FIGURE 4.

TCRβ recombination and TCRβ-mediated Ccnd3-dependent DN thymocyte proliferative expansion cooperate in αβ T cell development. A. Representative flow cytometry analysis of CD4 and CD8 expression on total thymocytes isolated from littermate or age-matched Ccnd3^-/- (n=4) and Rag1^C/CCcnd3^-/- (n=5) mice. The average number of total thymocytes for each genotype is indicated in parentheses, and the frequencies of cells in the DN, DP, CD4⁺ SP, and CD8⁺ SP quadrants are indicated on the plots. B. Graph showing the average numbers of DN and DP thymocytes from Ccnd3^-/- and Rag1^C/CCcnd3^-/- mice. Error bars are standard error of the mean. The line with an asterisk above indicates a significant difference (p≤0.05). A and B. This experiment was independently performed three times, each time on at least one mouse of each genotype. C. Representative flow cytometry analysis of TCRβ and Vβ10 or Vβ14 expression on total thymocytes isolated from littermate or age-matched Ccnd3^-/- and Rag1^C/CCcnd3^-/- mice. The frequencies of cells in the depicted TCRβ^intermediate gate are indicated. D. Graph showing the average frequencies of TCRβ^intermediate cells expressing Vβ10 or Vβ14 in thymocytes from Ccnd3^-/- (n=4) and Rag1^C/CCcnd3^-/- (n=5) mice. Error bars are standard error of the mean. Lines with asterisks above indicate significant differences (p≤0.05). C and D. This experiment was independently performed three times, each time on at least one mouse of each genotype.