title: H3K36 Trimethylation-Mediated Epigenetic Regulation is Activated by Bam and Promotes Germ Cell Differentiation During Early Oogenesis in Drosophila.
abstract: Epigenetic silencing is critical for maintaining germline stem cells in Drosophila ovaries. However, it remains unclear how the differentiation factor, Bag-of-marbles (Bam), counteracts transcriptional silencing. We found that the trimethylation of lysine 36 on histone H3 (H3K36me3), a modification that is associated with gene activation, is enhanced in Bam-expressing cells. H3K36me3 levels were reduced in flies deficient in Bam. Inactivation of the Set2 methyltransferase, which confers the H3K36me3 modification, in germline cells markedly reduced H3K36me3 and impaired differentiation. Genetic analyses revealed that Set2 acts downstream of Bam. Furthermore, orb expression, which is required for germ cell differentiation, was activated by Set2, probably through direct H3K36me3 modification of the orb locus. Our data indicate that H3K36me3-mediated epigenetic regulation is activated by bam, and that this modification facilitates germ cell differentiation, probably through transcriptional activation. This work provides a novel link between Bam and epigenetic transcriptional control.
authors.affiliation: Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Institute for Integrative Neurobiology, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan mmukai01@center.konan-u.ac.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Mukai
authors.affiliation: Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Research Fellow of Japan Society for the Promotion of Science, Tokyo 102-0083, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Hira
authors.affiliation: Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan.
authors.forename: Shoichi
authors.initials: S
authors.lastname: Nakamura
authors.affiliation: Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kimura
authors.affiliation: Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan.
authors.forename: Masanao
authors.initials: M
authors.lastname: Sato
authors.affiliation: Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Kobayashi
keywords: Differentiation factor; Drosophila; Germ cell; Histone modification; Transcriptional control