Intensive gene targeting studies in mice have revealed that prolyl hydroxylase domain proteins (PHDs) play important roles in murine embryonic development; however, the expression patterns and function of these genes during embryogenesis of other vertebrates remain largely unknown. Here we report the molecular cloning ofphd1and systematic analysis ofphd1,phd2, andphd3expression in embryos as well as adult tissues ofXenopus laevis. All threephdsare maternally provided duringXenopusearly development. The spatial expression patterns ofphdsgenes inXenopusembryos appear to define a distinct synexpression group. Frogphd2andphd3showed complementary expression in adult tissues withphd2transcription levels being high in the eye, brain, and intestine, but low in the liver, pancreas, and kidney. On the contrary, expression levels ofphd3are high in the liver, pancreas, and kidney, but low in the eye, brain, and intestine. All threephdsare highly expressed in testes, ovary, gall bladder, and spleen. Among threephds,phd3showed strongest expression in heart.
Comparative analysis of serine protease-related genes in the honey bee genome: possible involvement in embryonic development and innate immunity