediction was supported by all measures of clonal diversity that we examined. Eichhornia crassipes also had a larger excess of heterozygotes at variant sites, another signature of clonality. However, genome-wide heterozygosity was not significantly different between the species. Eichhornia crassipes had weaker spatial genetic structure and lower levels of differentiation among hydrological basins than E. azurea, probably because of higher clonality and more extensive dispersal of its free-floating life form. Our findings for E. crassipes contrast with earlier studies from the invasive range which have reported very low levels of clonal diversity and extensive geographic areas of genetic uniformity.
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Affiliation(s)
- Nicolay Leme da Cunha
- Grupo de Ecología de la Polinización, INIBIOMA, CONICET-Universidad Nacional del Comahue, San Carlos de Bariloche, Rio Negro, Argentina.,Programa de Pós-Graduação em Ecologia e Conservação, Universidade Federal de Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Haoran Xue
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Stephen I Wright
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
| | - Spencer C H Barrett
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
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11
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Parker DJ, Jaron KS, Dumas Z, Robinson‐Rechavi M, Schwander T. X chromosomes show relaxed selection and complete somatic dosage compensation across
Timema
stick insect species. J Evol Biol 2022; 35:1734-1750. [PMID: 35933721 PMCID: PMC10087215 DOI: 10.1111/jeb.14075] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 05/06/2022] [Accepted: 07/14/2022] [Indexed: 11/29/2022]
Abstract
Sex chromosomes have evolved repeatedly across the tree of life. As they are present in different copy numbers in males and females, they are expected to experience different selection pressures than the autosomes, with consequences including a faster rate of evolution, increased accumulation of sexually antagonistic alleles and the evolution of dosage compensation. Whether these consequences are general or linked to idiosyncrasies of specific taxa is not clear as relatively few taxa have been studied thus far. Here, we use whole-genome sequencing to identify and characterize the evolution of the X chromosome in five species of Timema stick insects with XX:X0 sex determination. The X chromosome had a similar size (approximately 12% of the genome) and gene content across all five species, suggesting that the X chromosome originated prior to the diversification of the genus. Genes on the X showed evidence of relaxed selection (elevated dN/dS) and a slower evolutionary rate (dN + dS) than genes on the autosomes, likely due to sex-biased mutation rates. Genes on the X also showed almost complete dosage compensation in somatic tissues (heads and legs), but dosage compensation was absent in the reproductive tracts. Contrary to prediction, sex-biased genes showed little enrichment on the X, suggesting that the advantage X-linkage provides to the accumulation of sexually antagonistic alleles is weak. Overall, we found the consequences of X-linkage on gene sequences and expression to be similar across Timema species, showing the characteristics of the X chromosome are surprisingly consistent over 30 million years of evolution.
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Affiliation(s)
- Darren J. Parker
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
- School of Natural Sciences Bangor University Bangor UK
| | - Kamil S. Jaron
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
- School of Biological Sciences Institute of Evolutionary Biology University of Edinburgh Edinburgh UK
| | - Zoé Dumas
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
| | - Marc Robinson‐Rechavi
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
- Swiss Institute of Bioinformatics Lausanne Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
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Djordjevic J, Dumas Z, Robinson-Rechavi M, Schwander T, Parker DJ. Dynamics of sex-biased gene expression during development in the stick insect Timema californicum. Heredity (Edinb) 2022; 129:113-122. [PMID: 35581477 PMCID: PMC9338061 DOI: 10.1038/s41437-022-00536-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/04/2022] [Accepted: 04/06/2022] [Indexed: 12/03/2022] Open
Abstract
Sexually dimorphic phenotypes are thought to arise primarily from sex-biased gene expression during development. Major changes in developmental strategies, such as the shift from hemimetabolous to holometabolous development, are therefore expected to have profound consequences for the dynamics of sex-biased gene expression. However, no studies have previously examined sex-biased gene expression during development in hemimetabolous insects, precluding comparisons between developmental strategies. Here we characterized sex-biased gene expression at three developmental stages in a hemimetabolous stick insect (Timema californicum): hatchlings, juveniles, and adults. As expected, the proportion of sex-biased genes gradually increased during development, mirroring the gradual increase of phenotypic sexual dimorphism. Sex-biased genes identified at early developmental stages were generally consistently male- or female-biased at later stages, suggesting their importance in sexual differentiation. Additionally, we compared the dynamics of sex-biased gene expression during development in T. californicum to those of the holometabolous fly Drosophila melanogaster by reanalyzing publicly available RNA-seq data from third instar larval, pupal and adult stages. In D. melanogaster, 84% of genes were sex-biased at the adult stage (compared to only 20% in T. californicum), and sex-biased gene expression increased abruptly at the adult stage when morphological sexual dimorphism is manifested. Our findings are consistent with the prediction that the dynamics of sex-biased gene expression during development differ extensively between holometabolous and hemimetabolous insect species.
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Affiliation(s)
| | - Zoé Dumas
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Marc Robinson-Rechavi
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | - Darren James Parker
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
- Swiss Institute of Bioinformatics, Lausanne, Switzerland.
- School of Natural Sciences, Bangor University, Bangor, Gwynedd, United Kingdom.
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