Sex- determining mechanisms in anurans

1. 在日本广泛分布的林蛙性染色体（No. 7）分为4个类群，即异型(1)东北（ZW型）和(2)东南（XY型）类群，同态(3)关东和(4)西日本类群。通过对睾酮治疗性逆转的研究，发现关东和西日本人群的性别决定机制为XY型。在东北种群（ZW型）和东南种群（XY型）中，激素治疗未发生性逆转死亡。在广崎（ZW）和熊野（XY）种群的互交杂交中，ZY和ZX为雄蛙，WY和WX为雌蛙。在新潟种群（ZW）和滨下种群（XY）中，ZY为雄蛙，ZX为雌蛙或雄蛙。WX和WY几乎都是雌性。黑斑田鼠的Hiro和Kumano种群以及部分Kaita种群和短脚田鼠的冈山种群中，第4号染色体上的前决定基因有5个以上，雄性为异配型。部分凯塔群体在3号和4号染色体上没有性别决定基因。短足田梅原居群在第3号染色体上有性别决定基因，雄性为异配型。在日本龙蛙广崎种群中，通过c显带法发现第4号染色体为性染色体，而在广岛两个种群中，性染色体未被区分，且在第4号染色体上未发现雄性决定基因。在10个日本稻属群体中，有7个西日本群体的性别决定基因与Ab基因连锁，而在东日本的一关和富山群体中，性别决定基因与Ab和MPI基因均不连锁。Okutama的樱鲤雄性为异配子，8号染色体形态鉴定为性染色体。在来自奥间、柴田、金西罗和广崎的田家蚕中未发现性染色体。少

1. The sex chromosomes (No. 7) of Rana rugosa distributed widely in Japan, are divided into four groups, the heteromorphic (1) northeastern (ZW type) and (2) southeastern (XY) populations, and the homomorphic (3) Kanto and (4) west Japan populations.2. It was found that the Kanto and the West Japan populations are the XY type in sex-determining machanism from the study of sex reversal by the testosterone treatment. In the northeastern populations (ZW type) and southeastern populations (XY type), sex reversal died not occur by the hormone treatment.3. In reciprocal hybrids between the Hirosaki (ZW) and Kumano (XY) populations, ZY and ZX frogs were males and WY and WX frogs were famales. Between the Niigata (ZW) and Hamakita populations (XY), ZY frogs were males and ZX frogs were either females or males. WX and WY frogs were almost females.4. In the Hiro and Kumano populations and a part of the Kaita population of Rana nigromaculata and the Okayama population of R.brevipoda, there were s … More ex-determining genes on chromosome No. 4, and the male was heterogametic. A part of the Kaita population did not have sex-determining gene on the chromosomes Nos. 3 and 4. The Maibara population of R.brevipoda had sex-determining gene on chromosome No. 3 and the male was heterogametic.5. In the Hirosaki population of Rana Japonica, that chromosome No. 4 was found to be the sex chromosome by the C-banding method, while the sex chromosome was not distinguished in the two Hiroshima populations and it was found that there was no male-determining gene in chromosome No. 4. In seven West Japan populations out of ten populations of R.japonica, the sex-determining gene was linked with Ab gene, while in the Ichinoseki and Toyama populations of East Japan, the sex-determining gene linked neither Ab nor MPI genes.6. Rena sakuraii from Okutama was heterogametic in males and chromosome No. 8 was identified morphologically as sex chromosomes. In R.tagoi from Okutama, Shibata, Kanashiro and Hirosaki, no sex-chromosome were found. Less