FIGURE 3:

R-Ras2/TC21 regulates the timely development of the pubertal mammary gland. (A) qRT-PCR analysis of total RNA obtained from mammary glands extracted from the indicated stages. Prepubertal, pubertal, and adult virgins correspond to samples obtained from 3-, 8-, and 14-wk-old RRas2^+/+ female mice, respectively. Early and late pregnancy correspond to female mice within weeks 1 and 2½ of pregnancy, respectively. The early and late lactation samples were taken 1 and 2 wk after labor, respectively. The involution phase samples were taken 3.5 d after offspring weaning. Data are given relative to the expression levels obtained in virgin adult state (which was given an arbitrary value of 1). All values were normalized taking into consideration the expression levels of the housekeeping Gapdh mRNA in each sample. *p ≤ 0.05; ***p ≤ 0.001 (n = 3). (B) Representative images of carmine alum–stained mammary fat pads obtained from female mice of the indicated ages (top) and genotypes (left). Scale bars, 500 μm. One of the inguinal lymph nodes is indicated by a white asterisk. (C–F) Quantification of the total area (C), maximal length (D), number of TEBs (E), and branching points (F) of mammary glands obtained from animals of the indicated genotypes and ages. *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001 when compared with values obtained in the appropriate wild-type control (n = 5–10 animals per genotype and developmental stage).