Effects of embryonic treatment with fadrozole on phenotype of gonads, syrinx, and neural song system in zebra finches
Effects of embryonic treatment with fadrozole on phenotype of gonads, syrinx, and neural song system in zebra finches
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DOI：
10.1006/gcen.1999.7318
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发表时间：
1999-09-01
影响因子：
2.7
通讯作者：
Arnold, AP
中科院分区：
文献类型：
--
作者：
Gong, A;Freking, FW;Arnold, AP
先前的研究发现，在孵育的第5天或第8天用芳香酶抑制剂处理斑胸草雀胚胎会导致雌性性腺表型的部分性别逆转。这些雌性同时拥有睾丸和卵巢组织，歌唱神经回路的发育仍然是女性化的。本研究通过在孵育第3天使用芳香酶抑制剂Fadrozole （CGS 16949A）或生理盐水更早地处理斑胸草雀胚胎，试图实现更彻底的性腺逆转。我们研究了100日龄鸟类的鸣管（雄激素依赖性发声器官）、性腺和端脑神经鸣叫系统的表型。接受治疗的雌性通常有左卵睾丸和右睾丸，注射器比对照组大得多。处理后雌鼠睾丸组织的组织学和类固醇合成酶活性与对照组相似，具有较强的男性化特征。在牺牲时，服用法地唑的雌鼠血浆睾酮和雌二醇浓度与对照组没有差异，但服用法地唑的雌鼠血浆双氢睾酮浓度较低。尽管有大量的功能性睾丸组织和男性化的喉管，但雌性雌鼠的歌唱系统核（HVC， RA）的体积和体细胞大小仍保持女性化。这些结果表明，睾丸分泌物使鸣管雄性化，但不足以使鸣叫系统雄性化。(C) 1999学术出版社。
Previous studies have found that treatment of zebra finch embryos with an aromatase inhibitor on Day 5 or 8 of incubation caused partial sex reversal of gonadal phenotype in females. These females possessed both testicular and ovarian tissue, and the development of the neural circuit for song remained feminine. The present study attempted more complete gonadal reversal by treating zebra finch embryos earlier, on Day 3 of incubation, with Fadrozole (CGS 16949A), an aromatase inhibitor, or with saline. We examined the phenotype of the syrinx (androgen-dependent vocal organ), the gonads, and the telencephallic neural song system in 100-day-old birds. Treated females typically possessed a left ovotestis and a right testis, and significantly larger syringes than control females. The histology and steroid synthetic enzyme activity of the testicular tissue in treated females were quite masculine and similar to that of control males. At the time of sacrifice, the plasma concentrations of testosterone and estradiol for fadrozole-treated females did not differ from those of control females, but dihydrotestosterone was lower in treated females. Despite the large amount of functional testicular tissue and a masculine syrinx, the volumes and soma sizes of song system nuclei (HVC, RA) in treated females remained feminine. These results suggest that testicular secretions masculinize the syrinx, but are not sufficient to masculinize the song system in zebra finches. (C) 1999 Academic Press.