FIG 1.

Gross morphology of Rb1-deficient embryos. (a) E13.5 embryos of the genotypes indicated were removed from timed pregnancies and imaged under a dissecting scope. (b) E15.5 embryos imaged as described above. Note that size, development, and pallor appear to be improved in embryos with hypomorphic Thoc1 alleles (H). (c) Protein was extracted from E15.5 embryos of the genotypes indicated and analyzed by Western blot assay for Rb1 and Thoc1 protein expression. Actin served as a protein loading control. (d) Protein was extracted from matched placentae from the embryos analyzed in panel c and analyzed by Western blotting as described above. Note the Rb1 loss and reduced Thoc1 in the relevant genotypes.