"I contain multitudes": Chimeras, cells and the materialization of identities
This dissertation traces the biomedical networks through which human chimeras are clinically constituted. Chimeras are organisms in which two or more genetically distinct cell populations co-exist. Unlike their experimentally produced counterparts (often interspecies mixtures), human chimeras arise spontaneously when fraternal twin embryos fuse in the womb. While undoubtedly a rare occurrence, the true incidence is unknown because many chimeras have no visible signs of their composite being. Hence, chimeras are produced in an inadvertent encounter with the laboratory, during blood donation or tissue typing, for example. A subtype of chimerism, called microchimerism, occurs when the second cell population is tiny. The main context in which microchimerism is discussed in biomedical research is cell exchange between women and their fetuses, now thought to be a normal event during pregnancy. Human chimerism has existed since the 1950's, and microchimerism has become a research theme only in the last decade
Thesis, Dissertation, English, 2006
2006