Bryan Thompson, Kamolphat Atsawawaranunt, Melissa C Nehmens, William S Pearman, E Owen Perkins, Pavel Pipek, Lee A Rollins, Hui Zhen Tan, Annabel Whibley, Anna W Santure, Katarina C Stuart
The expansion of human settlements over the past few centuries is responsible for an unprecedented number of invasive species introductions globally. An important component of biological invasion management is understanding how introduction history and postintroduction processes have jointly shaped present-day distributions and patterns of population structure, diversity and adaptation. One example of a successful invader is the European starling (Sturnus vulgaris), which was intentionally introduced to numerous countries in the 19th century, including Aotearoa New Zealand, where it has become firmly established. We used reduced representation sequencing to characterise the genetic population structure of the European starling in New Zealand, comparing it to that present in sampling locations in the native range and invasive Australian range. The population structure and genetic diversity patterns we found suggested restricted gene flow from the majority of New Zealand to the northmost sampling location (Auckland). We also profiled genetic bottlenecks and shared outlier genomic regions, which supported historical accounts of translocations between both Australian subpopulations and New Zealand, and provided evidence of which documented translocation events were more likely to have been successful. Using these results as well as historic demographic patterns, we demonstrate how genomic analysis complements even well-documented invasion histories to better understand invasion processes, with direct implications for understanding contemporary gene flow and informing invasion management.
{"title":"Population Genetics and Invasion History of the European Starling Across Aotearoa New Zealand.","authors":"Bryan Thompson, Kamolphat Atsawawaranunt, Melissa C Nehmens, William S Pearman, E Owen Perkins, Pavel Pipek, Lee A Rollins, Hui Zhen Tan, Annabel Whibley, Anna W Santure, Katarina C Stuart","doi":"10.1111/mec.17579","DOIUrl":"https://doi.org/10.1111/mec.17579","url":null,"abstract":"<p><p>The expansion of human settlements over the past few centuries is responsible for an unprecedented number of invasive species introductions globally. An important component of biological invasion management is understanding how introduction history and postintroduction processes have jointly shaped present-day distributions and patterns of population structure, diversity and adaptation. One example of a successful invader is the European starling (Sturnus vulgaris), which was intentionally introduced to numerous countries in the 19th century, including Aotearoa New Zealand, where it has become firmly established. We used reduced representation sequencing to characterise the genetic population structure of the European starling in New Zealand, comparing it to that present in sampling locations in the native range and invasive Australian range. The population structure and genetic diversity patterns we found suggested restricted gene flow from the majority of New Zealand to the northmost sampling location (Auckland). We also profiled genetic bottlenecks and shared outlier genomic regions, which supported historical accounts of translocations between both Australian subpopulations and New Zealand, and provided evidence of which documented translocation events were more likely to have been successful. Using these results as well as historic demographic patterns, we demonstrate how genomic analysis complements even well-documented invasion histories to better understand invasion processes, with direct implications for understanding contemporary gene flow and informing invasion management.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17579"},"PeriodicalIF":4.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashley C Love, Mia L Nahom, Jessica Gutierrez, Lauren Albert, Sarah A Knutie
Gut microbiota regulate multiple aspects of host health, including metabolism and the development of the immune system. However, we still know relatively little about how the gut microbiota influences host responses to parasitism in wild organisms, particularly whether host-microbiota interactions contribute to variation in parasitism across host species. The goal of this study was to determine the role of gut microbiota in shaping how birds respond to nest parasites and investigate whether this relationship varies between host species. Both eastern bluebirds (Sialia sialis) and tree swallows (Tachycineta bicolor) are parasitized by blow flies (Protocalliphora sialia), for which larval flies feed on nestlings' blood. We experimentally manipulated the gut microbiota of nestling bluebirds and tree swallows by dosing nestlings with an oral antibiotic or sterile water as a control. We then quantified nestling physiology (haemoglobin, glucose, parasite-specific IgY antibody levels), body morphometrics, and survival until fledging, as well as blow fly abundance and size. An experimental disruption of nestling gut microbiota increased parasite abundance in tree swallows, but decreased parasite abundance in bluebirds, which suggests that the disruption has opposing effects on resistance across host species. Furthermore, experimental treatment delayed parasite development and had variable effects on nestling body morphometrics and physiology across the two host species. Together, these results suggest that gut microbiota contribute to host differences in resistance to blow flies and can influence host-parasite interactions.
