Analysis of RIα+/−,Cα2+/− animals (97% C57BL/6). (a) SEM of sperm removed from the cauda epididymis of RIα+/−,Cα2+/− adult male. (b) Percentage of sperm that are headless from wild type (n=12), RIα+/− (n=13), and RIα+/−,Cα2+/− (n=8) males. (c,d) Basal (-cAMP) and total (+cAMP) PKA activity in testis (c) and sperm (d) from wild type (n=4 or 5), RIα+/− (n=5) and RIα+/−,Cα2+/− (n=3) adult mice. * p<0.05