Hatano O, Takakusu A, Nomura M, Morohashi K
Department of Anatomy, Nara Medical University, Japan.
Genes Cells. 1996 Jul;1(7):663-71. doi: 10.1046/j.1365-2443.1996.00254.x.
Ad4BP/SF-1 was originally identified as a steroidogenic tissue-specific transcription factor. Recent gene disruption studies with the mammalian Ftz-F1 gene encoding Ad4BP/SF-1 clearly revealed the essential function of the factor for adrenal and gonadal differentiation.
In this study, we examined the early development of these tissues using Ad4BP/SF-1 as the marker. In rat foetuses of 11.5 days post-coitum (d.p.c.), a cell population designated adrenogenital primordium was firstly observed on symmetrical lines extending from the dorsal aorta to the dorsal coelomic epithelia of the primitive urogenital ridges. From 12.5 d.p.c., the rostral half of the adreno-genital primordium started to separate into two distinct cell populations. Judging from the distribution of primordial germ cells, the cell population on the dorsal aortal side is a primordium for the adrenal cortex whereas that on the coelomic epithelial side is for the gonads. At 13.5 d.p.c., these two primordia have separated completely.
These observations clearly identified a novel adreno-genital primordium from which both the adrenal cortex and the gonads originate. An RT-PCR study conducted to detect adrenal- and gonad-specific mRNAs supported the above observations.
Ad4BP/SF-1最初被鉴定为一种类固醇生成组织特异性转录因子。最近对编码Ad4BP/SF-1的哺乳动物Ftz-F1基因进行的基因敲除研究清楚地揭示了该因子对肾上腺和性腺分化的重要功能。
在本研究中，我们以Ad4BP/SF-1作为标志物来研究这些组织的早期发育。在妊娠11.5天（d.p.c.）的大鼠胎儿中，首次在从背主动脉延伸至原始泌尿生殖嵴背侧体腔上皮的对称线上观察到一个被称为肾上腺生殖原基的细胞群。从12.5 d.p.c.开始，肾上腺生殖原基的头侧半部分开始分离为两个不同的细胞群。从原始生殖细胞的分布判断，背主动脉侧的细胞群是肾上腺皮质的原基，而体腔上皮侧的细胞群是性腺的原基。在13.5 d.p.c.时，这两个原基已完全分离。
这些观察结果明确鉴定出一种新的肾上腺生殖原基，肾上腺皮质和性腺均起源于此。为检测肾上腺和性腺特异性mRNA而进行的逆转录聚合酶链反应（RT-PCR）研究支持了上述观察结果。
