Nakamura Shuhei, Aoki Yumiko, Saito Daisuke, Kuroki Yoko, Fujiyama Asao, Naruse Kiyoshi, Tanaka Minoru
Laboratory of Molecular Genetics for Reproduction, National Institute for Basic Biology, Okazaki, Japan.
Mol Reprod Dev. 2008 Mar;75(3):472-6. doi: 10.1002/mrd.20764.
We have established an enhanced green fluorescent protein (EGFP) transgenic medaka line that mimics the expression of sox9b/sox9a2 to analyze the morphological reorganization of the gonads and characterize the sox9b-expressing cells during gonadal formation in this fish. After the germ cells have migrated into the gonadal areas, a cluster of EGFP-expressing cells in the single gonadal primordium was found to be separated by the somatic cells along the rostrocaudal axis and form the bilateral lobes. We observed in these transgenic fish that EGFP expression persists only in the somatic cells directly surrounding the germ cells. As sex differentiation proceeds, dmrt1 and foxl2 begin to be expressed in the EGFP-expressing cells in the XY and the XX gonads, respectively. This indicates that the sox9b-expressing cells reorganize into two lobes of the gonad and then differentiate into Sertoli or granulosa cells, as common precursors of the supporting cells. Hence, our sox9b-EGFP medaka system will be useful in future studies of gonadal development.
我们建立了一种增强型绿色荧光蛋白（EGFP）转基因青鳉鱼品系，该品系模拟sox9b/sox9a2的表达，以分析性腺的形态重组，并在这种鱼类性腺形成过程中对表达sox9b的细胞进行特征描述。生殖细胞迁移到性腺区域后，在单个性腺原基中发现一群表达EGFP的细胞沿着头尾轴被体细胞分隔开，形成双侧叶。我们在这些转基因鱼中观察到，EGFP仅在直接围绕生殖细胞的体细胞中持续表达。随着性别分化的进行，dmrt1和foxl2开始分别在XY和XX性腺中表达EGFP的细胞中表达。这表明表达sox9b的细胞重组形成性腺的两个叶，然后分化为支持细胞的共同前体——支持细胞或颗粒细胞。因此，我们的sox9b-EGFP青鳉鱼系统将对未来性腺发育的研究有用。
