Hormonal induction of spermiation,courting behavior and spawning in the southern bell frog,Litoria raniformis

We trialled the efficacy of various exogenous hormones to induce spermiation, courtship behavior, and spawning in the “endangered” southern bell frog, Litoria raniformis. Intralymphatic administration of Lucrin^®, a synthetic nonapeptide luteinizing hormone releasing hormone (LHRH), was used successfully to induce courting behaviors and ejaculation of spermatozoa in males. Various hormones, including Lucrin^®, another synthetic LHRH analog ([des‐Gly¹⁰, D‐Ala⁶]‐LHRH), human chorionic gonadotropin, progesterone, and a dopamine receptor antagonist failed to promote oviposition and spawning in females. This and earlier studies indicate that in the efficacy of hormonal induction in amphibians varies between taxa, hormones, and genders. The lack of response in females may limit the use of reproduction technology in the southern bell frog and closely related species of Australian bell frogs. Zoo Biol 29:774–782, 2010. © 2010 Wiley‐Liss, Inc.     

多马胺能药物对鲇鱼促性腺激素（GtH）分泌活动的影响

以珠江流域鲇鱼（silurus asotus)为实验材料,研究了多巴胺（DA）能药物（DA及其D－2型受体拮抗物 ,DOM）对鲇鱼促性腺激素（GtH)释放的影响,结果表明,在性腺发育的各个时期,单独注射DOM（5ug/g)均不能显著提高鲇鱼血液基础GtH水平,当DOM与LHRH－A联合注射时能显著增强LHRH－A刺激GtH释放的作用;DA只能抑制GnRH诱导的GtH释放,对基础GtH释放无抑制作用,这种生殖内分泌调节方式与鲇形目的革胡子鲇（Clarias gariepinus)和大鳍Hu（Mystus macropterus)相似,而与鲤形目的鲁科（Cyrpindiae)鱼类不同。     

鳗鲡繁殖生物学研究Ⅳ．人工催熟过程中下海鳗鲡的GtH分泌活动、性腺发育状况和脑垂体GtH细胞的超显微结构

雌二醇通过正反馈作用能促进脑垂体促性腺激素(GtH)细胞的合成活动,使脑垂体GtH水平显著升高。促黄体素释放激素的类似物(LHRH-A)和利血平(reserpine,RES)能促进脑垂体GtH细胞的分泌活动,使血液中GtH含量显著升高。鲤垂体、人体绒毛膜促性腺激素(HCG)和LHRH—A三种激素混合进行多次注射能诱导雌雄鳗鲡性腺发育成熟,其催熟效果明显优于它们的分别单独多次注射或者鲤鱼脑垂体和HCG的多次注射,表明外源的和内源的促性腺激素对于诱导鳗鲡性腺发育成熟都是重要的。鳗鲡脑垂体GtH细胞超显微结构的观察证实它们在激素诱导性腺发育成熟过程中处于活跃的合成与分泌状态。     

Pheromone of male blue gourami and its effect on vitellogcnesis, steroidogenesis and gonadotropin cells in pituitary of the female

Female Trichogaster trichopterus were exposed to aquarium water in which males had built nests. Gonadotropin cells in the pituitary gland, and exovitellogenesis and steroidogenesis in the ovary were studied. In females in which the percentage of oocytes in vitellogenesis (%V) was low initially, it rose significantly in comparison with an unexposed control group. In females in which the %V was higher initially, it increased further, and in addition a significant percentage of oocytes reached maturation. Thin layer chromatography, using the precursors ³H-pregnenolone and ¹⁴progesterone, revealed high yields of the steroids 17β-estradiol (E₂), 17α,20β-dihydroxy-4-pregnen-3-one (17,20-P), 5β-pregane,3α,17α,20β-triol (5β-P-triol) and 11-ketotestosterone (11KT) in both experimental groups. Significant differences were found in E₂, 17,20-P and 5β-P-triol between the test and control groups. The immunoresponse of GtH-producing cells in the pituitary of the females maintained in nest water was lower than in the control group, suggesting that the GtH was secreted from the cells, which would explain the vitellogenic and steroidogenic changes found in the ovary.     

细胞外Ca^＋＋对脉冲式和持续性鲑GnRH类似物刺激鲤GtH分泌的影响

２ｍｉｎ脉冲式１０ｎｍｏｌ鲑ＧｎＲＨ高效类似物ｓＧｎＲＨ－Ａ（Ａｒｇ＾６Ｔｒｐ＾７Ｌｅｕ＾８Ｐｒｏ＾９ＮＥｔ－ＬＨＲＨ）刺激导致离体灌流培育的鲤脑垂体迅速产生显著的ＧｔＨ分泌峰,ＧｔＨ分泌在刺激后３０ｍｉｎ内恢复到基础水平。４ｈ１０ｎｍｏｌ／Ｌ ｓＧｎＲＨ－Ａ持续性刺激导致灌流培育的鲤脑垂体ＧｔＨ分泌出现脱敏反应,整个过程包括刺激后迅速的ＧｔＨ分泌峰相和随后持续低水平的ＧｔＨ分泌相。无Ｃａ＾＋＋的     

鲤鱼发育早期HPG轴和GH/IGF轴相关因子的转录起始分析

采用RT-PCR的方法,以不同发育时期的鲤鱼胚胎和幼鱼为材料,研究了与鱼类生殖相关的HPG轴以及与生长相关的GH/IGF轴中GnRH、GtH以及GH、GHR和IGF重要信号分子的转录起始特征.结果显示,sGnRH、cGnRH、GtH-Ⅰβ卢亚基和GHR于鲤鱼胚胎受精后20h开始转录,IGF-1于受精后23h开始转录,GtH-Ⅱβ亚基于受精后26h开始转录,GtH α亚基于受精后46h开始转录,GH于1dph(孵出后第1天)开始转录.其中,GHR和IGF-1均早于GH开始转录,GtH α亚基和β亚基的转录起始时间不同步.研究结果为揭示鲤鱼生殖与生长间的调控机制积累了重要的科学依据.