Data from: Curvilinear telomere length dynamics in a squamate reptile

The lack of consensus concerning the impact of telomere length (TL) dynamics on survival emphasize the need for additional studies to evaluate the effect of TL on key life history processes. Using both cross-sectional and longitudinal data, we therefore explored age-specific TL dynamics in a squamate reptile; the frillneck lizard (Chlamydosaurus kingii). Our cross sectional analyses revealed that young lizards had short TL, TL increased in medium aged lizards but TL decreased in older age cohorts, revealing a curvilinear relationship between TL and frillneck lizard age. Neither our cross-sectional nor our longitudinal analyses revealed any association between TL dynamics and lizard survival. We observed a significant positive relationship between TL and telomerase expression (TE), suggesting that TE is a significant determinant of frillneck lizard TL dynamics. Importantly, our longitudinal analyses revealed a positive relationship between initial TL and telomere attrition rate within individual lizards i.e. lizards with short initial telomeres were subjected to reduced telomere attrition rates compared to lizards with long initial TL. Our results strongly suggest that TL and TE dynamics in frillneck lizards is not associated with lizard survival but rather reflect an adaptation to maintain TL above a critical minimum length in order to sustain cellular homeostasis.

目前学界关于端粒长度（telomere length, TL）动态变化对生物生存的影响尚未达成共识，这凸显了开展更多研究以评估TL对核心生命史过程作用的必要性。为此，我们结合横断面数据与纵向数据，对有鳞目爬行动物褶伞蜥（Chlamydosaurus kingii）的年龄特异性TL动态变化展开了探究。横断面分析结果显示，幼年褶伞蜥的端粒长度较短，中年个体的端粒长度有所升高，而老年个体的端粒长度则出现下降，表明TL与褶伞蜥年龄之间存在曲线型关联。无论是横断面分析还是纵向分析，均未发现TL动态变化与褶伞蜥生存存在任何关联。我们观察到TL与端粒酶表达（telomerase expression, TE）之间存在显著正相关关系，提示TE是调控褶伞蜥TL动态变化的重要决定因素。尤为关键的是，纵向分析结果显示，个体褶伞蜥的初始TL与端粒损耗速率呈正相关关系——即初始端粒长度较短的个体，其端粒损耗速率相较于初始TL较长的个体更低。本研究结果强烈表明，褶伞蜥的TL与TE动态变化与个体生存并无关联，反而反映出一种适应性策略：通过维持TL高于临界最小长度，以维持细胞稳态。