Department of Molecular Genetics, Collaborative Program in Developmental Biology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
Science. 2011 Sep 2;333(6047):1311-4. doi: 10.1126/science.1208178.
RNA can act as a regulator of gene expression with roles in transposon silencing, antiviral defense, and cell fate determination. Here, we show that in Caenorhabditis elegans a maternal transcript of the sex-determining gene fem-1 is required to license expression of a wild-type fem-1 allele in the zygotic germ line. Females homozygous for fem-1 deletions produce heterozygous offspring exhibiting germline feminization, reduced fem-1 activity, and transcript accumulation. Injection of fem-1 RNA incapable of encoding a protein into the maternal germ line rescues this defect in the progeny. The defect in zygotic fem-1 expression is heritable, suggesting that the gene is subject to epigenetic silencing that is prevented by maternal fem-1 transcripts. This mechanism may contribute to protecting the identity and integrity of the germ line.
RNA 可以作为基因表达的调节剂，在转座子沉默、抗病毒防御和细胞命运决定中发挥作用。在这里，我们表明在秀丽隐杆线虫中，性别决定基因 fem-1 的母本转录本需要在合子生殖系中许可野生型 fem-1 等位基因的表达。fem-1 缺失纯合的雌性产生具有生殖系雌性化、fem-1 活性降低和转录物积累的杂合后代。将不能编码蛋白质的 fem-1 RNA 注入母本生殖系中可挽救后代的这种缺陷。合子 fem-1 表达的缺陷是可遗传的，这表明该基因受到表观遗传沉默的影响，而母本 fem-1 转录本可以防止这种沉默。这种机制可能有助于保护生殖系的身份和完整性。
