The genetics and cell biology of spermatogenesis in the nematode C. elegans

Creation of mutants that affect spermatogenesis is very challenging in most experimental systems, especially mammals. The main reason this is true is because "absence of successful mating" is a negative result that can occur for a wide variety of trivial, irrelevant reasons. The C. elegans hermaphroditic mode of reproduction has unusual features that facilitate analysis of spermatogenesis. Normally, hermaphrodites are virtually 100% self-fertile and spermatogenesis defective mutants are self-sterile. A candidate spermatogenesis defective mutant will produce cross-progeny after mating to a wild type male, showing that the presence of sperm is both necessary and sufficient to restore fertility to the sterile hermaphrodite. This has allowed selection of a large number of spermatogenesis defective mutants. In this article, I will review spermatogenesis, how mutants are made and what has been learned about the identified genes and their roles during development and fertilization.