Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Anhui, People's Republic of China.
Alligator Research Center of Anhui Province, Xuancheng, People's Republic of China.
J Exp Zool A Ecol Integr Physiol. 2017 Feb;327(2-3):79-88. doi: 10.1002/jez.2072. Epub 2017 Jun 15.
The Chinese alligator (Alligator sinensis), a freshwater crocodilian endemic to China, is one of the most endangered crocodilian species; up to this date, very little is known about the endocrine regulation of its metabolic activities during different physiological states. In this study, we characterized the structure of the prepro-vasoactive intestinal peptide in Chinese alligator (prepro-caVIP) for the first time and examined its expression profiles in various tissues during the active and hibernating periods. The prepro-caVIP cDNA consists of a 221-bp 5'-untranslated region (UTR), a 606-bp complete coding region (CDS), and a 312-bp 3'-UTR, which encodes the 201-amino acid prepro-caVIP containing a 28-amino acid vasoactive intestinal peptide (VIP) and a 27-amino acid PHI (peptide histidine isoleucine). Multiple alignment analysis showed that VIP shares 100% identity with the given birds, reptiles, and African clawed frog, and 89% identity with mammals, 96% with fishes. Real-time quantitative PCR showed that the prepro-caVIP is widely expressed in all the examined tissues, and the expression level is significantly higher in small intestine, stomach, pancreas, lung, and skeletal muscle, whereas lower in heart, liver, spleen, kidney, ovary, and oviduct. During hibernation, the expression level of caVIP was significantly decreased in small intestine (P < 0.01), pancreas, and skeletal muscle (P < 0.05), whereas significantly increased in liver, spleen, and lung (P < 0.01). The wide distribution of caVIP and its differential expression changes in various tissues during hibernation implicated that it might play multiple effects in Chinese alligator and participate in the physiological adaptation of various organs in a paracrine and/or neurocrine manner.
扬子鳄（Alligator sinensis），一种原产于中国的淡水鳄，是最濒危的鳄鱼物种之一；到目前为止，人们对其在不同生理状态下代谢活动的内分泌调节知之甚少。在本研究中，我们首次对扬子鳄的前啡肽原（prepro-caVIP）结构进行了特征描述，并在活跃期和冬眠期检查了其在各种组织中的表达谱。prepro-caVIP cDNA 由 221bp 的 5'非翻译区（UTR）、606bp 的完整编码区（CDS）和 312bp 的 3'UTR 组成，编码 201 个氨基酸的 prepro-caVIP，其中含有 28 个氨基酸的血管活性肠肽（VIP）和 27 个氨基酸的 PHI（肽组氨酸异亮氨酸）。多重比对分析表明，VIP 与所给鸟类、爬行动物和非洲爪蟾完全一致，与哺乳动物的同一性为 89%，与鱼类的同一性为 96%。实时定量 PCR 显示，prepro-caVIP 在所有检查的组织中广泛表达，在小肠、胃、胰腺、肺和骨骼肌中的表达水平显著较高，而在心脏、肝脏、脾脏、肾脏、卵巢和输卵管中的表达水平较低。在冬眠期间，caVIP 的表达水平在小肠（P<0.01）、胰腺和骨骼肌（P<0.05）中显著降低，而在肝脏、脾脏和肺中显著增加（P<0.01）。caVIP 的广泛分布及其在冬眠期间在各种组织中的差异表达变化表明，它可能在扬子鳄中发挥多种作用，并以旁分泌和/或神经内分泌的方式参与各种器官的生理适应。
