疯狂的交配导致雄性剑纹带蛇（Thamnophissirtalis parietalis）老化更快，死亡更早。比起雌将维持身体优先于短期生殖的成功的雌性，它们的身体维护要差一些。
来源 悉尼大学
编译 紫苏
在北美地区的剑纹带蛇种群中：雄性每年进行 2-4 周的代价昂贵的交配，在这段时间它们不进食，与成千上万的其他雄性竞争。雌性仅在“狂欢地”停留一天，雄性则可能停留长达21天。
这篇论文发表在 Royal Society journal Proceedings B (论文信息见文末）。
这些蛇在他们的公共巢穴冬眠了八个月，在春天大批醒来，他们聚集在一起，雄性们为着雌性的交配权展开激烈的竞争。
研究人员测定了两个性别的蛇的端粒长度（衰老的生物标志物）。他们发现雄性不能保持较好的身体状态，老化速度快于女性。这可能是因为雄性选择将能力花费在交配上，而没有用于防止和修复与衰老相关的 DNA 和细胞损伤。相比之下，女性优先维持身体状况，并可以更好地修复细胞损伤，让她们有更长的生命和未来的繁殖机会。
悉尼大学的作者 Christopher R Friesen 博士解释说，这些蛇每年只有四个月用于觅食和繁殖，利用这么短时间完成繁殖，它们可算是相当成功。
“虽然我们相信所有的雌性每年都会交配，但他们仅在交配地停留一个小时内1到3天。而雄性要长得多，少则7天，长的可达21天，这似乎导致雄性老化速度更快。“弗里森博士说。
“女性每隔一年繁殖一次，繁殖成功要依赖它们的脂肪/能量储备。我们以前的研究表明，女性真正完成受精之前，可以将精子存储长达15个月或更长时间！”
加拿大马尼托巴省的剑纹带蛇种群。（Christopher R Friesen）
除了优先保护自己的身体以外，在加拿大马尼托巴省研究的雌性剑纹带蛇不会浪费能量照顾他们的后代，与大多数的蛇类是一致的。
原文链接：http://sydney.edu.au/news-opinion/news/2017/04/05/sex-obsession-a-killer-for-male-snakes--research-footage-shows.html
相关论文信息
题目 Age-related sex differences in body condition and telomere dynamics of red-sided garter snakes
作者 Nicky Rollings, Emily J. Uhrig, Randolph W. Krohmer, Heather L. Waye, Robert T. Mason, Mats Olsson, Camilla M. Whittington, Christopher R. Friesen
发表时间 5 April 2017
DOI 10.1098/rspb.2016.2146
摘要 Life-history strategies vary dramatically between the sexes, which may drive divergence in sex-specific senescence and mortality rates. Telomeres are tandem nucleotide repeats that protect the ends of chromosomes from erosion during cell division. Telomeres have been implicated in senescence and mortality because they tend to shorten with stress, growth and age. We investigated age-specific telomere length in female and male red-sided garter snakes, Thamnophis sirtalis parietalis. We hypothesized that age-specific telomere length would differ between males and females given their divergent reproductive strategies. Male garter snakes emerge from hibernation with high levels of corticosterone, which facilitates energy mobilization to fuel mate-searching, courtship and mating behaviours during a two to four week aphagous breeding period at the den site. Conversely, females remain at the dens for only about 4 days and seem to invest more energy in growth and cellular maintenance, as they usually reproduce biennially. As male investment in reproduction involves a yearly bout of physiologically stressful activities, while females prioritize self-maintenance, we predicted male snakes would experience more age-specific telomere loss than females. We investigated this prediction using skeletochronology to determine the ages of individuals and qPCR to determine telomere length in a cross-sectional study. For both sexes, telomere length was positively related to body condition. Telomere length decreased with age in male garter snakes, but remained stable in female snakes. There was no correlation between telomere length and growth in either sex, suggesting that our results are a consequence of divergent selection on life histories of males and females. Different selection on the sexes may be the physiological consequence of the sexual dimorphism and mating system dynamics displayed by this species.
摘要 http://rspb.royalsocietypublishing.org/content/284/1852/20162146
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