{"title":"An Early-Life Disruption of Gut Microbiota Has Opposing Effects on Parasite Resistance in Two Host Species.","authors":"Ashley C Love, Mia L Nahom, Jessica Gutierrez, Lauren Albert, Sarah A Knutie","doi":"10.1111/mec.17595","DOIUrl":"https://doi.org/10.1111/mec.17595","url":null,"abstract":"<p><p>Gut microbiota regulate multiple aspects of host health, including metabolism and the development of the immune system. However, we still know relatively little about how the gut microbiota influences host responses to parasitism in wild organisms, particularly whether host-microbiota interactions contribute to variation in parasitism across host species. The goal of this study was to determine the role of gut microbiota in shaping how birds respond to nest parasites and investigate whether this relationship varies between host species. Both eastern bluebirds (Sialia sialis) and tree swallows (Tachycineta bicolor) are parasitized by blow flies (Protocalliphora sialia), for which larval flies feed on nestlings' blood. We experimentally manipulated the gut microbiota of nestling bluebirds and tree swallows by dosing nestlings with an oral antibiotic or sterile water as a control. We then quantified nestling physiology (haemoglobin, glucose, parasite-specific IgY antibody levels), body morphometrics, and survival until fledging, as well as blow fly abundance and size. An experimental disruption of nestling gut microbiota increased parasite abundance in tree swallows, but decreased parasite abundance in bluebirds, which suggests that the disruption has opposing effects on resistance across host species. Furthermore, experimental treatment delayed parasite development and had variable effects on nestling body morphometrics and physiology across the two host species. Together, these results suggest that gut microbiota contribute to host differences in resistance to blow flies and can influence host-parasite interactions.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17595"},"PeriodicalIF":4.5,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142685479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Connor M French, Roberta P Damasceno, Mariana M Vasconcellos, Miguel T Rodrigues, Ana C Carnaval, Michael J Hickerson
In integrative distributional, demographic and coalescent (iDDC) modelling, a critical component is the statistical relationship between habitat suitability and local population sizes. This study explores this relationship in two Enyalius lizard species from the Brazilian Atlantic Forest: the high-elevation E. iheringii and low-elevation E. catenatus and how this transformation affects spatiotemporal demographic inference. Most previous iDDC studies assumed a linear relationship, but this study hypothesises that the relationship may be nonlinear, especially for high-elevation species with broader environmental tolerances. We test two key hypotheses: (1) The habitat suitability to population size relationship is nonlinear for E. iheringii (high-elevation) and linear for E. catenatus (low-elevation); and (2) E. iheringii exhibits higher effective migration across populations than E. catenatus. Our findings provide clear support for hypothesis (2), but mixed support for hypothesis (1), with strong model support for a nonlinear transformation in the high-elevation E. iheringii and some (albeit weak) support for a nonlinear transformation also in E. catenatus. The iDDC models allow us to generate landscape-wide maps of predicted genetic diversity for both species, revealing that genetic diversity predictions for the high-elevation E. iheringii align with estimated patterns of historical range stability, whereas predictions for low-elevation E. catenatus are distinct from range-wide stability predictions. This research highlights the importance of accurately modelling the habitat suitability to population size relationship in iDDC studies, contributing to our understanding of species' demographic responses to environmental changes.
