The Effect of Bromodeoxyuridine on Spontaneous Sister Chromatid Exchange Frequency in Rabbit (<I>Oryctolagus cuniculus</I>) and Coypu (<I>Myocastor coypu</I>) Chromosomes

Abstract

The effect of bromodeoxyuridine on spontaneous sister chromatid exchange frequency in rabbit (Oryctolagus cuniculus) and coypu (Myocastor coypu) chromosomes. Folia Biologica (Kraków) 64: 89-96. The sister chromatid exchange test is regarded as a highly sensitive cytogenetic assay. It measures chromosome sensitivity to particular damage factors and provides information on control and repair mechanism performance. It is instrumental in the early identification of the effects of noxious factors present in the habitat. This investigation was aimed at identifying sister chromatid exchange sites in coypu and rabbit chromosomes, as well as determining the spontaneity of the process by applying different BrdU doses. The chromosomes were obtained from an in vitro culture of blood lymphocytes, supplemented with 4 different BrdU doses: 0.25/0.5/1.0/2.5 µg/ml in order to identify spontaneous sister chromatid exchanges in both animal species. The chromosomes were stained according to the FPG method. Spontaneous SCEs were observed in coypu at a concentration of 1.0 µg/ml, and in rabbits at 0.5 µg/ml. The mean SCE/cell incidence was 1.41±1.15 in coypu, and 2.69±2.14 in rabbits. Differences in SCE incidence were identified between the analysed animal species and the applied BrdU doses.

Assessment of genome stability in various breeds of cattle

“…Many scientists investigating sister chromatid exchanges claim that the sites where exchanges occur are not accidental and show species-specific variation. The location of SCEs in the chromosome is likely to be associated with different arrangements of heterochromatin in different species [32,50]. According to Latt [51] and Iannuzzi et al [52], SCEs are generated in the G-bands and in the areas between the bands.…”

“…According to many researchers, exchanges take place less frequently in the terminal part of chromosomes [32,53]. On the other hand, Kuchta-Gładysz et al [50,54] have reported a very high level of damage in the distal part of the chromosome. Damage in this part of the chromosome is caused by oxidative stress, which results in single-strand DNA breakage in the telomeres.…”

Determination of cytogenetic markers for biological monitoring in coypu (Myocastor coypu)

“…For the purpose of biomonitoring, it is necessary to know the level of spontaneous chromosomal and DNA damage in the population because it allows determining acceptable normal values and provides baseline data in the case of unexpected exposure to environmental or nutritional factors. In our previous study, we assessed spontaneous SCEs in coypu chromosomes (Kuchta‐Gładysz, Wójcik, Szeleszczuk, Niedbała, & Wojnar, 2016). To the authors’ knowledge, until now no studies have investigated genomic instability in coypu using FS, BLM, MN, and comet assays.…”