Genes affect the timing of early mouse embryo development

The rate of preimplantation mouse embryo development was found to be influenced by genes both within and outside the H-2 complex. An H-2 associated gene, called Ped, was shown to govern either fast or slow development. Analysis of congenic strains on a C57BL/10Sn background showed that fast development is associated with the b, d, q, s, and u haplotypes, whereas slow development is associated with the k and r haplotypes. Analysis of the recombinant haplotype, a suggested that the fast Ped gene maps to the D end of the H-2 complex. The study of congenic strains on a BALB/c background has shown that background genes, as well as the H-2 associated Ped gene, play a role in the control of the rate of early embryonic cleavage.