Identification and characterization of the Oct4 extended transcriptional regulatory region in Guanzhong dairy goat.

The octamer-binding transcription factor 4 gene (Oct4) plays a critical role in maintaining pluripotency during early mammalian embryonic development and self-renewal of embryonic stem (ES) cells. In this study, we cloned the Oct4 cDNA and 2.8-kb regulatory region upstream of the start codon in Guanzhong dairy goat ( Capra hircus ). The comparative sequence analysis of Oct4 cDNA showed that it was highly conserved among six mammalian species. The goat Oct4 5' regulatory regions were homologous to the corresponding regions of Oct4 in other species and were functional in directing the expression of luciferase in mouse P19 embryonic carcinoma cells and mouse J1 ES cells. Furthermore, the methylation levels in the goat Oct4 minimal promoter and proximal enhancer in the fetal genital ridge were lower than those in the heart. Additionally, two processed pseudogenes that shared high homology with goat Oct4 cDNA were identified and characterized.