Female mediation of competitive fertilization success in Drosophila melanogaster

Stefan Lüpold, Scott S Pitnick, Kirstin S. Berben, Cecilia S. Blengini, John M. Belote, Mollie K. Manier

Research output: Contribution to journalArticle

58 Scopus citations

Abstract

How females store and use sperm after remating can generate postcopulatory sexual selection on male ejaculate traits. Variation in ejaculate performance traits generally is thought to be intrinsic to males but is likely to interact with the environment in which sperm compete (e.g., the female reproductive tract). Our understanding of female contributions to competitive fertilization success is limited, however, in part because of the challenges involved in observing events within the reproductive tract of internally fertilizing species while discriminating among sperm from competing males. Here, we used females from crosses among isogenic lines of Drosophila melanogaster, each mated to two genetically standardized males (the first with green- and the second with red-tagged sperm heads) to demonstrate heritable variation in female remating interval, progeny production rate, sperm-storage organ morphology, and a number of sperm performance, storage, and handling traits. We then used multivariate analyses to examine relationships between this female-mediated variation and competitive paternity. In particular, the timing of female ejection of excess second-male and displaced first-male sperm was genetically variable and, by terminating the process of sperm displacement, significantly influenced the relative numbers of sperm from each male competing for fertilization, and consequently biased paternity. Our results demonstrate that females do not simply provide a static arena for sperm competition but rather play an active and pivotal role in postcopulatory processes. Resolving the adaptive significance of genetic variation in female-mediated mechanisms of sperm handling is critical for understanding sexual selection, sexual conflict, and the coevolution of male and female reproductive traits.

Original languageEnglish (US)
Pages (from-to)10693-10698
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume110
Issue number26
DOIs
StatePublished - Jun 25 2013

    Fingerprint

Keywords

  • Cryptic female choice
  • Heritability
  • Sperm ejection

ASJC Scopus subject areas

  • General

Cite this