FIG. 4.

Testis weight and sperm production in TR4^+/+ and TR4^−/− mice. (A) Comparison of testis weights from TR4^+/+ and TR4^−/− mice. Testes from TR4^+/+ mice and TR4^−/− mice were removed, and the weights of testes were determined. At the different age points, two or three mice were used. (B and C) Comparison of sperm counts (B) and motility (C) from caudae epididymides between TR4^+/+ and TR4^−/− mice. The sperm from caudae epididymides from more than five TR4^+/+ and TR4^−/− mice, all at 2 to 3 months of age, were counted by hemacytometer under phase-contrast microscopy for total sperm (B) and sperm motility (C). Results are means ± standard deviations of at least five mice.