Analysis of chromosome damage by sister chromatid exchange (SCE) and redox homeostasis characterization on sheep flocks from Sardinian pasturelands

The Cytogenetics of the Water Buffalo: A Review

The water buffalo (Bubalus bubalis), also known as the Asian buffalo, is an essential domestic bovid. Indeed, although its world population (~209 million heads) is approximately one-ninth that of cattle, the management of this species involves a larger human population than that involved with raising cattle. Compared with cattle, water buffalo have been understudied for many years, but interest in this species has been increasing, especially considering that the world population of these bovids grows every year-particularly that of the river buffalo. There are two genera of buffalo worldwide: the Syncerus (from the African continent), and the Bubalus (from the southwest Asian continent, Mediterranean area, southern America, and Australia). All species belonging to these two genera have specific chromosome numbers and shapes. Because of such features, the study of chromosomes is a fascinating biological basis for differentiating various species (and hybrids) of buffaloes and characterizing their karyotypes in evolutionary, clinical, and molecular studies. In this review, we report an update on essential cytogenetic studies in which various buffalo species were described from evolutionary, clinical, and molecular perspectives-particularly considering the river buffalo (Bubalus bubalis 2n = 50). In addition, we show new data on swamp buffalo chromosomes.

Analysis of chromatin instability of somatic cells in sheep

Cytogenetic tests are highly reliable, sensitive indicators of the early effects of genomic instability. Their results provide information on the organism’s susceptibility to exogenous and endogenous factors and are measures of the degree of repair of DNA damage. Our study assessed spontaneously occurring damage in following four breeds of sheep: Polish Heath, Polish Lowland (Zelazna variety), Polish Blackhead, and Berrichon du Cher. Instability was identified using the following three different tests: a sister chromatid exchange (SCE) assay, identification of fragile sites, and the comet assay. The distribution of instabilities varied depending on the breed. The mean frequency of SCEs was 5.13 ± 1.58, whereas that of fragile sites was 3.30 ± 1.24. The mean level of DNA damage (% head DNA) was 96.52 ± 6.59. The most damage to genetic material was observed in the Berrichon du Cher sheep, and the least in the Polish Heath sheep. The tests used are reliable biomarkers of genome stability in animal breeds, as well as in individuals within breeds.

Cytogenetic tests reveal no toxicity in lymphocytes of rabbit (Oryctolagus cuniculus, 2n=44) feed in presence of verbascoside and/or lycopene

Phenylpropanoid glycosides (PPG), like other phenolic compounds, are a powerful antioxidants and the Verbascoside (VB) is one of the most active of them. A previous study, by using in vitro exposure of blood human lymphocytes to Verbascoside, reported a significant increasings of chromosome fragility compared to control. In the present study, four homogeneous groups of rabbits were used to test in vivo the VB and/or Lycopene (LP) by feeding the animals without VB and LP (control), in presence of VB or/and LP for 80 days. Lymphocyte cell cultures were performed in three different times: 0, 40 and 80 days of the experiment and the cytogenetic tests that we used [CA-test (Chromosome Abnormalities in terms of chromosome and chromatid breaks) and Sister Chromatid Exchange (SCE-test)] have revealed no mutagenic effects on chromosomes. Indeed, mean values/cell of CA and SCE decreased during the experiment with some difference among and within groups, with significant decreasing value only for some group. The study shows clear evidence that diets rich in Verbascoside (and/or Lycopene) do not originate any mutagenic activity, resulting no cytotoxic for the animals and, suggesting a possible their use in both animal and human diets.

Evaluation of genotoxic effects of 3-methyl-5-(4-carboxycyclohexylmethyl)-tetrahydro-2H-1,3,5-thiadiazine-2-thione on human peripheral lymphocytes

CONTEXT

Tranexamic acid is commonly used for curing abnormal bleeding in a variety of diseases. In a previous study, 12 different tetrahydro-2H-1,3,5-thiadiazine derivatives were synthesized from the amine group of tranexamic acid. Their antifibrinolytic and antimicrobial activities were compared with tranexamic acid. 3-Methyl-5-(4-carboxycyclohexylmethyl)-tetrahydro-2H-1,3,5-thiadiazine-2-thione (3-MTTT) was the most remarkable one, which may be used as a drug.

OBJECTIVES

In vitro genotoxicity of 3-MTTT was investigated using chromosome aberrations (CAs), sister chromatid exchanges (SCEs), micronucleus (MN) and comet assays.

MATERIALS AND METHODS

Various concentrations 0.78, 1.56, 3.13, 6.25, 12.50 and 25.00 μg/mL of 3-MTTT were applied to lymphocytes obtained from two donors for periods of 24 and 48 h. A negative (distilled water), a solvent (2:1 PBS:10% NaOH for cultured lymphocyte, and PBS for isolated lymphocytes) and a positive control (MMC for cultured lymphocytes and H₂O₂ for isolated lymphocytes) were also maintained.

RESULTS

While this compound did not increase the frequency of abnormal cells and CA/cell ratio compared to negative control (except 48 h, 25 μg/mL), it significantly increased the frequency of SCEs at the four highest concentrations at both treatment periods (except 6.25 μg/mL, 48 h). It significantly decreased the MI in all the concentrations at 24 h (except 0.78 μg/mL) and in the highest three concentrations at 48 h. This compound did not significantly increase the frequency of MN and DNA damage compared to negative control. This compound did not affect the replication and nuclear division index.

DISCUSSION AND CONCLUSION

Our results demonstrated that this compound does not represent a significant risk at the genetic level in in vitro human lymphocytes.

In vitro evaluation of the mutagenic and cytostatic effect of Tamaron, Lannate and Manzate alone and in mixture

Pesticides are often used in agriculture, especially in floriculture. They are frequently applied in binary or ternary mixtures. Nevertheless, their impact on the genetic material has been scarcely explored. In this study, the mutagenic and cytostatic effect of three widely used pesticides, alone and combined, were analyzed. Briefly, lymphocytes cultures were obtained from peripheral blood samples of five healthy donors to determine the sister chromatid exchange and the replicative index (RI). Then, lymphocytes were exposed to Tamaron (100 ppm), Lannate (200 ppm) and Manzate (300 ppm) alone and combined. For the binary mixtures, the concentrations used were 50 ppm of Tamaron, 100 ppm of Lannate and 150 ppm of Manzate. For the ternary mixtures the following concentrations were used: Tamaron (33 ppm), Lannate (70 ppm) and Manzate (100 ppm). Finally, differential staining was performed. It was found that the frequency of SCE/cell showed a significant difference (P ≤ 0.05) between the control (2.66) and the individual treatments of Tamaron (4.87), Lannate: (5.12) and Manzate (4.23). Also, the values of the SCE in the binary mixture of Tamaron+Lannate (5.57), Tamaron+Manzate (6.06) and Lannate+Manzate (6.22) and the ternary mixture (6.63) were statistically different compared to the control. In the RI there was a significant difference between the control (1.98) and the Manzate (1.87). RI differences were also statistically significant (P ≤ 0.05) in mixtures of Tamaron+Lannate (1.64), Tamaron+Manzate (1.63), Lannate+Manzate (1.69) and total mixture (1.53). Therefore, it is suggested that these pesticides alone and in mixtures have both mutagenic and cytostatic synergistic effect in human lymphocytes in vitro.