Genetic Dissection of PI3K Pathway

The mutant alleles used here have been described previously: Pten^flox (Trotman et al., 2003 (link)), Pdk1^flox (MGI designation: Pdpk1) (Lawlor et al., 2002 (link)), R26-Pik3ca^H1047R (Jackson Laboratories, Bar Harvor, ME. Stock #016977). The epiblast specific-expressing CRE line is Sox2-CRE (Hayashi et al., 2002 (link)). The Wnt-reporter line used was TOPGAL (DasGupta and Fuchs 1999 ). The genotype of the Pten ΔEpi (epiblast-deleted) embryos is Sox2-Cre/+; Pten^flox/Pten^null. The genotype of the Pdpk1 ΔEpi embryos is Sox2-Cre/+; Pdpk1^flox/Pdpk1^null. The genotype of the Pten Pdpk1 ΔEpi double mutants is Sox2-Cre/+; Pten^flox/Pten^null; Pdpk1^flox/Pdpk1^null. We generated the Pten and Pdpk1 deleted (null) alleles by crossing conditional mice with Sox2-Cre, taking advantage of Sox2 activity in the female germ line. The X-linked GFP transgene was a gift from Anna-Katerina Hadjantonakis (Hadjantonakis et al., 2001 (link)). Pten mutants were congenic in CD1, and all other lines, except R26-Pik3ca^H1047R (FVB), were backcrossed to CD1 for at least four generations before analysis. For timed pregnancies, noon on the day of the vaginal plug was E0.5.