scholarly journals Genome-wide mapping in a house mouse hybrid zone reveals hybrid sterility loci and Dobzhansky-Muller interactions

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Leslie M Turner ◽  
Bettina Harr
Keyword(s):  
House Mouse ◽  
Hybrid Zone ◽  
Hybrid Sterility ◽  
Testis Weight ◽  
Hybrid Zones ◽  
Incipient Species ◽  
Complex Interactions ◽  
Genetic Mechanisms ◽  
Resolution Mapping ◽  
Genomic Regions

Mapping hybrid defects in contact zones between incipient species can identify genomic regions contributing to reproductive isolation and reveal genetic mechanisms of speciation. The house mouse features a rare combination of sophisticated genetic tools and natural hybrid zones between subspecies. Male hybrids often show reduced fertility, a common reproductive barrier between incipient species. Laboratory crosses have identified sterility loci, but each encompasses hundreds of genes. We map genetic determinants of testis weight and testis gene expression using offspring of mice captured in a hybrid zone between M. musculus musculus and M. m. domesticus. Many generations of admixture enables high-resolution mapping of loci contributing to these sterility-related phenotypes. We identify complex interactions among sterility loci, suggesting multiple, non-independent genetic incompatibilities contribute to barriers to gene flow in the hybrid zone.

scholarly journals Genome-Wide Mapping In A House Mouse Hybrid Zone Reveals Hybrid Sterility Loci And Dobzhansky-Muller Interactions

2014 ◽  
Author(s):  
Leslie Turner ◽  
Bettina Harr
Keyword(s):  
House Mouse ◽  
Hybrid Zone ◽  
Hybrid Sterility ◽  
Testis Weight ◽  
Hybrid Zones ◽  
Incipient Species ◽  
Complex Interactions ◽  
Genetic Mechanisms ◽  
Resolution Mapping ◽  
Genomic Regions

Mapping hybrid defects in contact zones between incipient species can identify genomic regions contributing to reproductive isolation and reveal genetic mechanisms of speciation. The house mouse features a rare combination of sophisticated genetic tools and natural hybrid zones between subspecies. Male hybrids often show reduced fertility, a common reproductive barrier between incipient species. Laboratory crosses have identified sterility loci, but each encompasses hundreds of genes. We map genetic determinants of testis weight and testis gene expression using offspring of mice captured in a hybrid zone between M. musculus musculus and M. m. domesticus. Many generations of admixture enables high-resolution mapping of loci contributing to these sterility-related phenotypes. We identify complex interactions among sterility loci, suggesting multiple, non-independent genetic incompatibilities contribute to barriers to gene flow in the hybrid zone.

scholarly journals Copy number variation of the putative speciation genes in the European house mouse hybrid zone

2021 ◽  
Author(s):  
Alexey Yanchukov ◽  
Zusana Hiadlovska ◽  
Zeljka Pezer ◽  
Milos Macholan ◽  
Jaroslav Pialek ◽  
...  
Keyword(s):  
Copy Number Variation ◽  
House Mouse ◽  
Hybrid Zone ◽  
Copy Number ◽  
Digital Pcr ◽  
Gene Copy ◽  
Ancestral Population ◽  
Hybrid Zones ◽  
Interaction Sites ◽  
Number Variation

Hybrid zones have long been described as "windows on the evolutionary process", and studying them has become even more important since the advance in the genome analysis tools. The hybrid zone between two subspecies of the house mouse (Mus musculus musculus and Mus m. domesticus) is a unique model speciation system to study fine scale interactions of recently diverged genomes. Here, we explore the role of gene Copy Number Variation in shaping the barrier to introgression in the hybrid zone within a previously established transect in Central Europe. The CNV of seven pre-selected candidate genes was determined via droplet-digital PCR and analyzed in the context of ~500k SNPs, with the ancestral population (i.e. musculus or domesticus) of every SNP allele previously inferred in the admixed individuals (Baird et al., in prep.). The copy numbers of five genes were clearly associated with the prevalence of either musculus or domesticus genomes across the hybrid zone. In three cases, the highest and/or outlying levels of association were observed at or very close to the annotated positions of the respective gene amplicons, demonstrating the power of our approach in confirming the reference locations of copy number variants. Notably, several other reference locations were recognized as positive outliers in the association with particular CNV genes, possibly representing the extra gene copies and/or their epistatic interaction sites.

