EVIDENCE OF GENETIC-HETEROGENEITY IN A BALB C MOUSE COLONY AS DETERMINED BY DNA-FINGERPRINTING/

A genetic monitoring of the BALB/c mouse foundation colony in our anim al facility was carried out. The techniques of choice were skin grafti ng, coat colour test, flow cytometric analysis for H2 antigens (loci H 2-D and H2-A), electrophoretic analysis of isoenzymes (loci Idh1, Pep3 , Es3 and Mod1), PCR-amplified microsatellites (loci Igh-V, Ngfg, lau, Crp, Igh, D16Mit5, D3Mit49 and D17Mit16) and DNA fingerprinting (mult ilocus probes 33.6, 33.15 and (CAC)(5)). No evidence of genetic contam ination was found, ruling out the possibility of an outcross with AKR, the other albino strain maintained at the facility. Nevertheless, DNA fingerprint patterns revealed evidence of genetic heterogeneity in fo ur out of nine lines of the nucleus colony, interpreted as minisatelli te mutations favoured for a single line system with more than 40 gener ations of separation from the ancestral pair. These mice are mainly us ed in cancer and immunological research within the institute.