Figure 3

Embryonic growth is exquisitely sensitive to Cdkn1c levels. A) Image of a wild type and a transgenic embryo from line 5A4 (two copies) at E16.5 shows demonstrable growth retardation. The embryos appear normally proportioned. B) A comparison of wild type and transgenic embryo weights at E13.5 for line 5D3 (single copy unmodified BAC, Tg n = 22, WT n = 21). These embryos are from 129/Sv females mated with transgenic males maintained on an MF1 background. Transgenic embryos weigh significantly less than wild type embryos (86%, P = 7.2 × 10^-7). C) A comparison of wild type and transgenic weight at E13.5 of embryos for line 10–15 (three copy BAC with an inactive transgenic Cdkn1c locus and no excess Cdkn1c, Tg n = 30, WT n = 22). The line was maintained on a 129/Sv background. Transgenic embryos are not significantly different in weight to wild type embryos (104%, P = 0.24). D) A comparison of wild type and transgenic weights at E13.5 of embryos inheriting a targeted Cdkn1c allele maternally (null for Cdkn1c, Tg n = 19, WT n = 16). The line was maintained on a 129/Sv background. Transgenic embryos weigh significantly more than wild type embryos (111%, P = 0.008).