Freshwater polyps of the genus Hydra do not age. However, temperature stress induces aging and a shift from reproduction by asexual budding to sexual gamete production in a cold-sensitive (CS) strain of H. oligactis. We sequenced the transcriptome of a male CS strain before and after this life history shift and compared changes in gene expression relative to those seen in a cold-resistant (CR) strain that does not undergo a life history shift in response to altered temperature. We found that the switch from non-aging asexual reproduction to aging and sexual reproduction involves upregulation of genes not only involved in gametogenesis but also genes involved in cellular senescence, apoptosis, and DNA repair accompanied by a downregulation of genes involved in stem cell maintenance. These results suggest that aging is a byproduct of sexual reproduction-associated cellular reprogramming and underscore the power of these H. oligactis strains to identify intrinsic mechanisms of aging.

中文翻译：

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Hydra oligactis 的可诱导衰老暗示有性生殖、干细胞丢失和基因组维持是主要途径。

九头蛇属的淡水息肉不会老化。然而，在冷敏感 (CS)寡聚体菌株中，温度压力会导致衰老和从无性萌芽繁殖到有性配子产生的转变。我们对这种生活史转变前后的雄性 CS 菌株的转录组进行了测序，并比较了基因表达的变化与抗寒 (CR) 菌株中所见的变化，该菌株不会因温度变化而发生生活史转变。我们发现从非衰老无性繁殖到衰老和有性繁殖的转变涉及不仅涉及配子发生的基因的上调，还涉及涉及细胞衰老、细胞凋亡和 DNA 修复的基因的上调，伴随着干细胞维持相关基因的下调。这些结果表明衰老是与有性生殖相关的细胞重编程的副产品，并强调了这些寡乳杆菌菌株识别衰老内在机制的能力。