Beatrice Mintz

"In higher organisms, the cells of an individual become greatly diversified despite their identity of . How such diversification is achieved and how supra-cellular organization then comes about have remained largely obscure. A new way of getting at theses questions was formulated in ; its purpose was to subject the pivotal genotype-phenotype relationship to experimental manipulation. The intact organism was taken to be the necessary framework for such an experimental study of gene expression, and the mouse, with its wide variety of available s, was easily the most promising vertebrate species. The plan was to make artificial mice: within each, cells with different, rather than identical, genotypes would be included. ... Certain kinds of had previously been extensively employed in studies with '. ... The first indication, in a mammal, of an admixture of genotypes came with 's discovery of erythrocyte mosaicism in fraternal cattle co-twins. ..."

"s owe their existence to a population of persistently proliferating s which probably originate from the normal generative cells of that ... Normal stem cells ordinarily tend to give rise to non-dividing terminally differentiated cellular progeny; malignant stem cells, on the other hand, suffer an impairment of differentiation. Early in embryonic life, stem cells are developmentally versatile; the earliest ones, e.g., s in the mouse, are , or individually capable of forming an entire organism. s are exceptional tumors in that they contain a multiplicity of tissues, a characteristic implying that their stem cells arise from cells more developmentally primitive than is the case in other malignancies."

"She made foundational discoveries and revolutionized many tools and techniques of that paved the way for tremendous progress in our understanding of cancer."

"Beatrice Mintz, known as “Bea” to her friends, was a developmental geneticist. ... Her pioneering work had a major impact on many different areas of science. She began her career addressing one of the most complex and fascinating questions of development: how the many different and diverse tissues in an organism are initiated and develop from a single fertilized egg. In the early 1960s Bea—at about the same time as in Poland and in Philadelphia—generated the first chimeric mice by combining early, genetically distinct, mouse embryos. She had contemplated this experiment for many years at the and began to work seriously on it after moving to (discussing the project with her colleagues) … And indeed, this manipulation of embryos was a breakthrough to a new era of experimental work in mammalian development. (Bea did not like the designation “chimera” because of its association with “monsters” in Greek mythology; she described these mice as “allophenic.”)"