Hemmings Nicola, Birkhead Tim
Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S102TN, UK
Department of Animal and Plant Sciences, University of Sheffield, Alfred Denny Building, Western Bank, Sheffield S102TN, UK.
Proc Biol Sci. 2017 Aug 16;284(1860). doi: 10.1098/rspb.2017.1032.
When females mate promiscuously, female sperm storage provides scope to bias the fertilization success towards particular males via the non-random acceptance and utilization of sperm. The difficulties observing post-copulatory processes within the female reproductive tract mean that the mechanisms underlying cryptic female choice remain poorly understood. Here, we use zebra finches , selected for divergent sperm lengths, combined with a novel technique for isolating and extracting sperm from avian sperm storage tubules (SSTs), to test the hypothesis that sperm from separate ejaculates are stored differentially by female birds. We show that sperm from different inseminations enter different SSTs in the female reproductive tract, resulting in almost complete segregation of the sperm of competing males. We propose that non-random acceptance of sperm into SSTs, reflected in this case by sperm phenotype, provides a mechanism by which long sperm enjoy enhanced fertilization success in zebra finches.
当雌性进行滥交时，雌性精子储存为通过对精子的非随机接受和利用来使特定雄性的受精成功率产生偏差提供了空间。在雌性生殖道内观察交配后过程存在困难，这意味着对隐性雌性选择背后的机制仍知之甚少。在这里，我们使用经过选择具有不同精子长度的斑胸草雀，并结合一种从鸟类精子储存小管（SSTs）中分离和提取精子的新技术，来检验雌性鸟类对来自不同射精的精子进行差异储存的假设。我们发现，来自不同授精的精子进入雌性生殖道内不同的SSTs，导致竞争雄性的精子几乎完全分离。我们提出，精子进入SSTs时的非随机接受（在这种情况下由精子表型反映）提供了一种机制，通过该机制长精子在斑胸草雀中享有更高的受精成功率。
