GENETIC DIVERSITY AFFECTS TESTICULAR MORPHOLOGY IN FREE-RANGING LIONS(PANTHERA LEO) OF THE SERENGETI PLAINS AND NGORONGORO CRATER

Reduced genetic variability is known to adversely affect ejaculate qua lity in inbred lions (Panthera leo) physically isolated in the Ngorong oro Crater compared with outbred lions inhabiting the adjacent Serenge ti Plains in East Africa. This study compared the histomorphology of t esticular biopsies from these two lion populations. Ngorongoro Crater lions had fewer (P<0.05) seminiferous tubules with spermiogenesis and fewer (P<0.05) spermatids per seminiferous tubular cross-section than Serengeti Plains lions, although seminiferous tubular diameter did not differ (P>0.05) between populations. Interstitial areas were greater (P<0.05) in Crater than in Plains lions, but no qualitative difference s were evident, suggesting that proportionately less testicular area w as occupied by seminiferous tubules in Crater lions. None of the lions ir,either population had evidence of testicular degeneration. Overall results suggest that inbred Crater lions have reduced spermiogenesis and less total seminiferous tubular area per testis. These data furthe r support the premise that genetic homogeneity compromises reproductiv e traits in free-living, male African lions.