This Science and Technology Studies Dissertation Improvement Grant uses ethnographic and historical research methods to trace the emergence and characterization of genetic mosaics and chimeras. Four cases of human genetic multiciplicity will be compared. In each case, genetically different cell populations co-exist in a human body, or travel between bodies (calling into question the very notion of a body). Spontaneous human chimeras result from tissue exchanged between fraternal twins in utero, or the complete fusion of embryos early in development. Genetic mosaics result from a single-cell mutation, which persists in an altered cell line that proliferates in the organism's body alongside the original cell population. The term microchimerism describes the persistence of fetal cells and DNA molecules in the maternal body, and maternal cells in the child's body, both of which persist after pregnancy. Microchimerism also refers to a condition of an organ recipient in whom donor cells proliferate and persist. This dissertation uses these four cases of genetic multiplicity (chimerism, mosaicism, fetal microchimerism and transplantation microchimerism) to gain empirical, and critical, purchase on the historical and cultural specificity of the premise that humans are genetically unique and discrete. In other words, the aim is to focus closely and critically on the idea that individual identity is necessarily bound to a unique and singular genome. In contemporary biomedicine and biopolitics, genetics and identity are becoming increasingly conflated, but the chain from genes to selves is neither inevitable nor inviolable. Fieldwork for this project explores clinical and experimental situations in which humans are constructed as multiple, genetically. Laboratory researchers and technicians concerned with mosaic and chimeric phenomena sort cells and molecules into discrete categories of male and female, normal and pathological, maternal and fetal, animal and human, and self and other. This project examines the thesis that genetic identity on the microscopic level and human selves on the holistic level are co-produced and mutually stabilized. Most of the time, the genetic identity of a few cells (such as in forensic testing and prenatal screening) can be made to overlap with a self-contained individual. The cases in this study offer an opportunity to explore circumstances in which genetic heterogeneity disrupts notions of individuality and identity. Reversing this relationship, the project also examines whether socio-political notions of individuality and identity are woven into the practical assignment of genetic identity of cells and molecules in the laboratory. NSF funds will support fieldwork in the United States, Canada and the U.K., at laboratories, clinics, conferences and support groups in which knowledge about genetic mosaics and chimeras is produced, negotiated and contested. Investigators and technicians in each of the research communities will be interviewed. Patient activists who challenge the ways in which they are classified as monstrous, marginal or hybrid also will be interviewed. Participant ethnographic research will be conducted at several conferences at which researchers from different communities come together and discuss emergent technical and medical issues associated with the construction of human genetic identity and multiplicity. The intellectual impact of this dissertation project primarily is in the areas of social studies of genetics and identity, empirical work on biosociality and lay activism, and theoretical criticisms of essentialist or determinist notions of genetics. As a study of selfhood and multiplicity identified with the very material of the body and in technical practice, it supplements theoretical literatures about the self, fragmentation, and multiplicity. The broader impact and implications of this study have to do with individuals and groups who contend with biomedical characterizations of their identities. The coexistence of multiple biological identities in these individuals may provide institutional and bureaucratic bases for classifying and excluding persons. Furthermore, microchimerism research suggests that we are all genetically distributed at some level. This project will make important and timely contributions to political and technical debates about genetic identification; debates that both reify the genetic individual and, ironically, contribute to the proliferation of exceptions.
