Merchant-Larios R, Villalpando I
Anat Rec. 1981 Mar;199(3):349-60. doi: 10.1002/ar.1091990305.
The establishment of the undifferentiated gonad was studied in Xenopus laevis and Rana pipiens using high resolution techniques. It was found that the cells of the so-called "mesonephric blastema" had no structural resemblance to the cells of the gonadal medulla in both species. Furthermore, there was no morphological evidence that would suggest a migration of the former cells towards the incipient gonad at the time of its appearance. However, the basal lamina of the coelomic epithelium was interrupted in the region of the genital crest, and there was a definite ultrastructural similarity between the cells of this epithelium and those that first form the medulla. These observations suggest that, in amphibians, the cells of the gonadal medulla come from a cellular line arising from the coelomic epithelium and not from the "mesonephric blastema," as has been proposed.
利用高分辨率技术，对非洲爪蟾和豹蛙未分化性腺的形成进行了研究。结果发现，在这两个物种中，所谓的“中肾胚基”细胞与性腺髓质细胞在结构上没有相似之处。此外，没有形态学证据表明在性腺初现之时，前者的细胞会向性腺迁移。然而，生殖嵴区域的体腔上皮基膜中断，并且该上皮细胞与最初形成髓质的细胞之间存在明确的超微结构相似性。这些观察结果表明，在两栖动物中，性腺髓质细胞来自体腔上皮产生的细胞系，而非如之前所提出的来自“中肾胚基”。
