Testis-like development of gonads in female moles.: New insights on mammalian gonad organogenesis
Testis-like development of gonads in female moles.: New insights on mammalian gonad organogenesis
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DOI：
10.1016/j.ydbio.2003.11.025
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发表时间：
2004-04-01
影响因子：
2.7
通讯作者：
Jiménez, R
中科院分区：
文献类型：
--
作者：
Barrionuevo, FJ;Zurita, F;Jiménez, R
鼹鼠在哺乳动物中是独一无二的，因为几种Talpa属的所有雌性都有双侧卵睾丸（性腺有卵巢和睾丸组织）。基于对13年多的胚胎、胎儿和婴儿的大样本分析，我们研究了Talpa oceanentalis物种的雄性和雌性鼹鼠的性腺发育。专门开发了几种新的现场和实验室程序，以获得和管理这种奇异的材料。我们的研究结果表明，雌性鼹鼠的性腺发育按照睾丸样模式，其中包括索形成和中肾细胞迁移，并开始在同一时间作为睾丸分化的队友。性别分化的最初迹象并不出现在男性身上，而是出现在女性身上。雌性（而非雄性）性腺由皮质（卵巢组织的前体）和髓质（睾丸组织的前体）区域化。生殖细胞只集中在皮层，所以髓质很快就变得不育。女性睾丸组织发育在出生前约一周短暂延迟，之后恢复。雌性卵巢组织的发育相对于雄性和雌性的睾丸组织的发育要延迟得多。不包括睾丸的管周肌样细胞的分子特征证明了雌性鼹鼠性腺中存在睾丸组织，其中也含有Leydig细胞。然而，完全分化的支持细胞的缺乏表明这些细胞不负责触发这种睾丸组织的分化。我们的研究结果也讨论了支持细胞的形态和功能的定义，以及生殖细胞在性逆转过程中可能发挥的作用。XX和XY性腺发育摩尔之间观察到的差异表明，哺乳动物睾丸决定基因，SRY，具有“反区域化”的作用，在性腺发育过程中，至少在这些哺乳动物物种中，区域化的女性性腺发生。(C)2004年爱思唯尔公司All rights reserved.
Moles are unique among mammals because all females of several species of genus Talpa have bilateral ovotestes (gonads with both ovarian and testicular tissue). Based on the analysis of a large sample of embryos, foetuses and infants over a 13-year period, we have studied the development of the gonads in male and female moles of the species Talpa occidentalis. Several new field and laboratory procedures were developed specifically to obtain and manage this singular material. Our results reveal that gonads of female moles develop according to a testis-like pattern, which includes cord formation and mesonephric cell migration, and begins at the same time as testis differentiation in mates. The first signs of sex differentiation do not appear in males but in females. Female (but not male) gonads are regionalised with a cortex (precursor of the ovarian tissue) and a medulla (precursor of the testicular tissue). Germ cells concentrate only in the cortex, so that the medulla soon becomes sterile. Testicular tissue development is transiently retarded in females for about a week before birth, and resumes afterwards. Development of the ovarian tissue in females is considerably delayed with respect to that of testicular tissue in both males and females. The molecular characterisation of peritubular myoid cells, which are exclusive of testes, evidences the presence of testicular tissue in the gonads of female moles, which also contain Leydig cells. However, the absence of fully differentiated Sertoli cells indicates that these cells are not responsible for triggering the differentiation of such a testicular tissue. Our results are also discussed regarding the definition of Sertoli cell morphology and function, and the possible role of germ cells in the sex-reversal process. Differences observed between XX and XY gonad development in moles suggest that the mammalian testis-determining gene, SRY, has an "anti-regionalisation" role during gonadal development, at least in those mammalian species in which regionalisation of the female gonad occurs. (C) 2004 Elsevier Inc. All rights reserved.