在综合分布、人口和聚合(iDDC)建模中,栖息地适宜性与当地种群数量之间的统计关系是一个关键组成部分。本研究探讨了巴西大西洋森林中两个Enyalius蜥蜴物种(高海拔的E. iheringii和低海拔的E. catenatus)的这种关系,以及这种转变如何影响时空人口推断。之前的大多数 iDDC 研究都假定两者之间存在线性关系,但本研究假设两者之间可能存在非线性关系,尤其是对环境耐受性更强的高海拔物种而言。我们检验了两个关键假设:(1)E. iheringii(高海拔)的栖息地适宜性与种群数量的关系是非线性的,而 E. catenatus(低海拔)的栖息地适宜性与种群数量的关系是线性的;(2)E. iheringii比 E. catenatus表现出更高的种群间有效迁移。我们的研究结果为假设(2)提供了明确的支持,但为假设(1)提供了不同的支持,高海拔 E. iheringii 的非线性变化得到了模型的有力支持,E. catenatus 的非线性变化也得到了一些支持(尽管很弱)。iDDC 模型允许我们生成这两个物种的全地貌遗传多样性预测图,揭示了高海拔 E. iheringii 的遗传多样性预测与历史分布区稳定性的估计模式一致,而低海拔 E. catenatus 的预测则与全分布区稳定性预测不同。这项研究强调了在 iDDC 研究中准确模拟栖息地适宜性与种群数量关系的重要性,有助于我们了解物种对环境变化的人口响应。
{"title":"Elevational Range Impacts Connectivity and Predicted Deme Sizes From Models of Habitat Suitability.","authors":"Connor M French, Roberta P Damasceno, Mariana M Vasconcellos, Miguel T Rodrigues, Ana C Carnaval, Michael J Hickerson","doi":"10.1111/mec.17593","DOIUrl":"https://doi.org/10.1111/mec.17593","url":null,"abstract":"<p><p>In integrative distributional, demographic and coalescent (iDDC) modelling, a critical component is the statistical relationship between habitat suitability and local population sizes. This study explores this relationship in two Enyalius lizard species from the Brazilian Atlantic Forest: the high-elevation E. iheringii and low-elevation E. catenatus and how this transformation affects spatiotemporal demographic inference. Most previous iDDC studies assumed a linear relationship, but this study hypothesises that the relationship may be nonlinear, especially for high-elevation species with broader environmental tolerances. We test two key hypotheses: (1) The habitat suitability to population size relationship is nonlinear for E. iheringii (high-elevation) and linear for E. catenatus (low-elevation); and (2) E. iheringii exhibits higher effective migration across populations than E. catenatus. Our findings provide clear support for hypothesis (2), but mixed support for hypothesis (1), with strong model support for a nonlinear transformation in the high-elevation E. iheringii and some (albeit weak) support for a nonlinear transformation also in E. catenatus. The iDDC models allow us to generate landscape-wide maps of predicted genetic diversity for both species, revealing that genetic diversity predictions for the high-elevation E. iheringii align with estimated patterns of historical range stability, whereas predictions for low-elevation E. catenatus are distinct from range-wide stability predictions. This research highlights the importance of accurately modelling the habitat suitability to population size relationship in iDDC studies, contributing to our understanding of species' demographic responses to environmental changes.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17593"},"PeriodicalIF":4.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Michael C. Whitlock-Recipient of the 2024 Molecular Ecology Prize.","authors":"Sam Yeaman","doi":"10.1111/mec.17598","DOIUrl":"https://doi.org/10.1111/mec.17598","url":null,"abstract":"","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17598"},"PeriodicalIF":4.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142680161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Josephine R Paris, R Andrew King, Joan Ferrer Obiol, Sophie Shaw, Anke Lange, Vincent Bourret, Patrick B Hamilton, Darren Rowe, Lauren V Laing, Audrey Farbos, Karen Moore, Mauricio A Urbina, Ronny van Aerle, Julian M Catchen, Rod W Wilson, Nicolas R Bury, Eduarda M Santos, Jamie R Stevens
Industrial pollution is a major driver of ecosystem degradation, but it can also act as a driver of contemporary evolution. As a result of intense mining activity during the Industrial Revolution, several rivers across the southwest of England are polluted with high concentrations of metals. Despite the documented negative impacts of ongoing metal pollution, brown trout (Salmo trutta L.) survive and thrive in many of these metal-impacted rivers. We used population genomics, transcriptomics, and metal burdens to investigate the genomic and transcriptomic signatures of potential metal tolerance. RADseq analysis of six populations (originating from three metal-impacted and three control rivers) revealed strong genetic substructuring between impacted and control populations. We identified selection signatures at 122 loci, including genes related to metal homeostasis and oxidative stress. Trout sampled from metal-impacted rivers exhibited significantly higher tissue concentrations of cadmium, copper, nickel and zinc, which remained elevated after 11 days in metal-free water. After depuration, we used RNAseq to quantify gene expression differences between metal-impacted and control trout, identifying 2042 differentially expressed genes (DEGs) in the gill, and 311 DEGs in the liver. Transcriptomic signatures in the gill were enriched for genes involved in ion transport processes, metal homeostasis, oxidative stress, hypoxia, and response to xenobiotics. Our findings reveal shared genomic and transcriptomic pathways involved in detoxification, oxidative stress responses and ion regulation. Overall, our results demonstrate the diverse effects of metal pollution in shaping both neutral and adaptive genetic variation, whilst also highlighting the potential role of constitutive gene expression in promoting metal tolerance.
