scholarly journals Population genomics data supports introgression between western Iberian Squalius freshwater fish species

2019 ◽  
Author(s):  
Sofia L. Mendes ◽  
Maria M. Coelho ◽  
Vitor C. Sousa
Keyword(s):  
Gene Flow ◽  
Freshwater Fish ◽  
Population Genomics ◽  
Genotyping By Sequencing ◽  
Population Divergence ◽  
Freshwater Species ◽  
Genomic Approach ◽  
Demographic Modelling ◽  
Paraphyletic Group ◽  
First Time

AbstractIn freshwater fish, processes of population divergence and speciation are often linked to the geomorphology of rivers and lakes that isolate populations. However, current geographical isolation does not necessarily imply total absence of gene flow during the divergence process. Here, we focused on four species of the genus Squalius in Portuguese rivers: S. carolitertii, S. pyrenaicus, S. aradensis and S. torgalensis. Previous studies based on eight nuclear and mitochondrial markers revealed incongruent patterns, with nuclear loci suggesting that S. pyrenaicus was a paraphyletic group since its northern populations were genetically closer to S. carolitertii than to its southern populations. For the first time, we successfully applied a genomic approach to the study of the relationship between these species, using a Genotyping by Sequencing (GBS) approach. Our results revealed a species tree with two main lineages: (i) S. carolitertii and S. pyrenaicus; (ii) S. torgalensis and S. aradensis. Regarding S. carolitertii and S. pyrenaicus, we found evidence for past introgression between the two in the northern part of S. pyrenaicus distribution. This introgression reconciles previous mitochondrial and nuclear incongruent results and explains the apparent paraphyly of S. pyrenaicus. Our demographic modelling estimates are consistent across models, suggesting that the northern populations of S. pyrenaicus received a contribution of approximately 90% from S. carolitertii and 10% from southern S. pyrenaicus. This illustrates that even in freshwater species currently allopatric, we are able to detect past gene flow events in present-day genomes, suggesting speciation is more complex than simply allopatric.

scholarly journals Genomic signals found using RNA sequencing support conservation of walleye (Sander vitreus) in a large freshwater ecosystem

2020 ◽  
Author(s):  
Matt J. Thorstensen ◽  
Jennifer D. Jeffrey ◽  
Jason R. Treberg ◽  
Douglas A. Watkinson ◽  
Eva C. Enders ◽  
...  
Keyword(s):  
Rna Sequencing ◽  
Messenger Rna ◽  
Population Genomics ◽  
Large Female ◽  
Population Divergence ◽  
Freshwater Ecosystem ◽  
Sander Vitreus ◽  
Freshwater Species ◽  
Lake Winnipeg ◽  
Outlier Loci

AbstractRNA sequencing is an effective approach for studying an aquatic species with little prior molecular information available, yielding both physiological and genomic data, but its genetic applications are not well-characterized. We investigate this possible role for RNA sequencing for population genomics in Lake Winnipeg, Manitoba, Canada, walleye (Sander vitreus). Lake Winnipeg walleye represent the largest component of the second-largest freshwater fishery in Canada. In the present study, large female walleye were sampled via nonlethal gill biopsy over two years at three spawning sites representing a latitudinal gradient in the lake. Genetic variation from sequenced messenger RNA was analyzed for neutral and adaptive markers to investigate population structure and possible adaptive variation. We find low population divergence (FST = 0.0095), possible northward gene flow, and outlier loci that vary latitudinally in transcripts associated with cell membrane proteins and cytoskeletal function. These results indicate that Lake Winnipeg walleye may be effectively managed as a single demographically connected metapopulation with contributing subpopulations, and suggest genomic differences possibly underlying observed phenotypic differences. Because RNA sequencing data can yield physiological in addition to genetic information discussed here, we argue that it is useful for addressing diverse molecular questions in the conservation of freshwater species.

