多细胞生物的生殖细胞能实现某种形式的“不朽”：生殖细胞（卵子或精子）能够生成它们后代的体细胞，这些体细胞在经过一定的生长和代谢周期之后会死亡；但它们也能生成可以传到下一代的生殖细胞。
对线虫的一系列寿命延长的突变体所做的一项研究显示，仅仅普通体细胞，就可以通过激发正常情况下只见于“不朽”的生殖细胞中的基因表达程序来使寿命延长。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature 459, 1079-1084 (25 June 2009) | doi:10.1038/nature08106
A soma-to-germline transformation in long-lived Caenorhabditis elegans mutants
Sean P. Curran1,2, Xiaoyun Wu1,2, Christian G. Riedel1,2 & Gary Ruvkun1,2
1 Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
2 Department of Genetics, Harvard Medical School, Boston, Massachusetts 02114, USA
Unlike the soma, which ages during the lifespan of multicellular organisms, the germ line traces an essentially immortal lineage. Genomic instability in somatic cells increases with age, and this decline in somatic maintenance might be regulated to facilitate resource reallocation towards reproduction at the expense of cellular senescence. Here we show that Caenorhabditis elegans mutants with increased longevity exhibit a soma-to-germline transformation of gene expression programs normally limited to the germ line. Decreased insulin-like signalling causes the somatic misexpression of the germline-limited pie-1 and pgl family of genes in intestinal and ectodermal tissues. The forkhead boxO1A (FOXO) transcription factor DAF-16, the major transcriptional effector of insulin-like signalling, regulates pie-1 expression by directly binding to the pie-1 promoter. The somatic tissues of insulin-like mutants are more germline-like and protected from genotoxic stress. Gene inactivation of components of the cytosolic chaperonin complex that induce increased longevity also causes somatic misexpression of PGL-1. These results indicate that the acquisition of germline characteristics by the somatic cells of C. elegans mutants with increased longevity contributes to their increased health and survival.
