Burness Gary, Moyes Christopher D, Montgomerie Robert
Department of Biology, Trent University, Peterborough, ON, K9J 7B8, Canada.
Comp Biochem Physiol A Mol Integr Physiol. 2005 Jan;140(1):11-7. doi: 10.1016/j.cbpb.2004.09.021.
Male bluegill displays one of two life history tactics. Some males (termed "parentals") delay reproduction until ca. 7 years of age, at which time they build nests and actively courts females. Others mature precociously (sneakers) and obtain fertilizations by cuckolding parental males. In the current study, we studied the relations among sperm motility, ATP levels, and metabolic enzyme activity in parental and sneaker bluegill. In both reproductive tactics, sperm swimming speed and ATP levels declined in parallel over the first 60 s of motility. Although sneaker sperm initially had higher ATP levels than parental sperm, by approximately 30 s postactivation, no differences existed between tactics. No differences were noted between tactics in swimming speed, percent motility, or the activities of key metabolic enzymes, although sperm from parentals had a higher ratio of creatine phosphokinase (CPK) to citrate synthase (CS). In both tactics, with increasing CPK and CS activity, sperm ATP levels increased at 20 s postactivation, suggesting that capacities for phosphocreatine hydrolysis and aerobic metabolism may influence interindividual variation in rates of ATP depletion. Nonetheless, there was no relation between sperm ATP levels and either swimming speed or percent of sperm that were motile. This suggests that interindividual variation in ATP levels may not be the primary determinant of variation in sperm swimming performance in bluegill.
雄性蓝鳃太阳鱼表现出两种生活史策略之一。一些雄性（称为“亲代型”）将繁殖推迟到约7岁，此时它们筑巢并积极求偶雌性。其他雄性早熟（称为“偷情型”），通过欺骗亲代型雄性来获得受精机会。在当前的研究中，我们研究了亲代型和偷情型蓝鳃太阳鱼精子活力、ATP水平和代谢酶活性之间的关系。在两种繁殖策略中，精子游动速度和ATP水平在活动的前60秒内平行下降。虽然偷情型精子最初的ATP水平高于亲代型精子，但在激活后约30秒时，两种策略之间不存在差异。在游动速度、活力百分比或关键代谢酶的活性方面，两种策略之间没有差异，尽管亲代型精子的肌酸磷酸激酶（CPK）与柠檬酸合酶（CS）的比率更高。在两种策略中，随着CPK和CS活性的增加，精子ATP水平在激活后20秒时升高，这表明磷酸肌酸水解能力和有氧代谢可能影响个体间ATP消耗速率的差异。尽管如此，精子ATP水平与游动速度或有活力精子的百分比之间没有关系。这表明ATP水平的个体间差异可能不是蓝鳃太阳鱼精子游动性能差异的主要决定因素。
