Lessons from Chimeras

The chimera marmoset story reported linkurl:here;http://www.the-scientist.com/news/home/53033/ and elsewhere is fascinating; I was stunned by the possibility, not heavily noted in a lot of press, that male cells might have made it into the germline of a female - that is XY cells from a male might have developed into eggs in his female twin sister resulting in a live birth. Germline transmission of one's brothers cells is interesting enough, but the idea of XY eggs is particularly interesting -- not just for the fact that a female had her brother's baby without all that messy incest. Another interesting chimera story, this one in humans, linkurl:was noted in the media;http://www.nature.com/news/2007/070326/full/070326-1.html;jsessionid=AE244B09CB3C69822F0B1B3B2DF74872 earlier this week. In a unique event researchers ascertained that a pair of twins, one phenotypically male and one hermaphroditic with ambiguous genitalia, were both actually XX/XY chimeras of each other. The twins developed, DNA analysis suggests, from a single egg...