Sexual identity

“Animal germ cells differentiate as sperm or eggs, depending on their sex. Somatic signals tell germ cells whether they reside in a male or female body, but how do germ cells interpret those external cues to acquire their own sexual identity? A critical aspect of a germ cell's sexual puzzle is that the sperm/egg decision is closely linked to the cell-cycle decision between mitosis and meiosis.” Judith Kimble, J. and Page, D. The Mysteries of Sexual Identity: The Germ Cell's Perspective, Science 20 April 2007, V. 216, no. 5823, p. 351.