Supporting Figure 8

Fig. 8. TβRI(AAD) transgenic mice display a lactation-deficient phenotype. (A) The percentage pup viability at weaning is shown for litters nursed by control (FVB/N) (n = 41 litters from 11 different females) and MMTV/TβRI(AAD) dams (n = 40 litters from 10 different females). (B) Growth curves of pups nursed by MMTV/TβRI(AAD) (n = 56 pups; 8 litters from 6 different females) and control (FVB/N) dams (n = 38 pups; 5 litters from 3 different females) are shown. The differences between pup weights were found to be statistically significant at each time point examined (*, P = 0.0004, Student's t test). (C) No differences in the birth weight of pups born to MMTV/TβRI(AAD) (n = 29 pups; 4 litters from 4 different females) and control (FVB/N) dams (n = 30 pups; 3 litters from 3 different females) were observed. (D) Total RNA derived from nontransgenic (FVB/N) and MMTV/TβRI(AAD) female mammary glands at different stages of development were subjected to RNase protection analysis with an antisense mouse-specific WAP riboprobe. Total RNA from FVB/N virgin and lactating mammary glands served as negative controls. M.Gl., mammary gland; Lact. M.Gl., lactating mammary gland. A mouse specific β-actin antisense riboprobe was included to control for the amount of RNA in each hybridization reaction. Undig. Riboprobes refers to the full-length riboprobes that have not been subjected to RNase digestion. Sizes (in nt) of DNA markers are indicated. WAP (E) and β-casein (F) signals from FVB/N (open bars) and MMTV/TβRI(AAD) (filled bars) mammary glands were quantified by PhosphorImager and normalized against the β-actin internal control. These ratios were then used to determine the relative fold increase in expression compared to FVB/N virgin mammary gland.