青鳉gsdf调控Igf2bp2/Igf2bp3-m6A阅读器在雌雄生殖细胞的差异表达

Medaka gsdf Regulates Differential Expression of Igf2bp2/Igf2bp3-m6A Reader in Male and Female Germ Cells

青鳉gsdf敲除导致生殖细胞异常增殖,产生XY巨大精巢或XY巨大卵巢。正常精巢、卵巢及gsdf缺失型XY巨大精巢或巨大卵巢的mRNA转录组比对分析和qPCR验证结果显示,igf2bp2表达可能受gsdf信号调控。脊椎动物igf2bp2的分子结构高度进化保守,igf2bp2 mRNA在胚胎发育各时期均有表达,在成体精巢表达量最高,提示igf2bp2可能在早期胚胎发育、性别分化及精子生成发育中起重要作用。免疫荧光检测显示XY精巢的抗Igf2bp2免疫反应信号强于XX卵巢、gsdf缺失型XY精巢和XY卵巢。不同于gsdf缺失激活igf2bp3的表达,gsdf缺失反而减弱igf2bp2表达。Gsdf对igf2bp2和igf2bp3的正负调控影响其介导的m6A甲基腺苷修饰,以及其靶向的mRNA转录后修饰和翻译,这一分子调控机制可能在脊椎动物性别分化和精子生成过程中普遍存在。

Knockout of gonadal soma-derived factor(gsdf),led to the abnormal proliferation of germ cells and sexual reversal of XY males to females.Differences in transcriptome data of wild-type XY testis,XX ovary,and gsdf-deficient XY giant testis or XY giant ovary showed that the expression level of igf2bp2(insulin-like growth factor 2 mRNA binding protein 2)was significantly higher in wild-type XY sperms than that in wild-type XX ovary and gsdf-deficient XY sperms and XY ovary,and confirmed by RT-qPCR,suggesting that igf2bp2 expression may be regulated by gsdf signal.The molecular structure of vertebrate igf2bp2 was highly homology evolutionary conserved.RT-qPCR showed that igf2bp2 mRNA was highly expressed in early embryogenesis,especially in the stage of gastrulation.The expression of igf2bp2 was in early embryogenesis and predominant testis in adulthood,suggesting that igf2bp2 may play an important role in early embryonic development,sex differentiation and spermatogenesis.Immunofluorescence assay revealed that the signal of positive reaction of anti-Igf2bp2 antibody in wild-type XY testis was stronger than that of XX ovary,gsdf-deficient XY testis or XY ovary.The presence or absence of gsdf signaling was positively correlated with igf2bp2 expression during gonadal developmental differentiation in medaka,thus may potentially promote igf2bp2 expression,which was opposite to the inhibition of igf2bp3 expression.gsdf-regulatory role of igf2bp2/igf2bp3 expression during medaka spermatogenesis may be a conserved molecular mechanism in vertebrate gonadal differentiation and spermatogenesis.