Statistical phylogeographic tests of competing 'Lake Carpentaria hypotheses' in the mouth-brooding freshwater fish, Glossamia aprion (Apogonidae)

2012 ◽  
Vol 63 (5) ◽  
pp. 450 ◽  
Author(s):  
Benjamin D. Cook ◽  
Mark Adams ◽  
Peter B. Mather ◽  
Jane M. Hughes
Keyword(s):  
Gene Flow ◽  
Freshwater Fish ◽  
Late Pleistocene ◽  
Marine Species ◽  
Relative Strength ◽  
Population Connectivity ◽  
Freshwater Species ◽  
Recent Period ◽  
Past Population ◽  
Diadromous Species

Glacial cycles during the Pleistocene reduced sea levels and created new land connections in northern Australia, where many currently isolated rivers also became connected via an extensive paleo-lake system, ‘Lake Carpentaria’. However, the most recent period during which populations of freshwater species were connected by gene flow across Lake Carpentaria is debated: various ‘Lake Carpentaria hypotheses’ have been proposed. Here, we used a statistical phylogeographic approach to assess the timing of past population connectivity across the Carpentaria region in the obligate freshwater fish, Glossamia aprion. Results for this species indicate that the most recent period of genetic exchange across the Carpentaria region coincided with the mid- to late Pleistocene, a result shown previously for other freshwater and diadromous species. Based on these findings and published studies for various freshwater, diadromous and marine species, we propose a set of ‘Lake Carpentaria’ hypotheses to explain past population connectivity in aquatic species: (1) strictly freshwater species had widespread gene flow in the mid- to late Pleistocene before the last glacial maximum; (2) marine species were subdivided into eastern and western populations by land during Pleistocene glacial phases; and (3) past connectivity in diadromous species reflects the relative strength of their marine affinity.

scholarly journals Adaptive Divergence under Gene Flow along an Environmental Gradient in Two Coexisting Stickleback Species

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 435
Author(s):  
Thijs M. P. Bal ◽  
Alejandro Llanos-Garrido ◽  
Anurag Chaturvedi ◽  
Io Verdonck ◽  
Bart Hellemans ◽  
...  
Keyword(s):  
Gene Flow ◽  
Brackish Water ◽  
Environmental Gradient ◽  
Spatial Scales ◽  
Morphological Differentiation ◽  
Genotyping By Sequencing ◽  
Adaptive Divergence ◽  
Linkage Groups ◽  
Closely Related Species ◽  
Genomic Patterns

There is a general and solid theoretical framework to explain how the interplay between natural selection and gene flow affects local adaptation. Yet, to what extent coexisting closely related species evolve collectively or show distinctive evolutionary responses remains a fundamental question. To address this, we studied the population genetic structure and morphological differentiation of sympatric three-spined and nine-spined stickleback. We conducted genotyping-by-sequencing and morphological trait characterisation using 24 individuals of each species from four lowland brackish water (LBW), four lowland freshwater (LFW) and three upland freshwater (UFW) sites in Belgium and the Netherlands. This combination of sites allowed us to contrast populations from isolated but environmentally similar locations (LFW vs. UFW), isolated but environmentally heterogeneous locations (LBW vs. UFW), and well-connected but environmentally heterogenous locations (LBW vs. LFW). Overall, both species showed comparable levels of genetic diversity and neutral genetic differentiation. However, for all three spatial scales, signatures of morphological and genomic adaptive divergence were substantially stronger among populations of the three-spined stickleback than among populations of the nine-spined stickleback. Furthermore, most outlier SNPs in the two species were associated with local freshwater sites. The few outlier SNPs that were associated with the split between brackish water and freshwater populations were located on one linkage group in three-spined stickleback and two linkage groups in nine-spined stickleback. We conclude that while both species show congruent evolutionary and genomic patterns of divergent selection, both species differ in the magnitude of their response to selection regardless of the geographical and environmental context.

scholarly journals Population genomics and haplotype analysis in spelt and bread wheat identifies a gene regulating glume color

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael Abrouk ◽  
Naveenkumar Athiyannan ◽  
Thomas Müller ◽  
Yveline Pailles ◽  
Christoph Stritt ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Candidate Gene ◽  
Population Genomics ◽  
Genotyping By Sequencing ◽  
Wheat Cultivars ◽  
Structural Variations ◽  
High Quality ◽  
Diversity Panel ◽  
Haplotype Variation ◽  
Single Region

