gametogenesis

Definition: Gametogenesis is the development of diploid germ cells into either haploid eggs or sperm, (respectively oogenesis and spermatogenesis). It is different for each species but the general stages are similar.

The oogenesis and the spermatogenesis have many features in common, they both involve:
 meiosis
 extensive morphological differentiation
 incapacity of surviving for very long if fertilization does not occur.

Despite their homologies they also have major differences:
 Spermatogenesis has equivalent meiotic divisions resulting in four equivalent spermatids while oogenic meiosis is asymmetrical: only one egg is formed together with three polar bodies.
 Different timing of maturation: oogenic meiosis is interrupted at one or more stages (for a long time) while spermatogenic meiosis is rapid and uninterrupted.

References

 Simpson AJ, Caballero OL, Jungbluth A, Chen YT, Old LJ. Cancer/testis antigens, gametogenesis and cancer. Nat Rev Cancer. 2005 Aug;5(8):615-25. PMID: 16034368