Figure 3.

(A) Comparison of body weight in male knockout (n = 4), heterozygous (n = 5), and wild-type (n = 5) littermates. Similar results were observed in 21 female littermates (data not shown). Error bars represent SEM. (B) Survival curves for homozygous knockout mice (n = 11) and wild-type and heterozygous littermates (n = 24). All homozygous knockout mice died by day 60; no deaths occurred among wild-type and heterozygous littermates. After these studies were completed, we have observed more than 75 homozygous knockout mice, and only 4 have survived beyond 60 days—2 died at day 74, 1 died at day 90, and 1 died at day 100.