凡纳滨对虾CTSL基因与生长相关的SNP位点的特征

对3个凡纳滨对虾品系的CTSL基因进行单核苷酸多态性（single nucleotide polymorphism，SNP）筛查，发现在生长指标差异的对虾中存在特征较为显著的7个SNP位点，其中3个属于外显子上的突变，4个属于内含子上的突变．B210对虾品系体重月平均生长量约为7．58g，体长月平均生长量约为2．31cm，B310对虾品系体重月平均生长量约为3．96g，体长月平均生长量约为1．48cm，HNIT对虾品系体重月平均生长量约为3．04g，体长月平均生长量约为2．18em．从市场价值来看，B210和B310品系比HNTr品系生长相对好些．进一步的PCR产物直接测序比较分析表明在生长指标较好的对虾品系，这7个SNP位点表现为纯合子；而在生长指标较差的对虾品系，在这7个SNP位点上31．6％表现为杂合子．虽然国内外有不少关于CTSL基因SNP位点的报道，但是与生长快慢的相关分析还鲜有报道，且这些SNP位点与前人发现的位点有所不同．本研究发现的CTSL基因的SNP位点与对虾生长快慢相关，将为凡纳滨对虾生长研究提供有用信息，从而有助于为对虾选育提供可靠的分子标记．

Characters of SNP associated with the growth of CTSL gene in Litopenaeus vannamei

In this study, we screened single nucleotide polymorphism （SNP） of CTSL in 3 different families of Litopenaeus Vannamei. The results showed that there were 7 novel and significant SNPs amount 3 families, of which 3 SNPs were located in exon and 4 were located in intron. The average monthly weight growth was about 7.58 g and length growth was about 2.31 cm in B210. The average monthly weight growth was about 3.96 g and length growth was about 1.48 cm in B310. The average monthly weight growth was about 3.04 g and length growth was about 2.18 cm in HNTT. From the point of market, the growth of B210 and B310 strains are comparably better than HNTT. Further analysis by PCR product direct sequencing revealed that all these SNPs were homozygous in the families with better growth performance ,while 31.6% of them were heterozygous in the families with weak growth performance. Although the SNPs of CTSL gene have been extensively studied in the world, the analysis on the correlation between SNPs and growth is very limited and these SNPs are different from what has been found previously. The results indicate that these SNPs of CTSL gene were related to the growth speed of Litopenaeus Vannamei shrimp families. The finding could provide useful information for further study and reliable molecular markers for Litopenaeus Vartnamei breeding.