scholarly journals Persistence of a Geographically-Stable Hybrid Zone in Puerto Rican Dwarf Geckos

2019 ◽  
Vol 110 (5) ◽  
pp. 523-534 ◽  
Author(s):  
Brendan J Pinto ◽  
James Titus-McQuillan ◽  
Juan D Daza ◽  
Tony Gamble
Keyword(s):  
Reproductive Isolation ◽  
Hybrid Zone ◽  
Sequence Data ◽  
Strong Support ◽  
Climatic Variables ◽  
Putative Hybrid ◽  
Hybrid Zones ◽  
Intermediate Phenotypes ◽  
Genetic Mechanisms ◽  
Stable Hybrid

Abstract Determining the mechanisms that create and maintain biodiversity is a central question in ecology and evolution. Speciation is the process that creates biodiversity. Speciation is mediated by incompatibilities that lead to reproductive isolation between divergent populations and these incompatibilities can be observed in hybrid zones. Gecko lizards are a speciose clade possessing an impressive diversity of behavioral and morphological traits. In geckos, however, our understanding of the speciation process is negligible. To address this gap, we used genetic sequence data (both mitochondrial and nuclear markers) to revisit a putative hybrid zone between Sphaerodactylus nicholsi and Sphaerodactylus townsendi in Puerto Rico, initially described in 1984. First, we addressed discrepancies in the literature on the validity of both species. Second, we sampled a 10-km-wide transect across the putative hybrid zone and tested explicit predictions about its dynamics using cline models. Third, we investigated potential causes for the hybrid zone using species distribution modeling and simulations; namely, whether unique climatic variables within the hybrid zone might elicit selection for intermediate phenotypes. We find strong support for the species-level status of each species and no evidence of movement, or unique climatic variables near the hybrid zone. We suggest that this narrow hybrid zone is geographically stable and is maintained by a combination of dispersal and selection. Thus, this work has identified an extant model system within geckos that that can be used for future investigations detailing genetic mechanisms of reproductive isolation in an understudied vertebrate group.

scholarly journals Admixture mapping in a hybrid zone reveals loci associated with avian feather coloration

2017 ◽  
Vol 284 (1866) ◽  
pp. 20171106 ◽  
Author(s):  
Alan Brelsford ◽  
David P. L. Toews ◽  
Darren E. Irwin
Keyword(s):  
Hybrid Zone ◽  
Scavenger Receptor ◽  
Genomic Region ◽  
Target Cells ◽  
Hybrid Zones ◽  
Nucleotide Polymorphisms ◽  
Reduced Representation ◽  
Colour Patterns ◽  
Genomic Regions ◽  
Genetic Bases

Identifying the genetic bases for colour patterns has provided important insights into the control and expression of pigmentation and how these characteristics influence fitness. However, much more is known about the genetic bases for traits based on melanin pigments than for traits based on another major class of pigments, carotenoids. Here, we use natural admixture in a hybrid zone between Audubon's and myrtle warblers ( Setophaga coronata auduboni / S. c. coronata ) to identify genomic regions associated with both types of pigmentation. Warblers are known for rapid speciation and dramatic differences in plumage. For each of five plumage coloration traits, we found highly significant associations with multiple single-nucleotide polymorphisms (SNPs) across the genome and these were clustered in discrete regions. Regions near significantly associated SNPs were enriched for genes associated with keratin filaments, fibrils that make up feathers. A carotenoid-based trait that differs between the taxa—throat colour—had more than a dozen genomic regions of association. One cluster of SNPs for this trait overlaps the Scavenger Receptor Class F Member 2 ( SCARF2 ) gene. Other scavenger receptors are presumed to be expressed at target tissues and involved in the selective movement of carotenoids into the target cells, making SCARF2 a plausible new candidate for carotenoid processing. In addition, two melanin-based plumage traits—colours of the eye line and eye spot—show very strong associations with a single genomic region mapping to chromosome 20 in the zebra finch. These findings indicate that only a subset of the genomic regions differentiated between these two warblers are associated with the plumage differences between them and demonstrate the utility of reduced-representation genomic scans in hybrid zones.

scholarly journals Patterns of divergence across the geographic and genomic landscape of a butterfly hybrid zone associated with a climatic gradient

