Mutagenicity of the mycotoxin diacetoxyscirpenol on somatic and germ cells of mice

The study was conducted on both somatic and germ cells in addition to the sperm morphology analysis. Diacetoxyscirpenol [DAS] treatment resulted in a highly significant reduction [P <0.01] in mitotic activity at all the doses tested, confirming that DAS is a potent protein and DNA synthesis inhibitor. In the somatic cells [bone marrow], the observed chromosome abnormalities were chromatic gaps, breaks, centromeric attenuation and endomitosis. At single dose experiment, significant abnormalities were observed only after high dose treatment, they mainly consisted of chromatoid gaps, centromeric attenuation and endomitosis [4.2 + 1.3, 4.2 +/- 2.4, respectively] and aneuploids were also observed [5.8 +/- 1.6]. In contrast, at the repeated dose experiment similar abnormalities were also observed with some significance, but no systematic relation could be settled. The present results confirmed a positive correlation between cytogenetic damage and sperm abnormality. The results also proved that DAS is a very toxic mycotoxin. The most important severity of it, in addition to including chromosomal abnormalities, is its inhibition of DNA synthesis and subsequently affecting the cell cycle and division

Chromosomal aberrations and sister chromatid exchanges induced by cyclophosphamide

Experiments were performed in order to gain informations about the ability of cyclophosphamide [CPA] to induce chromosomal aberrations in the rabbit bone marrow cells and sister chromatjd exchanges in lymphocyte blood cultures. Rabbits were treated with two different doses of CPA for in vivo and in -vitro experiments. The mitotic index was highly decreased with increasing CPA dose compared with control. Structural chromosomal aberrations which were observed in the present study consisted mainly of chromatid deletions, fragments, gaps; and stickiness. CPA proved to possess a powerfull genotoxic effect through its induction to sister Chromatid exchanges [SCEs] in cultured lymphocyte cells. Both structural chromosomal aberrations and SCEs were significantly increased in treated rabbits compared to the control one

Cytogenetic studies of chemoprophylactic agents on postimplantion mice embryo in presence of nitrosamine: effect of soybean

Nitrates, nitrites and dimethylamine are a components reacts in the gastro-intenstinal tract synthesing the powerful hepatoxic and carcinogenic dimethylnitrosmamine. This study aimed to evaluate the cancer protector named soybean. This evaluation had been tested in laboratory mice in the presence of nitrosamine as a cancer induced. For pursing the evaluation, four groups of mothers and their embryos were used. The first group was the control group, the second group was a mothers treated with Dibutylamine plus nitrite [DBA + NO3], the third group was a mothers fed with a diet containing a 30% soybean, while the fourth group was mothers fed with SB and DBA + NO3. Generally the results showed a decrease in the percentage of gestation in all the treated animals in comparison with the control group, while there was no significant difference [P>0.05] in the mean numbers of impanation sites and living fetuses in all the treated animals. Moreover the cytogenetical analysis revealed that soybean produced a non significant ratio of chromosome abnormalities when tested using the Chi-square method

Constitutive heterochromatin in sheep and goat chromosomes

Heterochromatin [constitutive heterochomatin] as revealed by C-banding was found to be mostly located in the centromeric regions in domestic sheep and goats. Considerable variation was, however evident in the size of the C-bands both within and between the two species. Some evidence was found for a reduction in the amount of the centromeric heterochromatin in the bi-armed chromosomes relative to the acrocentric one. These findings are discussed in relation to karyotype evolution between the two species