Ryazansky Sergei S, Kotov Alexei A, Kibanov Mikhail V, Akulenko Natalia V, Korbut Alina P, Lavrov Sergei A, Gvozdev Vladimir A, Olenina Ludmila V
Laboratory of Biochemical Genetics of Animals, Institute of Molecular Genetics RAS, 2 Kurchatov Sq., Moscow 123182, Russia.
Laboratory of Biochemical Genetics of Animals, Institute of Molecular Genetics RAS, 2 Kurchatov Sq., Moscow 123182, Russia.
Eur J Cell Biol. 2016 Sep;95(9):311-22. doi: 10.1016/j.ejcb.2016.06.001. Epub 2016 Jun 6.
Germline-specific RNA helicase Spindle-E (Spn-E) is known to be essential for piRNA silencing in Drosophila that takes place mainly in the perinuclear nuage granules. Loss-of-function spn-E mutations lead to tandem Stellate genes derepression in the testes and retrotransposon mobilization in the ovaries. However, Spn-E functions in the piRNA pathway are still obscure. Analysis of total library of short RNAs from the testes of spn-E heterozygous flies revealed the presence of abundant piRNA ping-pong pairs originating from Su(Ste) transcripts. The abundance of these ping-pong pairs were sharply reduced in the library from the testes of spn-E mutants. Thus we found that ping-pong mechanism contributed to Su(Ste) piRNA generation in the testes. The lack of Spn-E caused a significant drop of protein levels of key ping-pong participants, Aubergine (Aub) and AGO3 proteins of PIWI subfamily, in the germline of both males and females, but did not disrupt of their assembly in nuage granules. We found that observed decline of the protein expression was not caused by suppression of aub and ago3 transcription as well as total transcription, indicating possible contribution of Spn-E to post-transcriptional regulation.
种系特异性RNA解旋酶纺锤体-E（Spn-E）已知对果蝇中的piRNA沉默至关重要，这种沉默主要发生在核周的云雾状颗粒中。功能缺失的spn-E突变会导致睾丸中串联的星状基因去抑制以及卵巢中的逆转录转座子动员。然而，Spn-E在piRNA途径中的功能仍然不清楚。对spn-E杂合果蝇睾丸中的短RNA总文库进行分析，发现存在大量源自Su(Ste)转录本的piRNA乒乓对。在spn-E突变体睾丸的文库中，这些乒乓对的丰度急剧降低。因此我们发现乒乓机制有助于睾丸中Su(Ste) piRNA的产生。Spn-E的缺失导致雄性和雌性生殖系中关键乒乓参与者、PIWI亚家族的茄子（Aub）和AGO3蛋白的蛋白质水平显著下降，但并未破坏它们在云雾状颗粒中的组装。我们发现观察到的蛋白质表达下降不是由aub和ago3转录以及总转录的抑制引起的，这表明Spn-E可能对转录后调控有贡献。
