Age-related sex differences in body condition and telomere dynamics of red-sided garter snakes

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 us...两性间的生活史策略存在显著差异，这可能导致性别特异性衰老速率与死亡率产生分化。端粒（Telomere）是串联式核苷酸重复序列，可在细胞分裂过程中保护染色体末端免受降解。鉴于端粒会随应激、生长及年龄增长而逐渐缩短，其被认为与衰老和死亡率密切相关。本研究针对红边束带蛇（Thamnophis sirtalis parietalis）的雌雄个体开展了年龄特异性端粒长度检测。我们提出假说：鉴于雌雄个体繁殖策略存在显著差异，二者的年龄特异性端粒长度亦会有所不同。雄性红边束带蛇冬眠苏醒后皮质酮水平较高，这可促进能量动员，以支撑其在巢穴区域为期2至4周的绝食繁殖期内的求偶搜寻、求偶展示及交配行为。与之相反，雌性个体仅在巢穴停留约4天，且似乎会将更多能量投入生长与细胞维持，因为它们会……