Department of Biology, Syracuse University, Syracuse, NY 13244-1270, USA.
Science. 2010 Apr 16;328(5976):354-7. doi: 10.1126/science.1187096. Epub 2010 Mar 18.
Our understanding of postcopulatory sexual selection has been constrained by an inability to discriminate competing sperm of different males, coupled with challenges of directly observing live sperm inside the female reproductive tract. Real-time and spatiotemporal analyses of sperm movement, storage, and use within female Drosophila melanogaster inseminated by two transgenic males with, respectively, green and red sperm heads allowed us to unambiguously discriminate among hypothesized mechanisms underlying sperm precedence, including physical displacement and incapacitation of "resident" sperm by second males, female ejection of sperm, and biased use of competing sperm for fertilization. We find that competitive male fertilization success derives from a multivariate process involving ejaculate-female and ejaculate-ejaculate interactions, as well as complex sperm behavior in vivo.
我们对交配后性选择的理解受到了限制，无法区分不同雄性的竞争精子，并且直接观察雌性生殖道内的活精子也具有挑战性。通过对分别带有绿色和红色精子头的两个转基因雄蝇授精的雌性黑腹果蝇中的精子运动、储存和使用进行实时和时空分析，我们能够明确区分假设的精子优先机制，包括物理置换和第二位雄蝇对“居留”精子的失能、雌性对精子的排出以及对竞争精子用于受精的偏向使用。我们发现，竞争雄性的受精成功率源自涉及精液-雌性和精液-精液相互作用以及体内复杂精子行为的多元过程。
