NOVEL PUTATIVE FRAGILE SITES OBSERVED IN FELINE FIBROBLASTS TREATED WITH APHIDICOLIN AND FLUORODEOXYURIDINE

Fragile sites are non-randomly distributed chromosomal breaks and gaps observed in the cells cultivated under certain conditions. Feline fra gile sites were analyzed using skin fibroblast strains after the treat ments with aphidicolin and fluorodeoxyuridine in combination with caff eine. Three aphidicolin-induced fragile sites (Alq21, C2q13 and E1p21) as well as a folate-sensitive site (B1q14) were observed in all the 3 fibroblast strains tested for each treatment group. The loci in Alq21 and B1q14 are very close to that reported previously for peripheral b lood lymphocytes and lung cells. Two chromosomal,break points in C2q13 and E1p21 seem to be new fragile sites. Fifteen candidates for feline fragile sites were also assigned their locations in feline chromosome s. Both the incidence and distribution of feline fragile sites in skin fibroblasts seem to be different at least in part from those in lymph ocytes.