Influence of the immature testis on sexual differentiation in the tammar wallaby, Macropus eugenii (Macropodidae: Marsupialia).
Influence of the immature testis on sexual differentiation in the tammar wallaby, Macropus eugenii (Macropodidae: Marsupialia).
复制标题
未成熟睾丸对塔玛袋鼠，Macropus eugenii（Macropodidae：Marsupialia）性别分化的影响。
DOI：
10.1071/rd9890243
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
L. Hinds
中科院分区：
文献类型：
--
作者：
CH Tyndale;L. Hinds
尤金袋鼠（Macropus eugenii，德斯马雷斯特命名）雌性的繁殖具有很强的季节性，而雄性则没有。本研究旨在确定这种差异是否在早期生命阶段因睾丸发育过程中的暴露情况而形成。出生后第10天，当可从外部辨别性别时，将雄性的睾丸取出并置于雌性的胁腹皮下，同时对其他组的雄性和雌性进行手术但不干扰性腺。睾丸移植物在3 - 6个月内可触及。通过核型分析确定了性染色体组成。在3岁时，接受睾丸移植的雌性的体重和身体尺寸与假手术雌性相比没有显著差异，而阉割的雄性体重和身体尺寸明显更大，且与假手术雄性相同，这表明在这种有袋类动物中，生长存在独立于睾丸的遗传控制。在5年的观察期间，接受睾丸移植的雌性无一繁殖后代，而从第二年起，所有假手术雌性每年都繁殖后代。接受睾丸移植的雌性具有雄性和雌性混合的生殖结构。育儿袋和乳腺正常发育，缪勒氏管衍生物、阴道复合体、子宫和输卵管也是如此。卵巢要么没有卵母细胞和卵泡，要么数量减少，中肾管在不同程度上得以保留，泌尿生殖索发育成一个在大小和结构上与完整雄性无法区分的前列腺，生殖结节发育成一个具有阴茎脚和考珀氏腺的正常大小的阴茎。在阉割的雄性中，阴囊正常发育，包含睾丸引带和输精管。没有缪勒氏管衍生物的迹象，泌尿生殖索是一个简单的管道，就像雌性一样。没有考珀氏腺，也没有阴茎或勃起组织。在一只半阉割的雄性中，没有阴茎发育，尽管剩余的睾丸占据阴囊并表现出代偿性肥大。这些发现表明，出生第10天的睾丸对中肾管、前列腺和阴茎的早期分化有深远影响，但不能影响缪勒氏管衍生物的分化。睾丸对育儿袋、乳腺或阴囊的发育以及身体生长没有任何影响，所有这些显然都受到独立的遗传控制。
Reproduction in the tammar wallaby, Macropus eugenii (Desmarest), is highly seasonal in the females but not the males. This study was designed to determine whether the difference is established during early life as a result of exposure to the developing testes. At day 10 after birth, when the sex can be distinguished externally, testes were removed from males and placed under the flank skin of females, while other groups of males and females were subjected to surgery without interfering with the gonads. The testis grafts remained palpable for 3-6 months. Sex-chromosome constitution was confirmed by karyotyping. At 3 years of age, the body weights and dimensions of the grafted females were not significantly different from those of the sham-operated females, whereas those of the castrated males were significantly larger and were equal to those of the sham-operated males, indicating that there is genetical control of growth independent of the testis in this species of marsupial. During 5 years of observations, none of the grafted females ever produced young, whereas all of the sham-operated females produced young each year from the second year. The grafted females had a mixture of male and female reproductive structures. The pouch and mammary glands developed normally, as did the Mullerian duct derivatives, the vaginal complex, the uteri and the oviducts. The ovaries were either devoid of oocytes and follicles or had reduced numbers, the Wolffian ducts were retained to varying degrees, the urogenital strand had developed into a prostate indistinguishable in size and structure from that of intact males, and the genital tubercle had developed into a normal-sized penis with a crus penis and Cowper's glands. In the castrated males, the scrotum developed normally and contained the gubernaculum and vas deferens. There was no evidence of Mullerian duct derivatives, and the urogenital strand was a simple canal, as in females. There were no Cowper's glands and no penis or erectile tissue. In one hemicastrated male, there was no development of the penis, although the remaining testis occupied the scrotum and showed compensatory hypertrophy. These findings indicate that the testis, at day 10, has a profound influence on the early differentiation of the Wolffian ducts, prostate and penis but cannot influence the differentiation of the Mullerian duct derivatives. The testis does not have any effect on the development of the pouch, mammary glands or scrotum or on somatic growth, all of which are apparently under independent genetical control.