{"title":"The Genomic Signature and Transcriptional Response of Metal Tolerance in Brown Trout Inhabiting Metal-Polluted Rivers.","authors":"Josephine R Paris, R Andrew King, Joan Ferrer Obiol, Sophie Shaw, Anke Lange, Vincent Bourret, Patrick B Hamilton, Darren Rowe, Lauren V Laing, Audrey Farbos, Karen Moore, Mauricio A Urbina, Ronny van Aerle, Julian M Catchen, Rod W Wilson, Nicolas R Bury, Eduarda M Santos, Jamie R Stevens","doi":"10.1111/mec.17591","DOIUrl":"10.1111/mec.17591","url":null,"abstract":"<p><p>Industrial pollution is a major driver of ecosystem degradation, but it can also act as a driver of contemporary evolution. As a result of intense mining activity during the Industrial Revolution, several rivers across the southwest of England are polluted with high concentrations of metals. Despite the documented negative impacts of ongoing metal pollution, brown trout (Salmo trutta L.) survive and thrive in many of these metal-impacted rivers. We used population genomics, transcriptomics, and metal burdens to investigate the genomic and transcriptomic signatures of potential metal tolerance. RADseq analysis of six populations (originating from three metal-impacted and three control rivers) revealed strong genetic substructuring between impacted and control populations. We identified selection signatures at 122 loci, including genes related to metal homeostasis and oxidative stress. Trout sampled from metal-impacted rivers exhibited significantly higher tissue concentrations of cadmium, copper, nickel and zinc, which remained elevated after 11 days in metal-free water. After depuration, we used RNAseq to quantify gene expression differences between metal-impacted and control trout, identifying 2042 differentially expressed genes (DEGs) in the gill, and 311 DEGs in the liver. Transcriptomic signatures in the gill were enriched for genes involved in ion transport processes, metal homeostasis, oxidative stress, hypoxia, and response to xenobiotics. Our findings reveal shared genomic and transcriptomic pathways involved in detoxification, oxidative stress responses and ion regulation. Overall, our results demonstrate the diverse effects of metal pollution in shaping both neutral and adaptive genetic variation, whilst also highlighting the potential role of constitutive gene expression in promoting metal tolerance.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17591"},"PeriodicalIF":4.5,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying Chen, Song Tan, Qiwei Xu, Jinzhong Fu, Yin Qi, Xia Qiu, Weizhao Yang
How divergence occurs between closely related organisms in the absence of geographic barriers to gene flow stands as one of the long-standing questions in evolutionary biology. Previous studies suggested that the interplay between selection, gene flow and recombination strongly affected the process of divergence with gene flow. However, the extent to which these forces interact to drive divergence remains largely ambiguous. Guinan toad-headed lizards (Phrynocephalus guinanensis) in the Mugetan Desert exhibit striking colour differences from lizards outside the desert and provide an excellent model to address this question. Through extensive sampling and whole genome sequencing, we obtained genotypes for 191 samples from 14 populations inside and outside the desert. Despite the colour differences, continuous and asymmetric gene flow was detected across the desert border. More importantly, 273 highly diverged regions (HDRs) were identified between them, accounting only for 0.47% of the genome but widely distributed across 20 (out of the total 24) chromosomes. Strong signatures of selection were identified in HDRs, and local recombination rates were repressed. Furthermore, five HDRs exhibited significantly higher divergence, which contained key genes associated with crucial functions in animal coloration, including pteridine and melanocyte pigmentation. Genes related to retinal cells and steroid hormones were identified in other HDRs, which might have also contributed to the formation of colour variation in the presence of gene flow. This study provided novel insights into the understanding of the evolutionary mechanisms of genetic divergence in the presence of gene flow.
