2 Insights into Development and Genetics from Mouse Chimeras

Clonal analysis of patterns of growth, stem cell activity, and cell movement during the development and maintenance of the murine corneal epithelium

“…This would be analogous to the formation of stripes in the periphery of the retinal pigment epithelium (RPE) of chimeric mice that are composed of a mixture of albino and pigmented cells (reviewed in West, 1999). In early development of the RPE, mitotic activity is observed throughout the tissue but later becomes restricted to the periphery-a pattern of proliferation that produces the observed distribution of pigmented radial stripes at the edge of the RPE only (Bodenstein, 1986;Bodenstein and Sidman, 1987a,b).…”

“…The production of chimeras by aggregation of two eight-cell embryos, in which one of the contributing embryos carries a marker by which its cells can be identified, is an established method for clonal analysis of growth patterns in the mouse (Ng and Iannaccone 1992;West, 1999). Female mice that carry a marker transgene on the X chromosome, which is subject to random X-inactivation, may produce mosaic patterns of transgene activity that also allow investigation of cell lineages (Tan and Breen, 1993).…”

Analysis of mouse eye development with chimeras and mosaics

“…An early histological study of chimeras and X-inactivation mosaics suggested that between E12.5 and the adult, the number of coherent clones in the RPE increased about 3-fold and the mean number of cells per coherent clone increased by 4 to 4.5-fold (West, 1976a). Although such estimates of clone sizes and numbers may not be accurate in some situations (Schmidt et al, 1986) they still provide a valid means of comparing different groups of mosaics or chimeras (West et al, 1997;West, 1999).…”

Quantitative Fluorescent PCR (QF-PCR) on microsatellites, a fast and quantitative method to assay chimeric DNA samples in honeybees (Apis mellifera)

“…The study of chimeras has already provided in-depth knowledge about animal development and genetics (West, 1999), and is constantly reaching new areas and applications. Traditionally, chimeric individuals have been detected and studied by use of coat colour or biochemical markers, however, in recent years DNA-based methods such as Fluorescence.…”

“…They have shown to be instrumental for understanding important issues in developmental biology (reviewed by West, 1999). The techniques for making and studying chimeras have been established for a large number of organisms, including the fruit fly (Illmensee, 1968), mouse (Tarowski, 1961) and zebrafish (Lin et al, 1992).…”