Immunocytochemical identification of GtH1 and GtH2 cells during the temperature-sensitive period for sex determination in pejerrey, Odontesthes bonariensis
Immunocytochemical identification of GtH1 and GtH2 cells during the temperature-sensitive period for sex determination in pejerrey, Odontesthes bonariensis
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DOI：
10.1006/gcen.2001.7687
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发表时间：
2001-10-01
影响因子：
2.7
通讯作者：
Somoza, GM
中科院分区：
文献类型：
--
作者：
Miranda, LA;Strüssmann, CA;Somoza, GM
用抗鲑鱼β-GtH_1和β-GtH_2抗血清，用免疫细胞化学方法研究了白花鱼促性腺激素1(GtH_1)和促性腺激素2(GtH_2)细胞的个体发育及其与性腺分化的可能联系。在成人中，GtH1细胞位于神经垂体附近的远侧部(PPD)，而GtH2细胞位于GtH1细胞周围、PPD外层和中间部。在幼虫中也观察到了基本相同的分布。在PeJerrey中，表型性别由性别决定的关键时期(温度依赖的性别决定，TSD)的温度决定。雌性比例从13-19度的100%逐渐变化到29度的0%，TSD的临界期估计分别为孵化后3-5周、2-4周和1-4周。因此，从孵化到第11周，在17、24和29度饲养的幼虫中，每周检测一次这两种GtH的表达。17度、24度和29度的女性比例分别为100%、78%和0%。组织学上卵巢分化在17度和24度出现在7周和4周，而睾丸分化在7周和4周出现在24度和29度。GtH1细胞最早出现于第3周29度，第4周17度和24度。这些细胞的数量在4周前增加，然后减少，6周后在所有温度范围内消失。GtH2细胞出现在第2周24度和29度，第3周17度。GtH2细胞数在29度时增加到第3周，在17度和24度时增加到第4周，然后暂时减少，之后又增加。这些结果强烈表明GtH1和GtH2是由不同的细胞表达的。GtH1和GtH2细胞在所有温度下都出现在组织性腺分化之前，同时GtH1和GtH2细胞数量在温度敏感期达到峰值，这表明GtHs与性别分化或TSD有关。(C)2001年学术出版社。
The ontogeny of gonadotropin 1 (GtH1) and 2 (GtH2) cells and its possible link to gonadal sex differentiation were studied in pejerrey, Odontesthes bonariensis, by immunocytochemistry using anti-chum salmon beta -GtH1 and beta -GtH2 antisera. In adults, GtH1 cells were found in the proximalis pars distalls (PPD) close to the neurohypophysis, whereas GtH2 cells were identified surrounding GtH1 cells, at the external layer of the PPD and in the pars intermedia. Essentially the same distribution was observed in larvae. In pejerrey, the phenotypic sex is governed by the temperature during the critical period of sex determination (temperature-dependent sex determination, TSD). Female proportions vary gradually from 100% at 13-19 degrees to 0% at 29 degrees, and the critical time of TSD has been estimated to be 3-5, 2-4, and 1-4 weeks after hatching at 17, 19, and 27 degrees, respectively. Thus, the expression of both GtHs was examined weekly in larvae reared from hatching to week 11, at 17, 24, and 29 degrees. The proportion of females at 17, 24, and 29 degrees was, 100%, 78% and 0%, respectively. Histological ovarian differentiation was noticed at 7 and 4 weeks at 17 and 24 degrees, whereas testicular differentiation occurred at 7 and 4 weeks at 24 and 29 degrees. GtH1 cells were first observed at week 3 at 29 degrees and at week 4 at 17 and 24 degrees. These cells increased in number until week 4 and then decreased, disappearing after week 6 at all temperature regimes. GtH2 cells appeared at week 2 at 24 and 29 degrees and at week 3 at 17 degrees. GtH2 cell number increased until week 3 at 29 degrees and until week 4 at 17 and 24 degrees and then temporarily decreased, thereafter increasing again. These results strongly suggest that GtH1 and GtH2 are expressed by different cells. The fact that GtH1 and GtH2 cells appear just before histological gonadal differentiation at all temperatures, together with the peak of GtH1 and GtH2 cell number during the temperature-sensitive period, suggests that GtHs are related to sex differentiation or TSD in O. bonariensis. (C) 2001 Academic Press.