AbstractThe cloning of agriculturally important genes is often complicated by haplotype variation across crop cultivars. Access to pan-genome information greatly facilitates the assessment of structural variations and rapid candidate gene identification. Here, we identified the red glume 1 (Rg-B1) gene using association genetics and haplotype analyses in ten reference grade wheat genomes. Glume color is an important trait to characterize wheat cultivars. Red glumes are frequent among Central European spelt, a dominant wheat subspecies in Europe before the 20th century. We used genotyping-by-sequencing to characterize a global diversity panel of 267 spelt accessions, which provided evidence for two independent introductions of spelt into Europe. A single region at the Rg-B1 locus on chromosome 1BS was associated with glume color in the diversity panel. Haplotype comparisons across ten high-quality wheat genomes revealed a MYB transcription factor as candidate gene. We found extensive haplotype variation across the ten cultivars, with a particular group of MYB alleles that was conserved in red glume wheat cultivars. Genetic mapping and transient infiltration experiments allowed us to validate this particular MYB transcription factor variants. Our study demonstrates the value of multiple high-quality genomes to rapidly resolve copy number and haplotype variations in regions controlling agriculturally important traits.

scholarly journals Up and Down the Blind Alley: Population Divergence with Scant Gene Flow in an Endangered Tropical Lineage of Andean Palms (Ceroxylon quindiuense Clade: Ceroxyloideae)

2017 ◽  
Vol 108 (3) ◽  
pp. 288-298 ◽  
Author(s):  
María José Sanín ◽  
Patricia Zapata ◽  
Jean-Christophe Pintaud ◽  
Gloria Galeano ◽  
Adriana Bohórquez ◽  
...  
Keyword(s):  
Gene Flow ◽  
Population Divergence ◽  
Blind Alley

Key Insights and Research Prospects at the Dawn of the Population Genomics Era for Verticillium dahliae

2021 ◽  
Vol 59 (1) ◽  
Author(s):  
Jie-Yin Chen ◽  
Steven J. Klosterman ◽  
Xiao-Ping Hu ◽  
Xiao-Feng Dai ◽  
Krishna V. Subbarao
Keyword(s):  
Population Structure ◽  
Verticillium Dahliae ◽  
Plant Pathogens ◽  
Population Genomics ◽  
Population Divergence ◽  
Annual Review ◽  
Publication Date ◽  
Disease Symptoms ◽  
Historical Perspectives ◽  
Characteristic Features

The genomics era has ushered in exciting possibilities to examine the genetic bases that undergird the characteristic features of Verticillium dahliae and other plant pathogens. In this review, we provide historical perspectives on some of the salient biological characteristics of V. dahliae, including its morphology, microsclerotia formation, host range, disease symptoms, vascular niche, reproduction, and population structure. The kaleidoscopic population structure of this pathogen is summarized, including different races of the pathogen, defoliating and nondefoliating phenotypes, vegetative compatibility groupings, and clonal populations. Where possible, we place the characteristic differences in the context of comparative and functional genomics analyses that have offered insights into population divergence within V. dahliae and the related species. Current challenges are highlighted along with some suggested future population genomics studies that will contribute to advancing our understanding of the population divergence in V. dahliae. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Population genomics reveals high gene flow in grass rockfish ( Sebastes rastrelliger )

2017 ◽  
Vol 33 ◽  
pp. 57-63 ◽  
Author(s):  
Edith Martinez ◽  
Vincent Buonaccorsi ◽  
John R. Hyde ◽  
Andres Aguilar
Keyword(s):  
Gene Flow ◽  
Population Genomics ◽  
High Gene Flow ◽  
High Gene

scholarly journals Spatial population genomics of a recent mosquito invasion

2020 ◽  
Author(s):  
Thomas L Schmidt ◽  
T. Swan ◽  
Jessica Chung ◽  
Stephan Karl ◽  
Samuel Demok ◽  
...  
Keyword(s):  
Gene Flow ◽  
Population Genomics ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Nucleotide Polymorphisms ◽  
Discrete Events ◽  
Long Distance ◽  
Population Genomic ◽  
Asian Tiger ◽  
Study Designs

