TUNEL-positive germ cells in testicular sections of age-matched control (WT) and ABP-TG mice at the ages of 90 (A&B) and 360 (C&D) days. Photomicrograph in E is from a 90 days old control mouse treated with methoxy acetic acid (MAA). Compare number of apoptotic germs cells in Fig. 7E with that in untreated WT control (Fig. 7A) and the negative control (Fig. 7F).