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Title: Molecular mechanisms of postmating prezygotic reproductive isolation uncovered by transcriptome analysis

Little is known about the physiological responses and genetic mutations associated with reproductive isolation between species, especially for postmating prezygotic isolating barriers. Here, we examine changes in gene expression that accompany the expression of ‘unilateral incompatibility’ (UI)—a postmating prezygotic barrier in which fertilization is prevented by gamete rejection in the reproductive tract [in this case of pollen tubes (male gametophytes)] in one direction of a species cross, but is successful in the reciprocal crossing direction. We use whole‐transcriptome sequencing of multiple developmental stages of male and female tissues in twoSolanumspecies that exhibitUIto: (i) identify transcript differences betweenUI‐competent andUInoncompetent tissues; (ii) characterize transcriptional changes specifically associated with the phenotypic expression ofUI; and (iii) using these comparisons, evaluate the behaviour of a priori candidate loci forUIand identify new candidates for future manipulative work. In addition to describing transcriptome‐wide changes in gene expression that accompany this isolating barrier, we identify at least five strong candidates for involvement in postmating prezygotic incompatibility between species. These include three novel candidates and two candidates that are strongly supported by prior developmental, functional, and quantitative trait locus mapping studies. These latter genes are known molecular players in the intraspecific expression of mate choice via genetic self‐incompatibility, and our study supports prior evidence that these inter‐ and intraspecific postmating prezygotic reproductive behaviours share specific genetic and molecular mechanisms.

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Author(s) / Creator(s):
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Date Published:
Journal Name:
Molecular Ecology
Page Range / eLocation ID:
p. 2592-2608
Medium: X
Sponsoring Org:
National Science Foundation
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