Review: Genetics of Spermatogenesis

Development of mammals is usually initiated by fertilization of an egg by a sperm. The sperm and the egg have distinct roles to play in launching development of a new generation. The sperm must seek out the egg, fuse with it and deliver its precious haploid nucleus. The egg, on the other hand, must make itself apparent to the sperm and be capable of responding appropriately to its contact. That response allowing a sperm of its own species to fuse with it, once fusion has occurred; the egg exaggerates its defenses to prevent the fusion of additional sperm. It also initiates a sequence of events that enable the sperm nucleus to fuse with the egg nucleus to form the zygote nucleus and begin the complicated process that produces an embryo that develops into an organism consisting of many different cell types that are organized into tissues and organs to enable the organism to function like its parents.