Pik3cd^tm1Tnr

Exons 1 through 9, encoding the first 490 amino acids, were deleted by homologous recombination of floxed selection genes followed by cre mediated excision in male germ cells. Targeting was done in PC3 ES cells which are homozygous for a protamine-cre transgene, Tg(Prm-cre)70Og, which expresses Cre recombinase only in halpoid spermatids. Normal protein was undetected by Western blot analysis of thymocytes obtained from homozygous mutant mice. (J:79133)