Comparison of gene expression pattern between Wild-type and Hypb knockout embryo yolk sacs

This study aimed at exploring the physiological function of mammalian HYPB by means of knockout mouse model. Homogenous disruption of mouse Hypb gene leads to embryonic lethality at E10.5-E11.5. Severe vascular defects were observed in the Hypb-/- embryos, yolk sac and placenta.In the mutant embryo and yolk sac, disorganized and abnormally dilated capillaries cannot be remodeled into large blood vessels or intricate networks. Thus, our results suggest that the mammalian HYPB HMT plays an important role in embryonic vascularization. Keywords: knockout, mouse embryo development, angiogenesis, yolk sac, E9.0, E10.5 To systematically examine and compare gene expression patterns between Hypb+/+ and Hypb-/- embryos at the global genome-level, we use the Affymetrix GeneChip® mouse genome 430 2.0 arrays. We choose to use E9.0 and E10.5 yolk sacs for analysis because at E9.0 this early stage Hypb-/- embryos did not show severe visible mutant phenotype, and at E10.5 this antemortem stage Hypb-/- embryos show mang lethal mutant phenotypes. For comparison, four independently derived yolk sacs were pooled for each genotype of the two development stages, and three biological repeats were performed.