Padua Maria B, Jiang Tianyu, Morse Deborah A, Fox Shawna C, Hatch Heather M, Tevosian Sergei G
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610.
Endocrinology. 2015 May;156(5):1873-86. doi: 10.1210/en.2014-1907. Epub 2015 Feb 10.
The roles of the GATA4 and GATA6 transcription factors in testis development were examined by simultaneously ablating Gata4 and Gata6 with Sf1Cre (Nr5a1Cre). The deletion of both genes resulted in a striking testicular phenotype. Embryonic Sf1Cre; Gata4(flox/flox) Gata6(flox/flox) (conditional double mutant) testes were smaller than control organs and contained irregular testis cords and fewer gonocytes. Gene expression analysis revealed significant down-regulation of Dmrt1 and Mvh. Surprisingly, Amh expression was strongly up-regulated and remained high beyond postnatal day 7, when it is normally extinguished. Neither DMRT1 nor GATA1 was detected in the Sertoli cells of the mutant postnatal testes. Furthermore, the expression of the steroidogenic genes Star, Cyp11a1, Hsd3b1, and Hsd17b3 was low throughout embryogenesis. Immunohistochemical analysis revealed a prominent reduction in cytochrome P450 side-chain cleavage enzyme (CYP11A1)- and 3β-hydroxysteroid dehydrogenase-positive (3βHSD) cells, with few 17α-hydroxylase/17,20 lyase-positive (CYP17A1) cells present. In contrast, in postnatal Sf1Cre; Gata4(flox/flox) Gata6(flox/flox) testes, the expression of the steroidogenic markers Star, Cyp11a1, and Hsd3b6 was increased, but a dramatic down-regulation of Hsd17b3, which is required for testosterone synthesis, was observed. The genes encoding adrenal enzymes Cyp21a1, Cyp11b1, Cyp11b2, and Mcr2 were strongly up-regulated, and clusters containing numerous CYP21A2-positive cells were localized in the interstitium. These data suggest a lack of testis functionality, with a loss of normal steroidogenic testis function, concomitant with an expansion of the adrenal-like cell population in postnatal conditional double mutant testes. Sf1Cre; Gata4(flox/flox) Gata6(flox/flox) animals of both sexes lack adrenal glands; however, despite this deficiency, males are viable in contrast to the females of the same genotype, which die shortly after birth.
通过使用Sf1Cre(Nr5a1Cre)同时敲除Gata4和Gata6,研究了GATA4和GATA6转录因子在睾丸发育中的作用。两个基因的缺失导致了显著的睾丸表型。胚胎期的Sf1Cre; Gata4(flox/flox) Gata6(flox/flox)(条件性双突变体)睾丸比对照器官小,包含不规则的睾丸索和较少的生殖母细胞。基因表达分析显示Dmrt1和Mvh显著下调。令人惊讶的是,Amh表达强烈上调,并且在出生后第7天之后仍保持高水平,而在正常情况下此时它会熄灭。在突变体出生后睾丸的支持细胞中未检测到DMRT1和GATA1。此外,在整个胚胎发育过程中,类固醇生成基因Star、Cyp11a1、Hsd3b1和Hsd17b3的表达都很低。免疫组织化学分析显示,细胞色素P450侧链裂解酶(CYP11A1)和3β-羟基类固醇脱氢酶阳性(3βHSD)细胞显著减少,只有少量17α-羟化酶/17,20裂解酶阳性(CYP17A1)细胞。相反,在出生后的Sf1Cre; Gata4(flox/flox) Gata6(flox/flox)睾丸中,类固醇生成标志物Star、Cyp11a1和Hsd3b6的表达增加,但观察到睾酮合成所需的Hsd17b3显著下调。编码肾上腺酶Cyp21a1、Cyp11b1、Cyp11b2和Mcr2的基因强烈上调,并且含有大量CYP21A2阳性细胞的簇位于间质中。这些数据表明睾丸功能缺失,正常的类固醇生成睾丸功能丧失,同时出生后条件性双突变体睾丸中肾上腺样细胞群体扩大。两性的Sf1Cre; Gata4(flox/flox) Gata6(flox/flox)动物都没有肾上腺;然而,尽管有这种缺陷,但与相同基因型的雌性动物出生后不久死亡相反,雄性动物是存活的。