Cloning and characterization of p8 homolog cDNA in the Atlantic halibut (Hippoglossus hippoglossus).

The p8 gene encodes a transcription factor known to modulate cell growth, division, and apoptosis and influences gene expression. In this study, an Atlantic halibut (Hippoglossus hippoglossus) homolog of the p8 gene was cloned, sequenced, and characterized. The full-length p8 cDNA consists of 601 bp and encodes 76 amino acids with a molecular mass of 9 kD. The bHLH region is well conserved between Atlantic halibut and other animals. Analysis by RT-PCR showed that the p8 transcript is constitutively expressed in 9 of the 12 tissues tested: pancreas, intestine, stomach, gill, head kidney, heart, liver, ovary, and spleen. A predicted microRNA target site was found in the 3'UTR of Atlantic halibut p8 mRNA. We speculate that the target site may pair to microRNA molecules because the target site resides in a big loop, a space large enough for the binding of microRNA molecules.