{"title":"Genomic Architecture Underlying the Striking Colour Variation in the Presence of Gene Flow for the Guinan Toad-Headed Lizard.","authors":"Ying Chen, Song Tan, Qiwei Xu, Jinzhong Fu, Yin Qi, Xia Qiu, Weizhao Yang","doi":"10.1111/mec.17594","DOIUrl":"https://doi.org/10.1111/mec.17594","url":null,"abstract":"<p><p>How divergence occurs between closely related organisms in the absence of geographic barriers to gene flow stands as one of the long-standing questions in evolutionary biology. Previous studies suggested that the interplay between selection, gene flow and recombination strongly affected the process of divergence with gene flow. However, the extent to which these forces interact to drive divergence remains largely ambiguous. Guinan toad-headed lizards (Phrynocephalus guinanensis) in the Mugetan Desert exhibit striking colour differences from lizards outside the desert and provide an excellent model to address this question. Through extensive sampling and whole genome sequencing, we obtained genotypes for 191 samples from 14 populations inside and outside the desert. Despite the colour differences, continuous and asymmetric gene flow was detected across the desert border. More importantly, 273 highly diverged regions (HDRs) were identified between them, accounting only for 0.47% of the genome but widely distributed across 20 (out of the total 24) chromosomes. Strong signatures of selection were identified in HDRs, and local recombination rates were repressed. Furthermore, five HDRs exhibited significantly higher divergence, which contained key genes associated with crucial functions in animal coloration, including pteridine and melanocyte pigmentation. Genes related to retinal cells and steroid hormones were identified in other HDRs, which might have also contributed to the formation of colour variation in the presence of gene flow. This study provided novel insights into the understanding of the evolutionary mechanisms of genetic divergence in the presence of gene flow.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17594"},"PeriodicalIF":4.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142643567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When a species invades a novel environment, it must bridge the environment-phenotype mismatch in its new range to persist. Contemporary invasion biology research has focused on the role that trait variation and adaptation, and their underlying genomic factors, play in a species' adaptive potential, and thus facilitating invasion. Empirical studies have provided valuable insights into phenotypes that persist and arise in novel environments, coupled with 'omics tools that further the understanding of the contributions of genomic architecture in species establishment. Particularly, the use of transcriptomics to explore the role of plasticity in the initial stages of an invasion is growing. Here, we assess the role of various mechanisms relating to regulation and functional adaptation (often measured via the transcriptome) that support trait-specific plasticity in invasive species, allowing phenotypic variability without directly altering genomic diversity. First, we present a comprehensive review of the studies utilising transcriptomics in invasion biology. Second, we collate the evidence for and against the role of a range of regulatory processes in contributing to invasive species plasticity. Finally, we pose open questions in invasion biology where the use of transcriptome data may be valuable, as well as discuss the methodological limitations.
