Distinct telomere differences within a reproductively bimodal common lizard population.
Distinct telomere differences within a reproductively bimodal common lizard population.
复制标题
生殖双峰蜥蜴种群内明显的端粒差异。
DOI：
10.1111/1365-2435.13408
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发表时间：
2019
影响因子：
5.2
通讯作者：
McLennan D
中科院分区：
文献类型：
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作者：
McLennan D
生殖模式的不同策略，无论是卵生（产卵）还是胎生（活产），都将与一系列其他生活史差异相关，这些差异预计会影响衰老和寿命的模式。由于进化和生态的差异，通常很难比较不同繁殖模式的效果。然而，非常罕见的生殖双峰模式，即同一物种内存在不同的模式，为可靠和受控的比较提供了机会。一个可能与生命史、衰老和寿命有关的感兴趣的特征是端粒的长度，端粒在染色体末端形成保护帽，通常被认为是细胞健康的良好指标。这些端粒的缩短与压力条件有关;因此，不同的生殖成本可能会影响端粒损失的模式。这一点很重要，因为许多研究已经将较短的端粒长度与生存率降低联系起来。我们的研究集中在一个种群中，卵生和胎生个体在同一栖息地共存，偶尔会杂交形成混合个体。虽然胎生为后代带来了许多优势，但它也可能为母亲带来巨大的成本，例如需要更多的能量。因此，我们预测，胎生的母亲将有相对较短的端粒比卵生的母亲，与混合的母亲有中间的端粒长度。端粒长度被认为是一个可遗传的组成部分;因此，我们也假设后代会遵循与母亲相同的模式。与我们的预测相反，胎生的母亲和后代有最长的端粒，而卵生的母亲和后代有最短的端粒。不同的端粒长度可能是由于生殖模式之间的生活史差异而进化的，例如由于胎生个体在生殖时可能经历的增长率增加而达到相似的大小。
Different strategies of reproductive mode, either oviparity (egg‐laying) or viviparity (live‐bearing), will be associated with a range of other life‐history differences that are expected to affect patterns of ageing and longevity. It is usually difficult to compare the effects of alternative reproductive modes because of evolutionary and ecological divergence. However, the very rare exemplars of reproductive bimodality, in which different modes exist within a single species, offer an opportunity for robust and controlled comparisons.One trait of interest that could be associated with life history, ageing and longevity is the length of the telomeres, which form protective caps at the chromosome ends and are generally considered a good indicator of cellular health. The shortening of these telomeres has been linked to stressful conditions; therefore, it is possible that differing reproductive costs will influence patterns of telomere loss. This is important because a number of studies have linked a shorter telomere length to reduced survival.Here, we have studied maternal and offspring telomere dynamics in the common lizard (Zootoca vivipara). Our study has focused on a population where oviparous and viviparous individuals co‐occur in the same habitat and occasionally interbreed to form admixed individuals.While viviparity confers many advantages for offspring, it might also incur substantial costs for the mother, for example require more energy. Therefore, we predicted that viviparous mothers would have relatively shorter telomeres than oviparous mothers, with admixed mothers having intermediate telomere lengths. There is thought to be a heritable component to telomere length; therefore, we also hypothesized that offspring would follow the same pattern as the mothers.Contrary to our predictions, the viviparous mothers and offspring had the longest telomeres, and the oviparous mothers and offspring had the shortest telomeres. The differing telomere lengths may have evolved as an effect of the life‐history divergence between the reproductive modes, for example due to the increased growth rate that viviparous individuals may undergo to reach a similar size at reproduction.A free Plain Language Summary can be found within the Supporting Information of this article.