Abstract

Age-related changes in telomere length (TL) in somatic tissues are not limited only to shortening. It is known that many organisms show different TL dynamics. Such species specificity indicates the complexity of the mechanisms involved in the regulation of TL. Owing to their morphological, physiological, and ecological features, Baikal planarians are an interesting model for studying the TL dynamics and the factors influencing it in comparison with species living outside Baikal. In this work, we investigated telomerase activity and age-related changes in TL in three endemic species of planarians from the Dendrocoelidae family. Two species are giant deep-water species (7–12 cm long, Sorocelis hepatizon and Rimacephalus arecepta), and one is a coastal shallow species (1 cm long, Baikalobia guttata). In addition, we investigated the telomere biology in another small Siberian species from the Planariidae family (2 cm in length, Phagocata sibirica), which is not found in Baikal. TL and telomerase activity were determined using real-time PCR and the TRAP method. Three types of age-related TL dynamics were detected with active telomerase: (1) TL shortening at the juvenile stage of development and subsequent maintenance (R. arecepta, Ph. sibirica), (2) gradual TL shortening during ontogeny (S. hepatizon) and (3) cyclic dynamics of TL (B. guttata). Thus, the changes of TL in the studied planarians does not have an obvious connection with body size, habitat depth, phylogenetic relationship and is probably a consequence of species features in the regulation of telomerase activity.

中文翻译：

---

贝加尔湖地方病中端粒长度的年龄动态。

摘要

体细胞组织中端粒长度（TL）的年龄相关变化不仅限于缩短。众所周知，许多生物表现出不同的TL动力学。这样的物种特异性表明了调控TL所涉及机制的复杂性。由于它们的形态，生理和生态特征，与生活在贝加尔湖以外的物种相比，贝加尔湖的平面学家是研究TL动力学及其影响因素的有趣模型。在这项工作中，我们调查了来自Dendrocoelidae家族的三种地方性平面虫的端粒酶活性和TL中与年龄相关的变化。两种是巨型深水物种（长7–12厘米，Sorocelis hepatizon和Rimacephalus arecepta），一种是沿海浅水物种（长1厘米，Baikalobia guttata）。此外，我们调查了另一种来自Planariidae家族（长度为2 cm，Phagocata sibirica）的西伯利亚小物种的端粒生物学，该物种在贝加尔湖中找不到。使用实时PCR和TRAP方法测定TL和端粒酶活性。用活性端粒酶检测三种类型的年龄相关的TL动力学的：（1）在显影和后续维护（的幼年期TL缩短R. arecepta，。博士西伯利亚），（2）个体发育逐渐缩短TL（S. hepatizon）和（3）TL（B.guttata）。因此，研究的涡虫中TL的变化与体型，生境深度，系统发育关系没有明显联系，可能是端粒酶活性调节中物种特征的结果。