Development of velvet coat (Ve/Ve), another early lethal mutation in the house mouse

A new semidominant mutation in the house mouse, velvet coat (Ve), is described. Ve homozygotes, recognizable on day 5 of gestation by their deficiency of ectodermal cells, never produce mesoderm and are resorbed by days 9-10. Primary Ve action may occur during the formation of the blastocyst or during determination and differentiation of the inner cell mass, or both. Accordingly, Ve/Ve embryos may provide a useful model for investigating primary gene action during blastocyst formation and subsequent differentiation.