Animal Probes and ZOO-FISH

Abstract

Zoo-FISH (fluorescence in situ hybridization) (Scherthan et al. 1994), also known as cross-species chromosome painting or comparative chromosome painting, essentially describes the use of whole chromosome- or chromosomal arm- or region-specific painting probes to delimit homologous segments (chromosome or chromosomal segments with evolutionarily conserved synteny) in other species by means of FISH. Like most conventional cytogenetic methodologies, the technique of chromosome painting was first introduced to human cytogenetics in 1988 (Pinkel et al. 1988). Wienberg and colleagues (1990) were among the pioneers who intro-duced chromosomal painting to the field of comparative cytogenetics of primates. They established the first genome-wide chromosome maps between human and a Japanese macaque. In the beginning, painting probes were derived from libraries of human chromosome-specific DNA clones. Limited by the availability of painting probes and technical difficulties in comparing distantly related species, early cross-species chromosome painting experiments primarily used apes and Old World monkeys (Jauch et al. 1992). Scherthan and colleagues (1994) were among the first to demonstrate the feasibility of comparing species as distantly related as those from different orders. Meanwhile, the invention of degenerate oligonucleotide-primed PCR (DOP-PCR, Telenius et al. 1992a), coupled with chromosomal sorting by flow cytometry, made it possible to generate painting probes for any given vertebrate species (Telenius et al 1992b; Rabbitts et al. 1995; Yang et al. 1995) and to carry out multidirectional cross-species chromosome painting. The whole set of human chromosome-specific painting probes derived from DOP-PCR were made commercially available around 1992, and the whole set of chromosome painting probes for mouse became available in late 1995. Human chromosome-specific