EFFECT OF DIFFERENT FASTING STAGES ON GHRELIN EXPRESSION IN BLACK SEABREAM ACANTHOPAGRUS SCHLEGELI
不同饥饿时段对黑鲷(Acanthopagrus schlegeli)ghrelin 基因表达的影响

To analyze the roles of ghrelin in food intake of black seabream in detail, real-time quantitative PCR was adopted to examine the ghrelin gene expression. Total RNA was extracted from black seabream stomach tissue and the fragments of target gene were amplified by RT-PCR with special primers. PCR product was cloned via pGEM-T Easy vector and plasmid extracted. The recombinant plasmid was identified by PCR amplification and restriction enzyme analysis. Real time quantitative PCR was also applied to detect the ghrelin expression in stomach, intestine and hypothalamus tissues during different fasting stage. The results show that the expression of ghrelin increased in stomach and intestine tissue but not in hypothalamus tissue during a short period of fasting (2 days) (P<0.05) . However, during a long period of fasting (7 days), the expression decreased in stomach and intestine tissue, but still higher than that of the control (P<0.05), which was increased in hypothalamus tissue (P<0.05). Besides, the expression of ghrelin in different tissues at the same stage was different (P<0.05). The expression of ghrelin in different tissues did change in different fasting stages, suggesting that ghrelin is involved in the regulation of food intake in black seabream.