PYY组织表达及对翘嘴鳜的摄食调控

Tissue expression and food intake attenuation effect of peptide YY in Chinese perch (Siniperca chuatsi)

以肉食性鱼类翘嘴鳜(Siniperca chuatsi)为研究对象,对其肽YY(peptide YY,PYY)基因进行鉴定和分析,并通过中枢注射人工合成的鳜PYY多肽,研究PYY对翘嘴鳜摄食量的影响。氨基酸序列多重比对结果发现,sc-PYY与各个物种的氨基酸序列高度保守,鱼类中与狼鲈(Dicentrarchus labrax)、红鳍东方鲀(Takifugu rubripes)一致性较高;实时荧光定量PCR检测sc-PYY mRNA表达的组织分布,结果显示,sc-PYY mRNA在脑中表达量最高,在肠道、肌肉、眼睛中亦有较高的表达;翘嘴鳜中枢注射PYY后,摄食量在4 h相比于对照组(PBS)显著性下降。这表明PYY可能在减少鳜的食物摄入量中发挥着重要的作用。

As the widely commercial Chinese perch species in China,the unique feeding habits and feeding regulation mechanism of Chinese perch have always been the focus of many scientific researchers.Taking Siniperca chuatsi,a carnivorous fish,as the research object,the peptide YY(PYY)gene was analyzed and identified,and the effect of PYY polypeptide on feeding of Chinese perch was studied by intracerebroventricular(icv)administration.The results showed that the full length cDNA of Chinese perch PYY(sc-PYY)encodes a precursor protein that consists of a putative 28-amino acid signalpeptide,a 36-amino acid mature peptide,an amidation-proteolytic site,and a 30-amino acid carboxy-terminalextension.The sc-PYY gene is comprised of 4 exons interspaced by 3 introns.Amino acid alignment and gene structure comparison indicated that the amino acid sequences of PYY are highly conserved.Among the fishes studied,the consistency of sc-PYY with that of seabass and Japanese pufferfish was higher.Tissue distribution and postprandial changes of the sc-PYY mRNA expression were evaluated by real-time PCR,which showed that the sc-PYY mRNA had the highest expression in the brain,followed by high expression in the intestinal tract,muscles and eyes.The PYY icv results showed that after icv treatment,the food intake of PYY injection group decreased significantly at 4 h compared with control group(PBS).This indicated that PYY might play an important role in the regulation of food intake of Chinese perch.