Intraspecific variation in reproductive barriers between two closely related Arabidopsis sister species. (27th November 2022)

• Record Type: Journal Article
• Authors: Perrier, Antoine; Willi, Yvonne
• Is Part Of: Journal of evolutionary biology. Volume 36:Number 1(2023)
• Page Start: 121
• Page End: 130
• Publication Date: 2022-11-27
• Subjects: Arabidopsis -- genetic distance -- reproductive barrier -- speciation -- variation in reproductive isolation; Evolution (Biology) -- Periodicals; Biology -- Periodicals; 576.8
• DOI: 10.1111/jeb.14122
• Languages: English
• ISSNs: 1010-061X

Abstract

Abstract: Reproductive isolation (RI) is a critical component of speciation and varies strongly in timing and strength among different sister taxa, depending on, for example the geography of speciation and divergence time. However, these factors may also produce variation in timing and strength among populations within species. Here we tested for variation in the expression of RI among replicate population pairs between the sister taxa Arabidopsis lyrata subsp. lyrata and A. arenicola . While the former is predominantly outcrossing, the latter is predominantly selfing. We focused on intrinsic prezygotic and postzygotic RI as both species occur largely in allopatry. We assessed RI by performing within‐population crosses and interspecific between‐population crosses, and by raising offspring. RI was generally high between all interspecific population pairs, but it varied in timing and strength depending on population history. Prezygotic isolation was strongest between the closest‐related population pair, while early postzygotic isolation was high for all other population pairs. Furthermore, the timing and strength of RI depended strongly on cross direction. Our study provides empirical support that reproductive barriers between species are highly variable among population pairs and asymmetric within population pairs, and this variation seems to follow patterns typically described across species pairs. Abstract : Reproductive isolation (RI) is a critical component of speciation and varies strongly in timing and strength among different sister taxa, depending on, for example the geography of speciation and divergence time. However, these factors may also produce variation in timing and strength among populations within species. Here we tested for variation in postmating prezygotic and intrinsic postzygotic reproductive barriers among replicate population pairs of the recently diverged allopatric sister taxa Arabidopsis lyrata subsp. lyrata and A. arenicola . We found that RI among interspecific crosses was generally high, but varied strongly depending on population history and cross direction. As we discuss in the paper, this variation also seems to follow patterns typically described on the level of species.