AbstractPopulation genomic approaches can characterise dispersal across a single generation through to many generations in the past, bridging the gap between individual movement and intergenerational gene flow. These approaches are particularly useful when investigating dispersal in recently altered systems, where they provide a way of inferring long-distance dispersal between newly established populations and their interactions with existing populations. Human-mediated biological invasions represent such altered systems which can be investigated with appropriate study designs and analyses. Here we apply temporally-restricted sampling and a range of population genomic approaches to investigate dispersal in a 2004 invasion of Aedes albopictus (the Asian tiger mosquito) in the Torres Strait Islands (TSI) of Australia. We sampled mosquitoes from 13 TSI villages simultaneously and genotyped 373 mosquitoes at genome-wide single nucleotide polymorphisms (SNPs): 331 from the TSI, 36 from Papua New Guinea (PNG), and 4 incursive mosquitoes detected in uninvaded regions. Within villages, spatial genetic structure varied substantially but overall displayed isolation by distance and a neighbourhood size of 232–577. Close kin dyads revealed recent movement between islands 31–203 km apart, and deep learning inferences showed incursive Ae. albopictus had travelled to uninvaded regions from both adjacent and non-adjacent islands. Private alleles and a coancestry matrix indicated direct gene flow from PNG into nearby islands. Outlier analyses also detected four linked alleles introgressed from PNG, with the alleles surrounding 12 resistance-associated cytochrome P450 genes. By treating dispersal as both an intergenerational process and a set of discrete events, we describe a highly interconnected invasive system.

scholarly journals Differences in mate pairings of hatchery and natural origin coho salmon inferred from offspring genotypes

2021 ◽  
Author(s):  
H L Auld ◽  
D P Jacobson ◽  
A C Rhodes ◽  
M A Banks
Keyword(s):  
Mate Choice ◽  
Captive Breeding ◽  
Population Genomics ◽  
Coho Salmon ◽  
Genotyping By Sequencing ◽  
Nucleotide Polymorphisms ◽  
Single Nucleotide ◽  
Natural Origin ◽  
In Captivity ◽  
Genetic Level

Abstract Captive breeding can affect how sexual selection acts on subsequent generations. One context where this is important is in fish hatcheries. In many salmon hatcheries, spawning is controlled artificially and offspring are reared in captivity before release into the wild. While previous studies have suggested that hatchery and natural origin fish may make different mate choice decisions, it remains to be determined how hatchery fish may be making different mate choice decisions compared to natural origin fish at a genetic level. Using genotyping-by-sequencing (GBS), we identify single nucleotide polymorphisms (SNPs) associated with variation in mate pairings from a natural context involving hatchery and natural origin coho salmon (Oncorhynchus kisutch). In both natural origin and hatchery mate pairs, we observed more SNPs with negative assortment, than positive assortment. However, only 3% of the negative assortment SNPs were shared between the two mating groups, and 1% of the positive assortment SNPs were shared between the two mating groups, indicating divergence in mating cues between wild and hatchery raised salmon. These findings shed light on mate choice in general and may have important implications in the conservation management of species as well as for improving other captive breeding scenarios. There remains much to discover about mate choice in salmon and research described here reflects our intent to test the potential of ongoing advances in population genomics to develop new hatchery practices that may improve the performance of hatchery offspring, lessening the differences and thus potential impacts upon wild stocks.

scholarly journals Population genomics of parallel hybrid zones in the mimetic butterflies, H. melpomene and H. erato

2013 ◽  
Author(s):  
Nicola Nadeau ◽  
Mayte Ruiz ◽  
Patricio Salazar ◽  
Brian Counterman ◽  
Jose Alejandro Medina ◽  
...  
Keyword(s):  
Population Genomics ◽  
De Novo ◽  
Reference Sequence ◽  
Colour Pattern ◽  
Adaptive Divergence ◽  
Population Divergence ◽  
Hybrid Zones ◽  
Data Alignment ◽  
Parallel Hybrid ◽  
Genomic Regions

Hybrid zones can be valuable tools for studying evolution and identifying genomic regions responsible for adaptive divergence and underlying phenotypic variation. Hybrid zones between subspecies of Heliconius butterflies can be very narrow and are maintained by strong selection acting on colour pattern. The co-mimetic species H. erato and H. melpomene have parallel hybrid zones where both species undergo a change from one colour pattern form to another. We use restriction associated DNA sequencing to obtain several thousand genome wide sequence markers and use these to analyse patterns of population divergence across two pairs of parallel hybrid zones in Peru and Ecuador. We compare two approaches for analysis of this type of data; alignment to a reference genome and de novo assembly, and find that alignment gives the best results for species both closely (H. melpomene) and distantly (H. erato, ~15% divergent) related to the reference sequence. Our results confirm that the colour pattern controlling loci account for the majority of divergent regions across the genome, but we also detect other divergent regions apparently unlinked to colour pattern differences. We also use association mapping to identify previously unmapped colour pattern loci, in particular the Ro locus. Finally, we identify within our sample a new cryptic population of H. timareta in Ecuador, which occurs at relatively low altitude and is mimetic with H. melpomene malleti.

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