Molecular Characterization And Evolutional Analysis Of Lipoprotein Lipase (LPL) And Hepatic Lipase (HL) Gene In Fishes

In order to study the structural and functional relationship of vertebrate lipoprotein lipase(LPL) and hepatic lipase (HL) genes as well as their molecular evolutional relationship, wecloned partial liver LPL cDNA sequences of amphioxus, Chinese sturgeon, silver carp, bigheadcarp, grass carp, tilapia and Chinese perch, and partial liver HL cDNA sequences of Chinesesturgeon, silver carp, bighead carp, grass carp, tilapia and Chinese perch as well as thefull-length cDNA sequences of Chinese perch LPL and HL gene by RACE. A phylogenetic treewas constructed by neighbor-joining method with the Mega 3.1 software. After isolatingChinese perch genomic DNA and constructing the library, we cloned 5'-flanking region ofChinese perch LPL and HL gene. Only LPL cDNA sequences but no HL gene was cloned inprimordial cephalochordate amphioxus; however, both LPL and HL were obtained in all theteleost and non-teleost bony fishes studied, such as Chinese sturgeon, silver carp, bighead carp,grass carp, tilapia and Chinese perch, suggesting that HL gene might evolve from LPL aftergene duplication. Usingβ-actin as control, we analysed the LPL and HL gene tissue expressionpattern of Chinese perch by RT-PCR. The mRNA expression of Chinese perch LPL gene wasdetected in all the examined tissues: highest in adipose tissue, followed by liver, brain, intestine,muscle, and lowest in spleen. But the Chinese perch HL gene was found to be exclusivelyexpressed only in liver.