PDF(Pubmed)
Abstract：
The animal germline lineage needs to be maintained along generations. However, some Caenorhabditis elegans wild isolates display a mortal germline phenotype, leading to sterility after several generations at 25°C. Using a genome-wide association approach, we detect a significant peak on chromosome III around 5 Mb, confirmed by introgressions. Thus, a seemingly deleterious genotype is maintained at intermediate frequency in the species. Environmental rescue is a likely explanation, and indeed associated bacteria and microsporidia suppress the phenotype of wild isolates as well as mutants in small RNA inheritance (nrde-2) and histone modifications (set-2). Escherichia coli strains of the K-12 lineage suppress the phenotype compared to B strains. By shifting a wild strain from E. coli K-12 to E. coli B, we find that memory of the suppressing condition is maintained over several generations. Thus, the mortal germline phenotype of wild C. elegans is in part revealed by laboratory conditions and may represent variation in epigenetic inheritance and environmental interactions. This study also points to the importance of non-genetic memory in the face of environmental variation.
摘要：
动物种系谱系需要世代相传。然而,一些秀丽隐杆线虫野生分离株显示出致命的种系表型，在25°C下几代后导致不育。使用全基因组关联方法，我们在染色体III的5Mb附近检测到一个显著的峰，通过渗入证实。因此，一个看似有害的基因型是维持在中间频率的物种。环境救援是一个可能的解释，实际上，相关的细菌和微孢子虫抑制了野生分离株的表型以及小RNA遗传（nrde-2）和组蛋白修饰（set-2）中的突变体。与B菌株相比，K-12谱系的大肠杆菌菌株抑制了表型。通过将野生菌株从大肠杆菌K-12转移到大肠杆菌B，我们发现抑制状况的记忆在几代人中得以维持。因此，野生C.elegans的致命种系表型部分由实验室条件揭示，可能代表表观遗传和环境相互作用的变异。这项研究还指出了非遗传记忆在面对环境变异时的重要性。
