A1 Journal article (refereed)
Postmating–prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition (2016)

Ala-Honkola, O., Ritchie, M. G., & Veltsos, P. (2016). Postmating–prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm competition. Ecology and Evolution, 6(6), 1679-1691. https://doi.org/10.1002/ece3.1995

JYU authors or editors

Publication details

All authors or editors: Ala-Honkola, Outi; Ritchie, Michael G.; Veltsos, Paris

Journal or series: Ecology and Evolution

ISSN: 2045-7758

eISSN: 2045-7758

Publication year: 2016

Volume: 6

Issue number: 6

Pages range: 1679-1691

Publisher: John Wiley & Sons Ltd.

Publication country: United Kingdom

Publication language: English

DOI: https://doi.org/10.1002/ece3.1995

Research data link: http://dx.doi.org/10.5061/dryad.085vq

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/49217

Abstract

Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early‐stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the same populations to test whether competitive effects between ejaculates influence this PMPZ isolation. We measured premating isolation in no‐choice tests, female fecundity, fertility and egg‐to‐adult viability after single and double matings as well as second‐male paternity success (P2). Surprisingly, we found no PMPZ reproductive isolation between the two populations under a competitive setting, indicating no difficulty of sperm from Vancouver males to fertilize Colorado eggs after double matings. While there were subtle differences in how P2 changed over time, suggesting that Vancouver males’ sperm are somewhat less competitive in a first‐male role within Colorado females, these effects did not translate into differences in overall P2. Fertilisation success can thus differ dramatically between competitive and noncompetitive conditions, perhaps because the males that mate second produce higher quality ejaculates in response to sperm competition. We suggest that unlike in more divergent species comparisons, where sperm competition typically increases reproductive isolation, ejaculate tailoring can reduce the potential for PMPZ isolation when recently diverged populations interbreed.

Keywords: speciation

Free keywords: ejaculate tailoring; ejaculate-ejaculate interaction; postcopulatory sexual selection; reproductive isolation

Contributing organizations

Ministry reporting: Yes

Reporting Year: 2016

JUFO rating: 1