Sister chromatid exchange as an index of chromosome instability in chondrodystrophic chickens (Gallus domesticus)

Abstract

Commercially bred broiler chickens reared in inadequate breeder-created habitat conditions often suffer from a disease that afflicts their lower limbs, chondrodystrophy. The sister chromatid exchange (SCE) test makes it possible to detect chromosome instability that corresponds with elevated vulnerability of the organism to genotoxic factors of a mutagenic and carcinogenic nature. The frequency of SCE in chromosomes of chondrodystrophic and healthy broilers was analyzed. Chromosome preparations were obtained from our in vitro culture of peripheral blood lymphocytes stained using the fluorescence plus Giemsa technique. The SCE/cell mean of the population under analysis was 6.8 ± 1.6. The SCE/cell mean in the chromosomes of the chondrodystrophic chickens was 8.5 ± 1.0. The healthy chickens had an SCE/cell mean of 5.1 ± 1.3. Statistically significant differences were identified between both chicken groups. Moreover, a higher SCE/cell mean was observed in the males: 6.9 ± 1.7 compared with 6.7 ± 1.7 in the females. However, this difference was not statistically significant. Additionally, SCE incidence in the first 3 biggest autosome pairs (1, 2, 3) was analyzed in detail. The number of identified SCE was proportional to chromosome length. The most exchanges were observed in the proximal region of the chromosomes under analysis.