Vasa基因在斑马鱼不同发育时期的mRNA表达分析

Vasa mRNA expression pattern in different gonadal development stage of zebrafish

Vasa基因在果蝇中首次报道后,作为不同物种早期原始生殖细胞(PGC)标记基因被普遍接受。但对其研究都集中于早期胚胎,对性腺分化及成熟时期的Vasa表达及功能少有研究。RT-PCR结果显示,Vasa基因在整个发育阶段的表达量先上升再下降。荧光定量PCR结果显示,在同一发育时期,精巢、卵巢表达量基本一致,卵巢略高于精巢。mRNA原位杂交显示,Vasa基因早期在斑马鱼生殖干细胞特异表达,随后在精巢表达于精原细胞和初级精母细胞,在卵巢表达于Ⅲ、Ⅳ、Ⅴ时相卵母细胞。研究结果有助于鉴定斑马鱼生殖干细胞和进一步研究性分化和逆转的细胞机制。

Since first reported in Drosophila, Vasa gene had been widely accepted as a good molecular marker of primordial germ cells in various species. So far the reserch had largely focused on early embyo development. The expression of Vasa gene in gonad differentiation stage and mature stage was rarely known. In this paper, we employed RT-PCR analysis and found that Vasa gene mRNA first increased and then decreased during gonad development. Real-time RT PCR analysis showed that the expression level of Vasa gene in ovary was similar or a little higher than that in testis, mRNA in situ hybridization showed that Vasa gene was specially detected in zebrafish PGCs, spermatogonia, and primary spermatocyte in immaturate and mature testis. In mature ovary, vasa mainly expressed in vitellogenic granules of III, IV, V phase oocytes. This study would facilitate us to identify germ stem ceils in gonadal tissues and to deeply understand cellular mechanisms of sex differentiation and sex reversal.