Raven P A, Uh M, Sakhrani D, Beckman B R, Cooper K, Pinter J, Leder E H, Silverstein J, Devlin R H
Department of Fisheries & Oceans, Centre for Aquaculture & Environmental Research, West Vancouver, BC, Canada.
Gen Comp Endocrinol. 2008 Oct;159(1):26-37. doi: 10.1016/j.ygcen.2008.07.011. Epub 2008 Aug 5.
Non-transgenic (wild-type) coho salmon (Oncorhynchus kisutch), growth hormone (GH) transgenic salmon (with highly elevated growth rates), and GH transgenic salmon pair fed a non-transgenic ration level (and thus growing at the non-transgenic rate) were examined for plasma hormone concentrations, and liver, muscle, hypothalamus, telencephalon, and pituitary mRNA levels. GH transgenic salmon exhibited increased plasma GH levels, and enhanced liver, muscle and hypothalamic GH mRNA levels. Insulin-like growth factor-I (IGF-I) in plasma, and growth hormone receptor (GHR) and IGF-I mRNA levels in liver and muscle, were higher in fully fed transgenic than non-transgenic fish. GHR mRNA levels in transgenic fish were unaffected by ration-restriction, whereas plasma GH was increased and plasma IGF-I and liver IGF-I mRNA were decreased to wild-type levels. These data reveal that strong nutritional modulation of IGF-I production remains even in the presence of constitutive ectopic GH expression in these transgenic fish. Liver GHR membrane protein levels were not different from controls, whereas, in muscle, GHR levels were elevated approximately 5-fold in transgenic fish. Paracrine stimulation of IGF-I by ectopic GH production in non-pituitary tissues is suggested by increased basal cartilage sulphation observed in the transgenic salmon. Levels of mRNA for growth hormone-releasing hormone (GHRH) and cholecystokinin (CCK) did not differ between groups. Despite its role in appetite stimulation, neuropeptide Y (NPY) mRNA was not found to be elevated in transgenic groups.
对非转基因（野生型）银大麻哈鱼（Oncorhynchus kisutch）、生长激素（GH）转基因大麻哈鱼（生长速率大幅提高）以及成对投喂非转基因日粮水平（因而以非转基因速率生长）的GH转基因大麻哈鱼进行了血浆激素浓度以及肝脏、肌肉、下丘脑、端脑和垂体mRNA水平的检测。GH转基因大麻哈鱼的血浆GH水平升高，肝脏、肌肉和下丘脑的GH mRNA水平增强。与非转基因鱼相比，完全投喂的转基因鱼血浆中的胰岛素样生长因子-I（IGF-I）以及肝脏和肌肉中的生长激素受体（GHR）和IGF-I mRNA水平更高。转基因鱼的GHR mRNA水平不受日粮限制的影响，而血浆GH升高，血浆IGF-I和肝脏IGF-I mRNA降至野生型水平。这些数据表明，即使在这些转基因鱼中存在组成型异位GH表达的情况下，IGF-I产生的强大营养调节作用仍然存在。肝脏GHR膜蛋白水平与对照组无差异，而在肌肉中，转基因鱼的GHR水平升高了约5倍。转基因大麻哈鱼中观察到的基础软骨硫酸化增加表明，非垂体组织中异位GH产生对IGF-I有旁分泌刺激作用。生长激素释放激素（GHRH）和胆囊收缩素（CCK）的mRNA水平在各组之间没有差异。尽管神经肽Y（NPY）在刺激食欲方面发挥作用，但在转基因组中未发现其mRNA升高。
