Analyses of the involvement of LTR-transposon in meiotic regulation of mammalian oocytes.

2013 Fiscal Year Final Research Report

• Project/Area Number: 24658232
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Applied animal science
• Research Institution: The University of Tokyo
• Principal Investigator: NAITO Kunihiko 東京大学, 農学生命科学研究科, 教授 (20188858)
• Project Period (FY): 2012-04-01 – 2013-03-31
• Keywords: 応用動物 / 畜産学 / 卵成熟 / レトロトランスポゾン / MAEL

Research Abstract

Possible involvement of LTR-transposable elements (Te), which are thought to be parasite genes in mammalian genom, in meiotic regulation of mammalian oocytes were analyzed using porcine oocytes and Maelstrom (MAEL), which was shown in testis to be involved in the biosynthesis of piRNA, an inhibitor of LTR-Te. Porcine MAEL cDNA was cloned from porcine oocytes and found that the molecular weights of porcine MAEL were different between oocyte and testis. In porcine oocytes, MAEL mRNA was present throughout meiosis and MAEL protein was decreased according with the progression of meiosis. MAEL functions on meiotic maturation were analyzed by artificial expression control of MAEL protein using MAEL mRNA or antisense RNA injection into oocytes. However, there were no effects on microtubule organization and meiotic progression during oocyte maturation. Therefore, I cannot provide the evidence showing the involvement of MAEL, and subsequently LTR-Te, in meiotic regulation of porcine oocytes.