ABSTRACT

Long intergenic non-coding RNAs (lincRNAs) are transcripts longer than 200 nucleotides that are transcribed from non-coding loci yet undergo biosynthesis similar to coding mRNAs. The disproportional number of lincRNAs expressed in testes suggests that lincRNAs are important during gametogenesis, but experimental evidence has implicated very few lincRNAs in this process. We took advantage of the relatively limited number of lincRNAs in the genome of the nematode Caenorhabditis elegans to systematically analyse the functions of lincRNAs during meiosis. We deleted six lincRNA genes that are highly and dynamically expressed in the C. elegans gonad and tested the effects on central meiotic processes. Surprisingly, whereas the lincRNA deletions did not strongly impact fertility, germline apoptosis, crossovers, or synapsis, linc-4 was required for somatic growth. Slower growth was observed in linc-4-deletion mutants and in worms depleted of linc-4 using RNAi, indicating that linc-4 transcripts are required for this post-embryonic process. Unexpectedly, analysis of worms depleted of linc-4 in soma versus germline showed that the somatic role stems from linc-4 expression in germline cells. This unique feature suggests that some lincRNAs, like some small non-coding RNAs, are required for germ-soma interactions.

摘要

长基因间非编码 RNA (lincRNA) 是长度超过 200 个核苷酸的转录本，从非编码基因座转录而来，但经过类似于编码 mRNA 的生物合成。在睾丸中表达的 lincRNA 数量不成比例表明 lincRNA 在配子发生过程中很重要，但实验证据表明，在此过程中很少有 lincRNA。我们利用线虫秀丽隐杆线虫基因组中相对有限数量的 lincRNA来系统地分析 lincRNA 在减数分裂过程中的功能。我们删除了 6 个在秀丽隐杆线虫中高度动态表达的 lincRNA 基因性腺并测试了对中央减数分裂过程的影响。令人惊讶的是，虽然 lincRNA 缺失并未强烈影响生育力、种系细胞凋亡、交叉或突触，但体细胞生长需要linc-4。中观察到生长较慢LINC-4 -deletion突变体和在耗尽的蠕虫LINC-4使用RNAi，表明LINC-4转录所需要的这种后胚胎的过程。出乎意料的是，对体细胞与种系中linc-4耗尽的蠕虫的分析表明，体细胞的作用源于linc-4在种系细胞中的表达。这一独特的特征表明，胚-体相互作用需要一些 lincRNA，如一些小的非编码 RNA。