2017 ◽  
Author(s):  
Sean F. Ryan ◽  
Michael C. Fontaine ◽  
J. Mark Scriber ◽  
Michael E. Pfrender ◽  
Shawn T. O’Neil ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Candidate Genes ◽  
Hybrid Zone ◽  
Z Chromosome ◽  
Hybrid Zones ◽  
Seasonal Adaptation ◽  
Developmental Threshold ◽  
Ecological Adaptations ◽  
A Genome ◽  
Genomic Regions

AbstractHybrid zones are a valuable tool for studying the process of speciation and for identifying the genomic regions undergoing divergence and the ecological (extrinsic) and non-ecological (intrinsic) factors involved. Here, we explored the genomic and geographic landscape of divergence in a hybrid zone between Papilio glaucus and Papilio canadensis. Using a genome scan of 28,417 ddRAD SNPs, we identified genomic regions under possible selection and examined their distribution in the context of previously identified candidate genes for ecological adaptations. We showed that differentiation was genome-wide, including multiple candidate genes for ecological adaptations, particularly those involved in seasonal adaptation and host plant detoxification. The Z-chromosome and four autosomes showed a disproportionate amount of differentiation, suggesting genes on these chromosomes play a potential role in reproductive isolation. Cline analyses of significantly differentiated genomic SNPs, and of species diagnostic genetic markers, showed a high degree of geographic coincidence (81%) and concordance (80%) and were associated with the geographic distribution of a climate-mediated developmental threshold (length of the growing season). A relatively large proportion (1.3%) of the outliers for divergent selection were not associated with candidate genes for ecological adaptations and may reflect the presence of previously unrecognized intrinsic barriers between these species. These results suggest that exogenous (climate-mediated) and endogenous (unknown) clines may have become coupled and act together to reinforce reproductive isolation. This approach of assessing divergence across both the genomic and geographic landscape can provide insight about the interplay between the genetic architecture of reproductive isolation and endogenous and exogenous selection.

scholarly journals Absence of heterosis in hybrid crested newts

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5317 ◽  
Author(s):  
Jan W. Arntzen ◽  
Nazan Üzüm ◽  
Maja D. Ajduković ◽  
Ana Ivanović ◽  
Ben Wielstra
Keyword(s):  
Gene Flow ◽  
Hybrid Zone ◽  
Hybrid Sterility ◽  
Introgressive Hybridization ◽  
Growth Curves ◽  
Hybrid Zones ◽  
Population Demography ◽  
Interspecific Gene Flow ◽  
Fertile Hybrids ◽  
Intermediate Situation

Relationships between phylogenetic relatedness, hybrid zone spatial structure, the amount of interspecific gene flow and population demography were investigated, with the newt genusTriturusas a model system. In earlier work, a bimodal hybrid zone of two distantly related species combined low interspecific gene flow with hybrid sterility and heterosis was documented. Apart from that, a suite of unimodal hybrid zones in closely relatedTriturusshowed more or less extensive introgressive hybridization with no evidence for heterosis. We here report on population demography and interspecific gene flow in twoTriturusspecies (T. macedonicusandT. ivanbureschiin Serbia). These are two that are moderately related, engage in a heterogeneous uni-/bimodal hybrid zone and hence represent an intermediate situation. This study used 13 diagnostic nuclear genetic markers in a population at the species contact zone. This showed that all individuals were hybrids, with no parentals detected. Age, size and longevity and the estimated growth curves are not exceeding that of the parental species, so that we conclude the absence of heterosis inT. macedonicus–T. ivanbureschi. Observations across the genus support the hypothesis that fertile hybrids allocate resources to reproduction and infertile hybrids allocate resources to growth. SeveralTriturusspecies hybrid zones not yet studied allow the testing of this hypothesis.

scholarly journals WHERE ARE THE WORMY MICE? A REEXAMINATION OF HYBRID PARASITISM IN THE EUROPEAN HOUSE MOUSE HYBRID ZONE

Evolution ◽  
2012 ◽  
Vol 66 (9) ◽  
pp. 2757-2772 ◽  
Author(s):  
Stuart J. E. Baird ◽  
Alexis Ribas ◽  
Miloš Macholán ◽  
Tomáš Albrecht ◽  
Jaroslav Piálek ◽  
...  
Keyword(s):  
House Mouse ◽  
Hybrid Zone
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