Comparative Data of the Chromosome Fragility in Five Wild Small Mammal Species

Abstract

ABSTRACTSmall mammals are widely used as suitable indicators of environmental pollution and genotoxic damage.The present investigation of the karyotype sensitivity to the influence of a strong mutagen was held under strictly controlled laboratory conditions. The data about the chromosome aberrations induced by treating of Mitomycin C (3.5 mg/kg) in bone marrow cells have been analyzed. The structural changes in the chromosomes including laboratory white mice ICR as well as five species small rodents—Clethrionomys glareolus (Schreber, 1780), Apodemus flavicollis (Melchior, 1834), Microtus levis (Miller, 1908), Mus spicilegus (Petényi, 1882) originating from Rila Natural Park, Vitosha Nature Park, Kresna Gorge and the vicinities of Pleven region were compared.The analysis was performed according to the protocol described by Preston et al.(1987).All treated groups of small mammals investigated showed significantly higher percentage of damaged cells in comparison with their own untreated controls (p ≥ 0.99).Rodent species under present investigation have presented significantly lower sensitivity of their chromosome set when compared to the laboratory mice ICR (p ≥ 0.99). The lowest chromosome aberrations value (in%) was expressed within the specimens in Microtus arvalis (10.29 ± 0.38) while the highest sensitivity was shown in Mus spicilegus (21.5 ± 3.03). In the four other species investigated quite close values about the number of induced chromosome aberrations were expressed.These findings have important implications for the use of zoomonitors as bioindicators in ecotoxicology and in application of genotoxicity findings in laboratory animal models to natural populations.