cDNA cloning and expression of vitamin-K Epoxide Reductase (VKOR) gene from orange spotted grouper <i>Epinephelus coioides</i><i><span style="font-family:"Book Antiqua"; mso-bidi-font-family:Arial" lang="EN-US"></span></i>

Abstract

The cDNA sequence encoding Vitamin-K Epoxide Reductase (VKOR) was constructed from hypothalamus and pituitary cDNA libraries of Orange spotted Grouper <i>Epinephelus coioides</i>. VKOR gene contains 610 nucleotides including the open reading frame (ORF) of length 399 bp. ORF was started with ATG codon at the position of 199 and terminated with a stop codon TAA of 585. ORF sequence had 128 amino acids and the predicted protein molecular weight is approximately 14.08 kDa (GenBank: FJ939281.1). Expression of VKOR gene in different tissues was further examined using one-step RT-PCR. RT PCR result revealed that, VKOR mRNA expression was detected only in liver, kidney, hypothalamus and pituitary. VKOR gene sequence of <i>E. coioides</i> aligned with related sequences by multiple sequence alignment by clustal X and phylogenetic tree was generated by Neighbor Joining method using Genious v 5.4. <i>E. coioides</i> VKOR had the highest identity and homology with the puffer fish, <i>Tetraodon nigroviridis, Takifugu rubripes</i> and Zebra fish <i>Danio rerio</i>. Based on the VKOR expression in the kidney, liver hypothalamus and pituitary of the seven year’s old (sex reversal stage) <i>E. coioides</i>, it may be involved in sex reverse.