CLONE AND EXPRESSION ANALYSIS OF TRANSCRIPTION COFACTOR LBH-B in GIBEL CARP

LBH (limb-bud and heart) is a novel high-conserved transcription cofactor in vertebrates involved in embryonic development and pathogenesis of some human disease. We screened the lbh-b gene that was abundantly expressed in the pituitary of gibel carp, and cloned the lbh-b (Cglbh-b) cDNA sequence of lbh gene family from gibel carp cDNA library by RACE-PCR. The full-length of Cglbh-b cDNA was 1526 bp with a 549 bp long open reading frame (ORF) coding a 182 amino acid protein. Bioinformatics analysis showed that CgLbh-b protein shared high homology (>68%) with other vertebrate LBH and is one of intrinsic disordered proteins.Cglbh-b was abundantly expressed in pituitary, telencephalon, ovary and eye of adult gibel carp. The expression of Cglbh-b in female pituitaries was 4.66 times higher than that in male pituitaries, and Cglbh-b in pituitary was up-regulated during the process of oocyte maturation. During the early embryonic development, maternal mRNA of Cglbh-b was detected in embryos from 4-cells stage to gastrula stage, and its transcripts were synthesized at bud stage. The results of whole mount in situ hybridization showed that Cglbh-b was distributed on the brain and eyes of embryos from 2 days post fertilization (dpf) to 3dpf. These results suggest that Cglbh-b may play important roles in brain and retina development, and reproductive regulation in oocyte maturation of gibel carp.