Liu Xiao-Hong, Xie Bi-Wen, Wang Zhi-Jian, Zhang Yao-Guang
Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Southwest University School of Life Sciences, Chongqing, 400715, China.
Conservation and Utilization of Fishes Resources in the Upper Reaches of the Yangtze River Key Laboratory of Sichuan Province, Neijiang Normal University, School of Life Science, Neijiang, 641000, China.
Fish Physiol Biochem. 2018 Jun;44(3):983-995. doi: 10.1007/s10695-018-0487-z. Epub 2018 Mar 17.
Using reverse transcription-polymerase chain reaction (RT-PCR) and RACE (rapid amplification of cDNA ends), somatolactin-α (rmSLα) and -β (rmSLβ) were identified from the pituitary gland of rare minnows (Gobiocypris rarus). The full-length cDNAs of these two genes were 1288 and 801 bp, encoding prepeptides of 250 and 228 amino acids residues, respectively. rmSLβ can be detected in the brain (including the pituitary), ovary, testis, and gill, while rmSLα was mainly expressed in the brain. On the other hand, rmSLα was expressed in all the fetal developmental stages; however, rmSLβ can just be detected in the stages since from 14 h post-fertilization (hpf). After exposure to acute waterborne cadmium (Cd), rmSLα was distinctly upregulated in juvenile rare minnows at all detected time points, from 24 to 96 h and 10 days, while rmSLβ was significantly altered only in 96 h or 10-day treatment groups. As for adults, acute Cd exposure caused alterations of both rmSLα and rmSLβ in the brain (containing the pituitary) at the 24 h; subchronic waterborne Cd treatment led to upregulation of rmSLα, while decrease of mSLβ in the brain. Alteration of rmSL transcripts following waterborne Cd exposure further confirmed the endocrine disruption of this heavy metal. Besides, exposure to as low as 5 μg/L Cd caused alteration of rmSLα, which suggested that rmSLα might be a potential biomarker for risk assessment of aquatic Cd.
利用逆转录聚合酶链反应（RT-PCR）和cDNA末端快速扩增（RACE）技术，从小麦穗鱼（Gobiocypris rarus）的垂体中鉴定出了生长抑素-α（rmSLα）和生长抑素-β（rmSLβ）。这两个基因的全长cDNA分别为1288和801 bp，分别编码含250和228个氨基酸残基的前肽。rmSLβ可在脑（包括垂体）、卵巢、睾丸和鳃中检测到，而rmSLα主要在脑中表达。另一方面，rmSLα在所有胎儿发育阶段均有表达；然而，rmSLβ仅在受精后14小时（hpf）及以后的阶段才能检测到。暴露于急性水体镉（Cd）后，在所有检测时间点（24至96小时和10天），幼年麦穗鱼中的rmSLα均明显上调，而rmSLβ仅在96小时或10天处理组中有显著变化。对于成年鱼，急性Cd暴露在24小时时导致脑（含垂体）中rmSLα和rmSLβ均发生变化；亚慢性水体Cd处理导致脑内rmSLα上调，而rmSLβ下降。水体Cd暴露后rmSL转录本的变化进一步证实了这种重金属的内分泌干扰作用。此外，暴露于低至5μg/L的Cd也会导致rmSLα发生变化，这表明rmSLα可能是水生Cd风险评估的潜在生物标志物。
