Meiosis,the process by which the ovary and testis produce haploid gametes from initially diploid cells,is essential for sexual reproduction in mammals.This process,initially described in the late 19th and early 20th century using model organisms such as sea urchins,worms and fruit flies,continues to attract extensive interest from reproductive biologists due to its centrality in gametogenesis.The simple observational techniques used to initially describe meiosis have in more recent times given way to mechanistic molecular,cellular and biochemical approaches.