|MadSci Network: Development|
Dear Robert, As you may know all living organisms are made of cells. A sperm is a living cell but it is a highly specialized type of cell. A sperm cell is formed through a complex set of cell divisions, differentiation and maturation process called spermatogenesis. Spermatogenesis occurs in an organ in the male called the testis. The testis is the only organ in which sperm cells are made and reside. You cannot artifically create a sperm cell. You can culture mature the body in the laboratory. Spermatogenesis begins when a young male hits puberty. Before puberty, the immature germ cells called spermatogonia reside in the testes. They migrated to the testes during embryonic development and they stay "immature" until they received certain hormonal and biochemical signals that occur once a young man hits puberty. The spermatogonia then go through a series of divisions in which they are eventually transformed into a cell called a spermatozoa. The cells at these different stages are called: spermatogonia, spermatocytes and spermatids. The entire process of spermatogensis in a human male takes approximately 60 days. The spermatids are gradually transformed into mature sperm. This is known as spermiogenesis. The mature sperm has a tail which enables them to propel themselves. If you would like to read more about spermatogenesis, I would suggest reading, Alberts, B et.al., 1994, "The Molecular Biology of the Cell," pp1026-1027 or consult basic biology textbook. If you have more specific questions, please feel free to email me. Elsa Lee
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