Fig. 1.

Generation and characterization of fast muscle-specific androgen receptor knockout (fmARKO) mice. (A) Mlc1f-Cre+/+/AR-flox/Y mice were mated with AR-flox/flox mice to produce Mlc1f-Cre+/−/ARflox/Y mice (referred to as male fmARKO mice). (B) PCR analysis of tissue-specific recombination at the AR locus in different tissues from a 13-wk-old fmARKO mouse. The knockout allele (AR) is present only in skeletal muscle. (C) AR mRNA levels in skeletal and heart muscles of 13-wk-old control and fmARKO mice (n = 5 to 6/group). (D) Growth curves of control and fmARKO males (n = 6 to 13/group). Error bars indicate SEM; **P < 0.01.