Cloning and expression analysis of HDAC1 gene related to growth of Litopenaeus vannamei cultured in freshwater

【Objective】To analyze the expression of histone deacetylase 1 gene（HDAC1）in shrimp families with different freshwater growth characteristics，and to clarify the function of HDAC1 gene related to growth of Litopenaeus vannamei cultured in freshwater，so as to provide a reference for revealing the molecular mechanism of growth regulation of L. vannamei.【Method】The cDNA sequence of HDAC1 gene of L. vannamei was cloned by RACE，and bioinformatics analysis was carried out by using online software such as DNAMAN，ProtParam，Protscale and PSORT. The tissue expression characteristics of HDAC1 gene of L. vannamei were detected by real-time fluorescent quantitative PCR. Four families of L. vannamei were cultured in fresh water at 1‰ salinity. After 70 days of culture，the survival rate（RS），daily gain rate，daily gain rate of body length，specific growth rate（SGR）and feed conversion rate（FCR）of L. vannamei were counted，and the expression of HDAC1 gene in the intestine of L. vannamei was detected by real-time fluorescent quantitative PCR.【Result】The full length of HDAC1 gene cDNA of L. vannamei was 3230 bp，including 67 bp 5'-UTR， 1711 bp 3'-UTR and 1452 bp open reading frame（ORF），encoding 483 amino acids in total. The total length of HDAC1 gene DNA was 4692 bp，containing eight exons and seven introns. The HDAC1 gene of L. vannamei encoded a protein with a molecular weight of 54640.22 Da and a theoretical isoelectric point of 5.59，and it was a stable hydrophilic protein with a histone deacetylase 1 domain with no transmembrane structure. The similarity of HDAC1 amino acid sequence between L. vannamei and Penaeus monodon was the highest，up to 99.79%. HDAC1 gene was expressed in all tissues of L. vannamei，and the relative expression in intestine was significantly higher than that in other tissues（P<0.05）. Among the four pedigree populations，whether big shrimp or small shrimp，the relative expression of HDAC1 gene was lower in the slow-growing population，and higher in the fast-growing population.【Conclusion】HDAC1 gene is expressed in all tissues of L. vannamei，with the highest relative expression in the intestine，and the relative expression of HDAC1 gene is directly proportional to the growth rate of L. vannamei，so it is speculated that it is involved in the growth regulation process of L. vannamei.