Cloning And Expression Analysis Of The Follistatin Gene In Larimichthys Crocea

Follistatin(FST) belongs to transforming growth factor β superfamily, it has awide range of biological functions, relating to reproduction, growth and developmentand so on. RT-PCR, RACE and conventional PCR techniques were used to clone FSTgene from the total RNA of Larimichthys crocea kidney in this study, conventionalPCR technique was used to clone the intron of FST from genomic DNA. The lengthof follistatin gene sequence was3195bp,containing a96bp5’ untranslatedregion(UTR), exonⅠ91bp,intronⅠ1166bp,exon Ⅱ198bp,intronⅡ196bp, exonⅢ219bp, intron Ⅲ131bp, exon Ⅳ225bp, intron Ⅳ623bp, exon Ⅴ239bp anda47bp3’-UTR. The complete open reading frame of follistatin was972bp, encoding apeptide of323amino acid residues, signal peptide was made up of the front31aminoacids, mature peptide was made up of the later292amino acids.The rusults of Blastsuggested that the nucleotide and protein sequence of follistatin between Larimichthyscrocea and Sparus aurata were highest conserved,96%and99%, respectively.FST gene is expressed in various tissues of Larimichthys crocea, includingbrain，eye，gill，heart,intestine，kidney, liver, skeletal muscle, spleen, in which the gilltissue is highest, and the spleen the lowest.To detected the expression of FST gene of Larimichthys crocea in the differenttemperature, setting19℃,25℃and30℃as variable group. When19℃, FST geneexpression hinger in brain and gill; When25℃, FST gene expression hingest in eye;When30℃, FST gene expression hinger in muscle.The results suggest that FSTexpression in eye and muscle tissues greatly changed(P<0.05). Under thecircumstances of Pseudomonnas putida （107cfu/mL lunbar injection of0.4mL）infection, FST expression in spleen and liver significantly increased, whereas FSTexpression in gill and heart tissues greatly decreased(P <0.05). The results suggestedthat FST may play an important role in fish immune process.