Isolation Of Fatty Acid Binding Protein Genes And The Correlation Between JLFABP2A Polymorphisms And Growth Trait In Cyprinus Carpio Var. Jian

Fatty acid binding proteins (FABPs) were cytosolic proteins that bind long-chain fatty acids, these proteins were expressed in invertebrates and vertebrates tissues, with distinct expression patterns for the individual FABPs. They were involved in the uptake and transport of fatty acids to different cellular fates and participate in the regulation of gene expression and cell growth. We had isolated six FABP genes from Cyprinus carpio var. jian, belonging to FABP1, FABP2, FABP7, respectively. And we denoted them as jlFABPlb1、 jlFABPlb2, jlFABP2a, jiFABP2b, jlFABP7al、jlFABP7a2. The amino acids sequences in common carp exhibit81-90%similarity with their counterparts in zebrafish. Phylogenetic tree of FABPs displayed the FABPs family likely arose through duplication and diversification of an ancestral iLBP gene and12types FABPs in the phylogenetic tree were clustered into three clusters, which consistent with their classification in the iLBPs family. All FABPs amino acid sequence was divided into three clusters, FABP3and FABP7grouped into one clade with high confidence level, then they merged with FABP4、 FABP5、FABP8、FABP9、FABP12composing the fist cluster. FABP1、FABP6、FABP10composed the second cluster and FABP2as the third one. It’s shown that the genetic distance of FABPs was consistent with their classification status in the class level from the phylogenetic tree, but it can’t identify the species evolution level in the order and family level. Real time RT-PCR was performed in determination FABP2s, FABP7s and FABP3s expression levels in brain, liver, intestine, muscle, kidney, hear and gonad. Results showed that FABP2s were mainly expressed in intestine with significantly higher than that in other tissues, and the expression of jlFABP2a was significantly higher than jlFABP2b in intestine. jlFABP3a was mainly expressed in gonads, liver, brain and muscle, and its expression in testis was significantly higher than other tissues studied. jlFABP3b was mainly expressed in heart, muscle, liver, and its expression was higher than jlFABP3a in those tissues. The expression of jlFABP7s in testis was significantly higher than that in ovary. The expression of JlFABP7a2in brain and liver was significantly higher than jlFABP7al, and jlFABP7al was hardly expressed in the liver.Twelve and four SNP loci were confirmed at jlFABP2a and2b introns through comparingsequences from8individuals, respectively. Four SNP loci including I1-A15G、 I1-A99G、I2-C487T and I3-A27T at2a were detected using PCR-RFLP. The SNP genotypes and individual weight gain correlation indicated that four SNPs were very significantly or significantly associated with adult weight gain in selection population of Cyprinus carpio var. jian. Diplotype analysis displayed that individuals with AGGGCCXX or AGGGXXAT grewl5%faster than other individuals. The number of the individuals with these two genotypes only has a percentage of9%in total selection populations, indicating the large selection space and usability in breeding plan. SNP sites and growth index correlation analysis showed that these four SNPs were significantly or very significantly associated with growth character such as body length and height. I1_A15G had a significant correlation with body length and height, tail length and height; I1_A99G had a significant correlation with tail length providing a usefull reference to shape breeding program.