Paranko J, Pelliniemi L J, Vaheri A, Foidart J M, Lakkala-Paranko T
Department of Anatomy, University of Turku, Finland.
Differentiation. 1983;23 Suppl:S72-81. doi: 10.1007/978-3-642-69150-8_13.
The possible role of fibronectin in the organization of the sex-specific gonadal components was studied by immunocytochemistry combined with electron and light microscopy in rat fetuses at the ages of 12-15 days. Fibronectin was evenly distributed in both sexes under the basal lamina of the surface epithelium. Other basal laminae were not seen using light or electron microscopy inside the gonadal ridges at the age of 12 days. As the first sign of sexual differentiation, fibronectin-negative gonadal cords appeared in 13-day-old fetuses. In the males the cords were bigger than those in the females. The cords were clearly separated from the interstitium in 15-day-old fetuses of both sexes. A continuous layer of fibronectin had formed between the testicular surface epithelium and the elongated cords indicating the formation of a tunica albuginea. In females the surface epithelium-cord connection was maintained at all stages. Connections of the gonadal cords to mesonephric tubuli were seen in the rete region of both sexes. The electron optical basal lamina around the gonadal cords became continuous by the age of 15 days. The present results suggest that fibronectin is intimately involved in the sexual differentiation of the gonads, but not under the regulation of H-Y antigen or other testis-organizing factor.
采用免疫细胞化学结合电子显微镜和光学显微镜技术，对12至15日龄大鼠胎儿性腺特异性成分组织中纤连蛋白的可能作用进行了研究。纤连蛋白在表面上皮基膜下的两性中均呈均匀分布。在12日龄的性腺嵴内，用光镜或电镜均未观察到其他基膜。作为性别分化的首个迹象，13日龄胎儿出现了纤连蛋白阴性的性腺索。雄性的性腺索比雌性的更大。在15日龄的两性胎儿中，性腺索与间质明显分离。在睾丸表面上皮和伸长的性腺索之间形成了一层连续的纤连蛋白，表明白膜的形成。在雌性中，表面上皮与性腺索的连接在所有阶段均得以维持。在两性的网区域均可见性腺索与中肾小管的连接。到15日龄时，性腺索周围的电子光学基膜变得连续。目前的结果表明，纤连蛋白密切参与性腺的性别分化，但不受H-Y抗原或其他睾丸组织因子的调控。
