Ultrastructural study of acrosome formation in mongolian gerbil (Meriones unguiculatus)

Spermatogenesis is a complex and very well organized process lasting from 3 0 to 75 days in mammals. The spermatogenic process has been described mainl y in laboratory mammals, such as the rat, while correspondent studies in wi ld animals are scarce. The gerbil (Meriones unguiculatus) is a small rodent native of the arid regions of Mongolia and China. Few reports are availabl e on reproduction in the male Mongolian gerbil. The present study provides the first description of the ultrastructural alterations in spermatid cytop lasm and nucleus, with particular reference to acrosome formation in gerbil s. The testes were processed by conventional transmission electron microsco py technique. Based on the development of the acrosomal system and changes in nuclear morphology, the transformation of spermatids in spermatozoon was divided into 15 steps. There were four phases in the spermiogenesis proces s in the gerbil: Golgi, cap, acrosomal and maturation phases. This provides the foundation for a variety of future studies of the spermiogenesis of th is animal. (C) 2000 Harcourt Publishers Ltd.