Testicular changes associated with the initiation of spermatogenesis

Testicular changes preceding and accompanying the initiation of spermatogenesis are reviewed. The complex cellular changes occurring in the developing testis are found to be particularly well defined with the use of electron microscopy. The findings suggest that electron microscopic examination may be useful in the evaluation of male infertility, especially in those cases in which clinical and laboratory findings are negative or inconclusive. The amount of tissue required is minimal and can be taken as part of the regular testicular biopsy. The additional information provided by electron microscopy can be used to clarify the observations made on routine light microscopic study and may also lead to better understanding of the pathologic changes occurring in some of the less well understood forms of male infertility.