Cryptic female choice favours sperm from major histocompatibility complex-dissimilar males
2013 (English)In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, no 1769, 20131296- p.Article in journal (Refereed) Published
Cryptic female choice may enable polyandrous females to avoid inbreeding or bias offspring variability at key loci after mating. However, the role of these genetic benefits in cryptic female choice remains poorly understood. Female red junglefowl, Gallus gallus, bias sperm use in favour of unrelated males. Here, we experimentally investigate whether this bias is driven by relatedness per se, or by similarity at the major histocompatibility complex (MHC), genes central to vertebrate acquired immunity, where polymorphism is critical to an individual's ability to combat pathogens. Through experimentally controlled natural matings, we confirm that selection against related males' sperm occurs within the female reproductive tract but demonstrate that this is more accurately predicted by MHC similarity: controlling for relatedness per se, more sperm reached the eggs when partners were MHC-dissimilar. Importantly, this effect appeared largely owing to similarity at a single MHC locus (class I minor). Further, the effect of MHC similarity was lost following artificial insemination, suggesting that male phenotypic cues might be required for females to select sperm differentially. These results indicate that postmating mechanisms that reduce inbreeding may do so as a consequence of more specific strategies of cryptic female choice promoting MHC diversity in offspring.
Place, publisher, year, edition, pages
2013. Vol. 280, no 1769, 20131296- p.
genetic relatedness, major histocompatibility complex, postcopulatory sexual selection, sperm choice
Ecology Environmental Sciences Evolutionary Biology
IdentifiersURN: urn:nbn:se:su:diva-101256DOI: 10.1098/rspb.2013.1296ISI: 000330322000002OAI: oai:DiVA.org:su-101256DiVA: diva2:700118
FunderKnut and Alice Wallenberg Foundation