title: Mitf is a transcriptional activator of medaka germ genes in culture.
abstract: Germ cells express a unique subset of genes called germ genes mostly encoding RNA-binding proteins such as Dazl, Dnd and Vasa. How germ gene expression is controlled remains illusive, because in no organism has a transcription factor been identified that regulate expression of these genes. Microphthalmia-associated transcription factor (Mitf) has been reported to show expression in male mouse germ cells of the adult testis. Here we report in the fish medaka (Oryzias latipes) that Mitf is a transcription activator of germ gene expression. Mitf is a master regulator of melanocyte development, which activates melanogenic genes through binding to the E-box containing consensus CANNTG. The E-box was found to be present in 23-26 copies in the promoters of medaka germ genes dazl, dnd and vasa. Importantly, forced Mitf expression enhanced the transcriptional activity of the three gene promoters by up to more than 10 fold and remarkably increased the level of endogenous dazl, dnd and vasa transcripts in cell culture. Transfection of Mitf expression vectors was sufficient to induce directed differentiation of medaka embryonic stem cells into melanocytes. Fluorescence in situ hybridization revealed the expression of both medaka mitf genes in adult germ cells of male and female gonads. Mitf is well-known as the melanocyte master regulator. Our results offer first evidence that Mitf may act as a transcriptional activator of germ gene expression in medaka.
authors: Department of Biological Sciences, National University of Singapore, Science Drive 4, Singapore 117543, Singapore.
authors: Haobin
authors: H
authors: Zhao
authors: Mingyou
authors: M
authors: Li
authors: Yovita Ida
authors: YI
authors: Purwanti
authors: Rong
authors: R
authors: Liu
authors: Tiansheng
authors: T
authors: Chen
authors: Zhendong
authors: Z
authors: Li
authors: Ni
authors: N
authors: Hong
authors: Guijun
authors: G
authors: Guan
authors: Ao
authors: A
authors: Yin
authors: Ling
authors: L
authors: Xiao
authors: Ruowen
authors: R
authors: Ge
authors: Jianxing
authors: J
authors: Song
authors: Yunhan
authors: Y
authors: Hong
mesh_terms: D000818:Animals; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics / Q000378:metabolism*; D009990:Oryzias / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013737:Testis / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D051739:Microphthalmia-Associated Transcription Factor