ARTIFICIAL INDUCTION OF FUNCTIONAL SEX-REVERSAL IN GENOTYPIC FEMALES OF THE MEDAKA (ORYZIAS-LATIPES)
ARTIFICIAL INDUCTION OF FUNCTIONAL SEX-REVERSAL IN GENOTYPIC FEMALES OF THE MEDAKA (ORYZIAS-LATIPES)
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DOI：
10.1002/jez.1401370203
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发表时间：
1958-01-01
影响因子：
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通讯作者：
YAMAMOTO, T
中科院分区：
文献类型：
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作者：
YAMAMOTO, T
使用经遗传分析的鱼类品种（青鳉，青鳉），从中性性腺阶段开始口服甲基睾酮，并持续通过性腺性别分化期，之后以正常饮食饲养经处理的鱼至完全生长。性连锁的R（橙红色）和r（白色）性状被用作性染色体的标记，以区分性基因型。甲基睾酮对性腺发生产生抑制作用，与性别基因型无关，并诱导遗传雌性性腺性别分化逆转（XrXr）。发现适当剂量水平的范围很窄，睾丸通常是非典型的。在任何给药组中均未观察到反常雌性化。在高剂量下，任一遗传性别（XrYR）的鱼苗首先分化为具有退化睾丸的雄性，最终在完全发育的鱼中变成中性（无性别）。在中等和较低剂量下，迄今为止获得了95个成熟的性反转雄性和3个雌性基因型（XrXr）的中间性。大部分的性反转（Xrxr）诱导足够的剂量是可育的，而其余的被证明是不育的交配，有一个睾丸，其中含有受精精子，在人工受精证明。27个性反转雄性分别与正常雌性（XrXr）杂交产生全雌性F1后代，共1，376个。在遗传行为上，性反转的F1代白色女儿与正常的白色女性是一样的。
Using a genetically analyzed fish breed (the medaka, Oryzias latipes), methyl testosterone is administered per os beginning with the stage of indifferent gonad and continuing through the period of gonadal sex-differentiation, after which treated fish are reared on normal diet to full growth. Sex-linked R (Orange-red) and r (White) characters are used as markers of the sex-chromosomes in order to distinguish the sex genotype. Methyl testosterone exerts a suppression of gonadogenesis irrespective of the sex genotype, and induces reversal of gonadal sex-differentiation in genetic females (XrXr). The range of adequate dosage levels is found to be narrow and testes are usually atypical in form. No paradoxical feminization is observed in any treated groups. With high-level dosages, fry of either genetic sex (XrYR) first differentiate into males with rudimentary testis eventually becoming neuter (sexless) in full-grown fish. With moderate and lower dosages, so far 95 mature sex-reversal males and three intersexes of the female genotype (XrXr) are obtained. The majority of sex-reversals (Xrxr) induced by adequate dosages are fertile while the rest are proved sterile in mating only, having a testis which contains fecund spermatozoa, as is proved in artificial fertilization. Twenty-seven sex-reversal males crossed separately with normal females (XrXr) produced all-female F1 progenies, a total of 1,376. In genetic behavior, the F1 white daughters of sex-reversals are the same as normal white females.