Identification and characterization of transposable element-regulating small RNAs

2014 Fiscal Year Final Research Report

• Project/Area Number: 25830134
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Genome biology
• Research Institution: Keio University
• Principal Investigator: IWASAKI Yuka 慶應義塾大学, 医学部, 助教 (80612647)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 小分子RNA / トランスポゾン / 遺伝子発現抑制 / 生殖組織 / 非コードRNA / RNAサイレンシング

Outline of Final Research Achievements

Small RNAs mediate transposable element (TE) silencing by binding Argonaute/Piwi proteins. Here, we describe small RNA profiling of the adult testes of Callithrix jacchus, a model primate. We identified 353 novel miRNAs, which some originated from TEs. Meanwhile, the most abundant class of small RNAs in the adult testis was piRNAs. Therefore, we generated an antibody for MARWI, a marmoset PIWI protein, and performed high throughput sequencing analysis. MARWI-piRNAs show characteristics of mouse pachytene piRNAs, and are mostly derived from conserved clustered regions in the genome, known as pIRNA clusters. Further analysis revealed that strand bias observed for piRNAs mapped to each TE subfamily correlates with the polarity of TE copies inserted in clusters. Also, more piRNAs map to TE subfamilies when they have copies in piRNA clusters. These findings suggest that TE insertions to pachytene piRNA clusters determine abundance and strand-bias of TE-derived piRNAs.

Free Research Field

分子生物学，ゲノム生物学