{"title":"Can Transcriptomics Elucidate the Role of Regulation in Invasion Success?","authors":"Amy L Vaughan, Manpreet K Dhami","doi":"10.1111/mec.17583","DOIUrl":"10.1111/mec.17583","url":null,"abstract":"<p><p>When a species invades a novel environment, it must bridge the environment-phenotype mismatch in its new range to persist. Contemporary invasion biology research has focused on the role that trait variation and adaptation, and their underlying genomic factors, play in a species' adaptive potential, and thus facilitating invasion. Empirical studies have provided valuable insights into phenotypes that persist and arise in novel environments, coupled with 'omics tools that further the understanding of the contributions of genomic architecture in species establishment. Particularly, the use of transcriptomics to explore the role of plasticity in the initial stages of an invasion is growing. Here, we assess the role of various mechanisms relating to regulation and functional adaptation (often measured via the transcriptome) that support trait-specific plasticity in invasive species, allowing phenotypic variability without directly altering genomic diversity. First, we present a comprehensive review of the studies utilising transcriptomics in invasion biology. Second, we collate the evidence for and against the role of a range of regulatory processes in contributing to invasive species plasticity. Finally, we pose open questions in invasion biology where the use of transcriptome data may be valuable, as well as discuss the methodological limitations.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17583"},"PeriodicalIF":4.5,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sean M Keogh, Nathan A Johnson, Chase H Smith, Bernard E Sietman, Jeffrey T Garner, Charles R Randklev, Andrew M Simons
The isolated river drainages of eastern North America serve as a natural laboratory to investigate the roles of allopatry and secondary contact in the evolutionary trajectories of recently diverged lineages. Drainage divides facilitate allopatric speciation, but due to their sensitivity to climatic and geomorphological changes, neighboring rivers frequently coalesce, creating recurrent opportunities of isolation and contact throughout the history of aquatic lineages. The freshwater mussel Quadrula quadrula is widely distributed across isolated rivers of eastern North America and possesses high phenotypic and molecular variation across its range. We integrate sequence data from three genomes, including female- and male-inherited mitochondrial markers and thousands of nuclear encoded SNPs with morphology and geography to illuminate the group's divergence history. Across contemporary isolated rivers, we found continuums of molecular and morphological variation, following a pattern of isolation by distance. In contact zones, hybridization was frequent with no apparent fitness consequences, as advanced hybrids were common. Accordingly, we recognize Q. quadrula as a single cohesive species with subspecific variation (Q. quadrula rumphiana). Demographic modeling and divergence dating supported a divergence history characterized by allopatric vicariance followed by secondary contact, likely driven by river rearrangements and Pleistocene glacial cycles. Despite clinal range-wide variation and hybridization in contact zones, the process-based species delimitation tool delimitR, which considers demographic scenarios like secondary contact, supported the delimitation of the maximum number of species tested. As such, when interpreting species delimitation results, we suggest careful consideration of spatial sampling and subsequent geographic patterns of biological variation, particularly for wide-ranging taxa.
{"title":"Secondary contact erodes Pleistocene diversification in a wide-ranging freshwater mussel (Quadrula).","authors":"Sean M Keogh, Nathan A Johnson, Chase H Smith, Bernard E Sietman, Jeffrey T Garner, Charles R Randklev, Andrew M Simons","doi":"10.1111/mec.17572","DOIUrl":"10.1111/mec.17572","url":null,"abstract":"<p><p>The isolated river drainages of eastern North America serve as a natural laboratory to investigate the roles of allopatry and secondary contact in the evolutionary trajectories of recently diverged lineages. Drainage divides facilitate allopatric speciation, but due to their sensitivity to climatic and geomorphological changes, neighboring rivers frequently coalesce, creating recurrent opportunities of isolation and contact throughout the history of aquatic lineages. The freshwater mussel Quadrula quadrula is widely distributed across isolated rivers of eastern North America and possesses high phenotypic and molecular variation across its range. We integrate sequence data from three genomes, including female- and male-inherited mitochondrial markers and thousands of nuclear encoded SNPs with morphology and geography to illuminate the group's divergence history. Across contemporary isolated rivers, we found continuums of molecular and morphological variation, following a pattern of isolation by distance. In