Lunghi Enrico, Bilandžija Helena
Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
Division of Molecular Biology, Ruder Bošković Institute, Zagreb, Croatia.
PeerJ. 2024 Feb 28;12:e16957. doi: 10.7717/peerj.16957. eCollection 2024.
Telomeres are non-coding DNA repeats at the chromosome ends and their shortening is considered one of the major causes of aging. However, they also serve as a biomarker of environmental exposures and their length and attrition is affected by various stressors. In this study, we examined the average telomere length in , a species that has both surface-dwelling and cave-adapted populations. The cave morph descended from surface ancestors and adapted to a markedly different environment characterized by specific biotic and abiotic stressors, many of which are known to affect telomere length. Our objective was to explore whether telomere length differs between the two morphs and whether it serves as a biological marker of aging or correlates with the diverse environments the morphs are exposed to.
We compared telomere length and shortening between laboratory-reared Pachón cavefish and Rio Choy surface fish of across different tissues and ages.
surface fish exhibited longer average telomere length compared to cavefish. In addition, we did not observe telomere attrition in either cave or surface form as a result of aging in adults up to 9 years old, suggesting that efficient mechanisms prevent telomere-mediated senescence in laboratory stocks of this species, at least within this time frame. Our results suggest that telomere length in may be considered a biomarker of environmental exposures. Cavefish may have evolved shorter and energetically less costly telomeres due to the absence of potential stressors known to affect surface species, such as predator pressure and ultra-violet radiation. This study provides the first insights into telomere dynamics in morphs and suggests that shorter telomeres may have evolved as an adaptation to caves.
端粒是染色体末端的非编码DNA重复序列，其缩短被认为是衰老的主要原因之一。然而，它们也作为环境暴露的生物标志物，其长度和损耗受各种应激源的影响。在本研究中，我们检测了一种既有表层栖息种群又有洞穴适应种群的物种的平均端粒长度。洞穴形态起源于表层祖先，适应了一个明显不同的环境，其特征是特定的生物和非生物应激源，其中许多已知会影响端粒长度。我们的目标是探究两种形态之间的端粒长度是否不同，以及它是否作为衰老的生物标志物或与形态所暴露的不同环境相关。
我们比较了实验室饲养的帕琼洞穴鱼和里奥乔伊表层鱼在不同组织和年龄阶段的端粒长度和缩短情况。
与洞穴鱼相比，表层鱼的平均端粒长度更长。此外，在9岁以下的成年鱼中，我们未观察到洞穴形态或表层形态的端粒因衰老而损耗，这表明至少在这个时间范围内，该物种的实验室种群中有有效的机制防止端粒介导的衰老。我们的结果表明，该物种的端粒长度可能被视为环境暴露的生物标志物。由于不存在已知会影响表层物种的潜在应激源，如捕食压力和紫外线辐射，洞穴鱼可能进化出了更短且能量消耗更低的端粒。这项研究首次深入了解了该物种两种形态的端粒动态，并表明较短的端粒可能是对洞穴环境的一种适应进化而来。
