Searching for non-transposable targets of planarian nuclear PIWI in pluripotent stem cells and differentiated cells
Searching for non-transposable targets of planarian nuclear PIWI in pluripotent stem cells and differentiated cells
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DOI：
10.1111/dgd.12536
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发表时间：
2018-06-01
影响因子：
2.5
通讯作者：
Shibata, Norito
中科院分区：
文献类型：
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作者：
Kashima, Makoto;Agata, Kiyokazu;Shibata, Norito
核 PIWI 与其引导 RNA (piRNA) 一起表观遗传地沉默多种基因，包括许多生物体中的转座子。在真涡虫中，核 piwi 家族基因 DjpiwiB 在成体多能干细胞（成体 PSC、新生细胞）中特异性转录，但不在分化细胞中转录。然而，该蛋白质在新生细胞及其后代分化细胞的细胞核中积累。有趣的是，PIWI(DjPiwiB)-piRNA 复合物对于在新生细胞分化开始时抑制转座基因是不可或缺的。在这里，我们在对照动物和 DjpiwiB(RNAi) 动物之间进行了比较转录组分析，以确定 DjPiwiB-piRNA 复合物的非转座靶基因。通过生物信息学分析和 RNAi，我们证明 DjPiwiB-piRNA 复合物是 Djmcm2 和 Djhistone h4 在新生细胞中正确表达所必需的，并且 DjPiwiB-piRNA 复合物在新生细胞分化过程中调节 Djcalu 的瞬时表达。因此，DjPiwiB-piRNA 复合物在新生细胞自我更新和分化过程中调节正确的表达模式。
Nuclear PIWIs together with their guide RNAs (piRNAs) epigenetically silence various genes including transposons in many organisms. In planarians, the nuclear piwi family gene, DjpiwiB is specifically transcribed in adult pluripotent stem cells (adult PSC, neoblast), but not in differentiated cells. However, the protein accumulates in the nuclei of both neoblasts and their descendant differentiated cells. Interestingly, PIWI(DjPiwiB)-piRNA complexes are indispensable for the repression of transposable genes at the onset of differentiation from neoblasts. Here, we conducted a comparative transcriptome analysis between control and DjpiwiB(RNAi) animals to identify non-transposable target genes of the DjPiwiB-piRNA complexes. Using bioinformatic analyses and RNAi we demonstrate that DjPiwiB-piRNA complexes are required for the proper expression of Djmcm2 and Djhistone h4 in neoblasts and that DjPiwiB-piRNA complexes regulate the transient expression of Djcalu during neoblast differentiation. Thus, DjPiwiB-piRNA complexes regulate the correct expression patterns during neoblast self-renewal and differentiation.