Briskie J V, Montgomerie R
Department of Biology, Queen's University, Kingston, Ontario, Canada.
Proc Biol Sci. 1992 Feb 22;247(1319):89-95. doi: 10.1098/rspb.1992.0013.
In a sample of 20 species of North American passerine birds we found no relation between sperm size and mating system like that previously reported in mammals (Gomendio & Roldan (Proc. R. Soc. Lond. B 243, 181 (1991)). Instead, we found a positive correlation between sperm length and the length of female sperm storage tubules (SSTS) and a negative correlation between sperm length and the number of SSTS. Both of these correlations suggest that the more than fivefold variation in sperm size we found among species can be explained by sperm competition for access to storage sites (SSTS) in females. As longer sperm appear to be able to swim faster, selection should favour long sperm when SSTS are in short supply; sperm long enough to fill an SST might also prevent access to SSTS by the sperm of other males. Conversely, selection should favour shorter sperm when there is an advantage to sperm layering within an SST promoting a last-male mating advantage. Although we conclude that sperm competition influences sperm size in birds, little is known about the interactions between sperm and SSTS. It seems clear, however, that detailed study of this interaction will provide a new dimension to the study of avian mating systems.
在一个包含20种北美雀形目鸟类的样本中，我们未发现精子大小与交配系统之间存在先前在哺乳动物中所报道的那种关系（戈门迪奥和罗尔丹（《伦敦皇家学会学报B》243, 181 (1991)））。相反，我们发现精子长度与雌性精子储存管（SSTS）的长度呈正相关，与SSTS的数量呈负相关。这两种相关性都表明，我们在物种间发现的精子大小超过五倍的差异可以通过精子为获取雌性体内储存位点（SSTS）的竞争来解释。由于较长的精子似乎能够游得更快，当SSTS供应短缺时，选择应有利于长精子；足够长以填满一个SST的精子也可能会阻止其他雄性的精子进入SSTS。相反，当在一个SST内精子分层具有促进最后交配雄性的优势时，选择应有利于较短的精子。尽管我们得出精子竞争会影响鸟类精子大小的结论，但对于精子与SSTS之间的相互作用却知之甚少。然而，很明显，对这种相互作用的详细研究将为鸟类交配系统的研究提供一个新的维度。
