Abstract: cDNA sequence of Leptin A（LepA）gene，which plays key roles in food intake，growth，reproduction，immunity and energy balance，was cloned by rapid amplification of cDNA ends（RACE）in seabass Lateolabrax maculatus exposed to acute salinity changes：seawater group（a salinity of 32），semi-seawater group（a salinity of 16）and fresh water group（a salinity of 0）.Hepatic LepA mRNA were determined by qPCR 24，48，96，144，and 192 h after salinity exposure.It was found that LepA cDNA was 643 bp in length containing a CDs of 161 amino acid residules，a signal peptide，and four α-helices（A，B，C and D）.Deduced amino acid sequencing showed that the sequence of LepA showed low identity to Leps from other fishes，with conservative three-dimensional structure modeling.LepA was primarily expressed in liver，and a little expression of the LepA was observed in brain. There was significantly less expression of LepA mRNA in seabass in semi-seawater group（accounting for 33.38% of seawater group expression）and fresh water group（accounting for 26.86%of seawater group expression）than that in seawater group at 48 h（P＜0.05），without significant difference between the semi-seawater group and fresh water group（P＞0.05）.LepA mRNA expression was induced to be decreased in all groups after 96 h.The findings suggested that expression of LepA mRNA in seabass be decreased under acute low salinity regulation.
2016, Vol. 31 