contact zones, hybridization was frequent with no apparent fitness consequences, as advanced hybrids were common. Accordingly, we recognize Q. quadrula as a single cohesive species with subspecific variation (Q. quadrula rumphiana). Demographic modeling and divergence dating supported a divergence history characterized by allopatric vicariance followed by secondary contact, likely driven by river rearrangements and Pleistocene glacial cycles. Despite clinal range-wide variation and hybridization in contact zones, the process-based species delimitation tool delimitR, which considers demographic scenarios like secondary contact, supported the delimitation of the maximum number of species tested. As such, when interpreting species delimitation results, we suggest careful consideration of spatial sampling and subsequent geographic patterns of biological variation, particularly for wide-ranging taxa.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17572"},"PeriodicalIF":4.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tsering C L Chan, Boris Yagound, Gregory P Brown, Harrison J F Eyck, Richard Shine, Lee A Rollins
Parasites may suppress the immune function of infected hosts using microRNAs (miRNAs) to prevent protein production. Nonetheless, little is known about the diversity of miRNAs and their mode(s) of action. In this study, we investigated the effects of infection by a parasitic lungworm (Rhabdias pseudosphaerocephala) on miRNA and mRNA expression of its host, the invasive cane toad (Rhinella marina). To investigate the cane toad's innate and adaptive immune response to this parasite, we compared miRNA and mRNA expression in naïve toads that had never been infected by lungworms to toads that were infected with lungworms for the first time in their lives, and toads that were infected the second time in their lives (i.e., had two consecutive infections). In total, we identified 101 known miRNAs and 86 potential novel miRNAs. Compared to uninfected and single-infection toads, multiple-infection animals drastically downregulated three miRNAs. These miRNAs were associated with gene pathways related to the immune response, potentially reflecting the immunosuppression of cane toads by their parasites. Infected hosts did not respond with substantially differential mRNA transcription; only one gene was differentially expressed between control and single-infection hosts. Our study suggests that miRNA may play an important role in mediating host-parasite interactions in a system in which an ongoing range expansion by the host has generated substantial divergence in host-parasite interactions.
{"title":"Infection by the Lungworm Rhabdias pseudosphaerocephala Affects the Expression of Immune-Related microRNAs by Its Co-Evolved Host, the Cane Toad Rhinella marina.","authors":"Tsering C L Chan, Boris Yagound, Gregory P Brown, Harrison J F Eyck, Richard Shine, Lee A Rollins","doi":"10.1111/mec.17587","DOIUrl":"10.1111/mec.17587","url":null,"abstract":"<p><p>Parasites may suppress the immune function of infected hosts using microRNAs (miRNAs) to prevent protein production. Nonetheless, little is known about the diversity of miRNAs and their mode(s) of action. In this study, we investigated the effects of infection by a parasitic lungworm (Rhabdias pseudosphaerocephala) on miRNA and mRNA expression of its host, the invasive cane toad (Rhinella marina). To investigate the cane toad's innate and adaptive immune response to this parasite, we compared miRNA and mRNA expression in naïve toads that had never been infected by lungworms to toads that were infected with lungworms for the first time in their lives, and toads that were infected the second time in their lives (i.e., had two consecutive infections). In total, we identified 101 known miRNAs and 86 potential novel miRNAs. Compared to uninfected and single-infection toads, multiple-infection animals drastically downregulated three miRNAs. These miRNAs were associated with gene pathways related to the immune response, potentially reflecting the immunosuppression of cane toads by their parasites. Infected hosts did not respond with substantially differential mRNA transcription; only one gene was differentially expressed between control and single-infection hosts. Our study suggests that miRNA may play an important role in mediating host-parasite interactions in a system in which an ongoing range expansion by the host has generated substantial divergence in host-parasite interactions.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17587"},"PeriodicalIF":4.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Natural Hybrid Zone of Swordtails Reveals Molecular Insights Into the Adaptive Genomic Basis of Thermal Tolerance.","authors":"Carina M Lai, Brenna C M Stanford, Sean M Rogers","doi":"10.1111/mec.17584","DOIUrl":"https://doi.org/10.1111/mec.17584","url":null,"abstract":"","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17584"},"PeriodicalIF":4.5,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142613280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}