The genomic landscape underlying phenotypic integrity in the face of gene flow in crows

  title={The genomic landscape underlying phenotypic integrity in the face of gene flow in crows},
  author={Jelmer W. Poelstra and Nagarjun Vijay and Christen M. Bossu and Henrik Lantz and Bettina Ryll and Inge M{\"u}ller and Vittorio Baglione and Per Unneberg and Martin Wikelski and Manfred G. Grabherr and Jochen B. W. Wolf},
  pages={1410 - 1414}
Crows of a feather flock together Closely related species with overlapping ranges typically evolve genetic barriers to prevent crossbreeding. Poelstra et al. sequenced genes from two species of central European crows: gray-bodied hooded crows and black carrion crows (see the Perspective by de Knijff). Although most of the genomes shared genes between the two species, one region that affected coat color and color vision differed. The authors suggest that black and gray-coated crows prefer to… 

Epistatic mutations under divergent selection govern phenotypic variation in the crow hybrid zone

This study reveals how few, large-effect loci can govern prezygotic isolation and shield phenotypic divergence from gene flow and shows that variation in hybrid colour phenotypes is explained by recessive epistasis between two pigmentation genes, which are targets of divergent selection.

Cryptic and extensive hybridization between ancient lineages of American crows

It is found that American and Northwestern crows have distinct evolutionary histories, supported by two nuDNA ancestry clusters and two 1.1%-divergent mtDNA clades dating to the late Pleistocene, when glacial advances may have isolated crow populations in separate refugia.

Phylogeography and hybridization of corvid birds in the Palearctic Region

  • A. Kryukov
  • Biology
    Vavilov Journal of Genetics and Breeding
  • 2019
Comparing European and Siberian crow hybrid zones, differences in genome regions bearing genes of melanogenesis supposedly under divergent selection were found and NGS resulted in a clear pattern of diversification of pure forms and hybrids, and showed genomic regions of increased variability, the so-called “speciation islands”.

Genome divergence and diversification within a geographic mosaic of coevolution

These findings suggest that mechanisms related to recent local coevolution between South Hills crossbills and lodgepole pine (e.g. strong resource‐based density dependence limiting gene flow) have been associated with genome divergence in the face of gene flow.

Transcriptomics of colour patterning and coloration shifts in crows

Light is shed on the molecular elements regulating regional pigment production in two genetically near‐identical crow taxa with striking differences in a eumelanin‐based phenotype: black carrion and grey‐coated hooded crows and concludes that colour pattern differences between the taxa likely result from an interaction between divergence in upstream elements of the melanogenesis pathway and genes that provide an underlying prepattern across the body through positional information.

Lack of gene flow: Narrow and dispersed differentiation islands in a triplet of Leptidea butterfly species

Divergence landscapes in Leptidea have been shaped by directional selection and genetic drift rather than stable recombination landscapes and/or introgression, suggesting recurrent directional selection on a specific set of traits in all comparisons.

A novel locus on chromosome 1 underlies the evolution of a melanic plumage polymorphism in a wild songbird

This work investigated how and why phenotypic diversity arose and persists in the Zosterops borbonicus white-eye of Reunion, a colour polymorphic songbird in which all highland populations contain individuals belonging to either a brown or a grey plumage morph, and showed that the dominant ‘grey’ allele spread quickly once it arose from a new mutation.

Species Persistence with Hybridization in Toad-Headed Lizards Driven by Divergent Selection and Low Recombination

Insight is provided into the genomic mechanisms that drive RI and two species persistence in the face of gene flow during the late stage of speciation.

Plumage Genes and Little Else Distinguish the Genomes of Hybridizing Warblers

Positive selection plays a major role in shaping signatures of differentiation across the genomic landscape of two independent Ficedula flycatcher species pairs *

Both shared and lineage-specific FST peaks could partially be explained by selective sweeps, with recurrent selection likely to underlie shared signatures of selection, while indirect evidence supports a role of recombination landscape evolution in driving lineage specific-signatures of selection.



An extensive candidate gene approach to speciation: diversity, divergence and linkage disequilibrium in candidate pigmentation genes across the European crow hybrid zone

The results add to the debate as to the utility of candidate gene approaches in relation to genomic features and the genetic architecture of the phenotypic trait in question, by identifying a comprehensive panel of 95 candidate pigmentation genes for birds.

Genome-wide evidence for speciation with gene flow in Heliconius butterflies

Overall these results show that species divergence can occur in the face of persistent and genome-wide admixture over long periods of time.

Nucleotide divergence vs. gene expression differentiation: comparative transcriptome sequencing in natural isolates from the carrion crow and its hybrid zone with the hooded crow

A clear clustering of expression profiles is found for the pure carrion crow animals and disperse profiles for the animals from the hybrid zone, suggesting that gene expression differences may indeed be a sensitive indicator of initial species divergence.

Genomic islands of divergence are not affected by geography of speciation in sunflowers.

It is found that genetic divergence is lower in sympatric and parapatric comparisons, consistent with a role for gene flow in eroding neutral differences, and the results indicate that the functional architecture of genomes plays a larger role in shaping genomic divergence than does the geography of speciation.

An analysis of population genetic differentiation and genotype–phenotype association across the hybrid zone of carrion and hooded crows using microsatellites and MC1R

A similar degree of genetic differentiation was found between allopatric and edge populations irrespectively of their location in relation to the hybrid zone, which is striking considering that carrion and hooded crows are phenotypically distinct and sometimes recognised as separate species.

The genomic landscape of species divergence in Ficedula flycatchers

This study provides a roadmap to the emerging field of speciation genomics by showing that the genomic landscape of species differentiation is highly heterogeneous with approximately 50 ‘divergence islands’ showing up to 50-fold higher sequence divergence than the genomic background.

Hybridization and speciation

A perspective on the context and evolutionary significance of hybridization during speciation is offered, highlighting issues of current interest and debate and suggesting that the Dobzhansky–Muller model of hybrid incompatibilities requires a broader interpretation.

The genomics of speciation-with-gene-flow.

Butterfly genome reveals promiscuous exchange of mimicry adaptations among species

It is inferred that closely related Heliconius species exchange protective colour-pattern genes promiscuously, implying that hybridization has an important role in adaptive radiation.

Revisiting the Impact of Inversions in Evolution: From Population Genetic Markers to Drivers of Adaptive Shifts and Speciation?

There is a growing appreciation that chromosome inversions affect rates of adaptation, speciation, and the evolution of sex chromosomes, but few genes within inversions responsible for fitness effects or speciation have been identified.