メダカ卵巣における性分化開始部位について〔英文〕

概要

論文の詳細を見る
The gradient of the ovarian differentiation in the medaka, Oryzias latipes, was examined numerically in the present investigation. Germ cell in meiosis was employed as a criterion for the differentiation of ovary. In the fry of 4.9±0.10mm in length (mean±S. D., n=30) at 2 days (26±2h) after hatching, the germ cells in meiotic prophase were detected for the first time, but the somatic cells of the ovary showed no structural differentiation, According to YAMAMOTO, there was an antero-posterior gradient in the gonadal sex differntiation of the medaka. In the present investigation, however, such a gradient was not recognizable. The ovarian differentiation proceeded at random without any gradient. From the present results, it was revealed that the ovarian differentiation began before the completion of the formation of the primordial gonad, and that there was a difference in the time of the differentiation between the right lobe and the left lobe of the ovary; the right lobe differentiated at an earlier stage than the left lobe.
日本水産學會の論文