Cloning and SNP locus screening of CCT6 gene in Litopenaeus vannamei

【Objective】Cloned CCT6 gene of Litopenaeus vannamei and screened SNP loci related to growth to provide reference for screening of fast-growing L. vannamei molecular marker assisted breeding. 【Method】The cDNA and DNA sequences of the CCT6 gene in L. vannamei were obtained through gene cloning,and analyzed them using online bioinformatics softwares such as ExPASy,InterPro,TMHMM,SOPMA and SWISS-MODEL. Real time fluorescence quantitative PCR technology was used to determine the expression of the CCT6 gene in different tissues and two groups of L. vannamei with different growth rates. Using direct sequencing method to screen the SNP loci of CCT6 gene and analyze the correlation between the SNP loci and the growth traits of L. vannamei. 【Result】The total length of CCT6 gene cDNA sequence of L. vannamei was 1835 bp,the 5' and 3' non coding region(UTR) were 55 and 193 bp,the open reading frame(ORF) was 1587 bp,encoding a total of 531 amino acids residues. The length of the DNA sequence was 15873 bp,with 11 exons and 10 introns. The CCT6 gene was expressed in the eye stalks,gills,stomach,hepatopancreas,heart,intestine and muscle tissues of L. vannamei,and the expression level in the intestinal tissue was significantly higher than that in other tissues(P<0.05, the same below). The growth indexes such as final body weight and final body length of A group were significantly higher than that of B group, and the relative expression of CCT6 gene in the intestinal tissue of fast growing L. vannamei A group was significantly higher than that in B group. Six SNP loci were screened from the DNA sequence of CCT6 gene,two SNP loci were located in the exon of DNA sequence,and four SNP loci were located in the intron. The C14895C>T locus located in the intron region was significantly correlated with the growth traits of L. vannamei.The length and weight of L. vannamei with C14895C>T locus CC genotype were significantly higher than those of the TT genotype,and the number of CC genotypes in the A group of L. vannamei was higher than that in the B group. 【Conclusion】CCT6 gene plays an important role in the growth and development of L. vannamei, the fast growing A group tends to be a homozygous CC genotype and the C14895C>T locus can be used as a candidate marker for molecular marker-assisted breeding of the fast growing L. vannamei.