Cloning of the zebra finch androgen synthetic enzyme CYP17: A study of its neural expression throughout posthatch development
Cloning of the zebra finch androgen synthetic enzyme CYP17: A study of its neural expression throughout posthatch development
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DOI：
10.1002/cne.10936
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发表时间：
2003-12-22
影响因子：
2.5
通讯作者：
Schlinger, BA
中科院分区：
文献类型：
--
作者：
London, SE;Boulter, J;Schlinger, BA
雄性斑胸草雀有一个强大的神经系统来支持歌唱，但雌性斑胸草雀只有一个最小的歌唱回路，而且不唱歌。雌激素使歌曲回路雄性化，在孵化后的前3周发育中尤其有效。性腺似乎不提供雄性化类固醇，这意味着另一个组织合成类固醇。有证据表明，大脑能够合成神经类固醇，这在斑马雀的发育中可能是鸣唱系统分化所必需的。芳香化酶是一种从雄激素合成雌激素的酶，在男性和女性的大脑中同样丰富。为了进一步研究斑胸草雀脑中神经类固醇生成的潜力，我们克隆并检测了17 α-羟化酶/17，20裂解酶（CYP 17）的表达，CYP 17是合成芳香化酶的雄激素底物的酶。我们使用了北方印迹，逆转录-聚合酶链反应，原位杂交，以显示CYP 17在发育和成人大脑转录。CYP 17在发育阶段和大脑区域转录，对发育中的歌曲系统可能很重要，尽管在mRNA水平上没有检测到性别差异。我们的研究结果支持神经类固醇可能影响斑胸草雀大脑组织和功能的假设。(C)2003 Wiley-Liss，Inc.
Male zebra finches develop a robust neural song system that supports singing, but females have a minimal song circuit and do not sing. Estrogens masculinize the song circuit and are especially potent during the first 3 weeks of posthatch development. The gonads do not seem to supply the masculinizing steroids, implying that another tissue synthesizes steroids. Evidence suggests that the brain is capable of synthesizing neurosteroids, which in developing zebra finches may be required for song system differentiation. Aromatase, the enzyme that synthesizes estrogen from androgen, is equally abundant in male and female brains. To investigate further the potential for neurosteroidogenesis in the zebra finch brain, we cloned and examined the expression of 17alpha-hydroxylase/17,20 lyase (CYP17), the enzyme that synthesizes the androgenic substrate for aromatase. We used Northern blots, reverse transcription-polymerase chain reaction, and in situ hybridization to show that CYP17 is transcribed in developing and adult brains. CYP17 is transcribed at developmental stages and in brain areas potentially important to aspects of the developing song system, although no sex difference was detected in mRNA levels. Our results support the hypothesis that neurosteroids may act to influence brain organization and function in the zebra finch. (C) 2003 Wiley-Liss, Inc.