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- Mugal, Carina, et al.
(författare)
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Tissue-specific patterns of regulatory changes underlying gene expression differences among Ficedula flycatchers and their naturally occurring F1 hybrids
- 2020
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 30:12, s. 1727-1739
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Tidskriftsartikel (refereegranskat)abstract
- Changes in interacting cis- and trans-regulatory elements are important candidates for Dobzhansky-Muller hybrid incompatibilities and may contribute to hybrid dysfunction by giving rise to misexpression in hybrids. To gain insight into the molecular mechanisms and determinants of gene expression evolution in natural populations, we analyzed the transcriptome from multiple tissues of two recently diverged Ficedula flycatcher species and their naturally occurring F1 hybrids. Differential gene expression analysis revealed that the extent of differentiation between species and the set of differentially expressed genes varied across tissues. Common to all tissues, a higher proportion of Z-linked genes than autosomal genes showed differential expression, providing evidence for a fast-Z effect. We further found clear signatures of hybrid misexpression in brain, heart, kidney, and liver. However, while testis showed the highest divergence of gene expression among tissues, it showed no clear signature of misexpression in F1 hybrids, even though these hybrids were found to be sterile. It is therefore unlikely that incompatibilities between cis-trans regulatory changes explain the observed sterility. Instead, we found evidence that cis-regulatory changes play a significant role in the evolution of gene expression in testis, which illustrates the tissue-specific nature of cis-regulatory evolution bypassing constraints associated with pleiotropic effects of genes.
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- Ålund, Murielle, et al.
(författare)
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Reproductive -omics of a wild avian speciation model unveils candidate genes for gamete interaction
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The complex nature of interspecific interactions contributing to reproductive isolation means that we still know little about their molecular basis. Male reproductive traits are notorious for their fast evolution at the phenotypic and genotypic level, and divergence in components of the ejaculate can lead to incompatibilities between closely related species. Making use of recent advances of molecular tools and the extensive knowledge on the biology and ecology of young sister species, here the pied (Ficedula hypoleuca) and collared flycatcher (F. albicollis), allows the identification of candidate phenotypes and the underlying genotypes maintaining species boundaries. Pied flycatcher females can avoid costly production of sterile hybrids when mated to collared flycatchers by cryptically favouring conspecific sperm. Here, we describe the testes transcriptome and sperm proteome of both species, confirm the complexity of avian sperm development and functions and identify several candidate genes for interactions between sperm and the female reproductive tract, using multiple independent measures of divergence between the species. We show that divergence at the transcriptional and translational levels can potentially lead to the evolution of reproductive incompatibilities despite low levels of sequence divergence, and suggest that integrating several -omics techniques with knowledge of the biology of naturally hybridizing species will greatly improve our understanding of the molecular basis of speciation in the near future.
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