Graduate School of Frontier Biosciences, Osaka University

Japanese

Colloquium 221

Speaker Shinpei Yamaguchi (Assistant professor / Graduate school of Medicine, Osaka University (Nakano Lab.)
Title Molecular mechanism and developmental role of the heterochromatin remodeling in mouse primordial germ cell”
Speaker Kanako Kita (Japan society for the promotion of science ・RPD / FBS Stem cell pathology, Osaka University(Nakano Lab.)
Title Identification and functional analysis of MIWI2 binding partner in embryonic male germ cells.”
Date Thu., Sept. 12, 2019, 12:15~13:00
Place 2F Seminar room, BioSystems Building
Host Name:Shipnei Yamaguchi    
Tel :06-6879-3722
E-mail:yamaguchi@patho.med.osaka-u.ac.jp
Language Japanese












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Title/Abstract

Molecular mechanism and developmental role of the heterochromatin remodeling in mouse primordial germ cell”

The pericentromeric region surrounding centromere maintains a highly condensed constitutive heterochromatin state throughout cell division and development. On the other hand, drastic changes in heterochromatin, including genome-wide demethylation, take place in primordial germ cells, which give rise to eggs and sperm. It was not clear how constitutive heterochromatin changes during epigenetic reprogramming, and how these changes play a role in normal development. We found that the pericentromeric regions of primordial germ cells underwent "heterochromatin remodeling" that acquire facultative heterochromatin-like characteristics. Analyses using ES cells and Tet1-deficient mice demonstrated that heterochromatin remodeling occurs in a Tet1-dependent manner and functions in pericentromere clustering. Pericentromere clustering occurs during meiotic prophase is essential for the normal meiotic process. Heterochromatin remodeling by Tet1 has been suggested to be a key factor in the progression of meiosis under hypomethylation state. In this seminar, I would like to introduce and discuss the novel functions of Tet1.

Identification and functional analysis of MIWI2 binding partner in embryonic male germ cells.”

Small RNAs have critical roles for gene regulations and these abnormalities often lead to developmental arrest and/or diseases. Among small RNAs, we have focused on germ cell specific small RNA, named piRNA (PIWI-interacting RNA). piRNA functions as “genomic guardian” by repressing retrotransposon, and are essential for germ cell developments. Mouse piRNA binding protein, MILI (Mouse PIWI like) and MIWI2 (Mouse PIWI2) have critical roles for piRNA biogenesis and its function, respectively. We have shown that majority of piRNA are derived from retrotransposons and they contributed for retrotransposon silencing by DNA methylation. In this seminar, we introduce recent findings in our lab about “The role of MORC3 newly identified as MIWI2 binding partner in embryonic male germ cells”.


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