Zenovia Olteanu

Morphometric pattern of somatic chromosomes in three Roma- nian seabuckthorn genotypes

Abstract The somatic chromosomes and karyotype traits of three Romanian genotypes (coded as CB-1, S-16, L-4) of Hippophae rhamnoides L. have been studied. Diploid chromosome number is 2n = 24. The karyomorphological data show that the complements have small chromosomes (1.33 ± 0.014 – 2.80±0.01 μm, for CB-1 genotype; 1.13 ± 0.029 – 2.90 ± 0.029 μm, for S-16; 1.15 ± 0.099 – 2.88 ± 0.024 μm, for L-4 genotype) and the length of haploid complements is 23.97 μm, for CB-1, 22.20 μm, for S-16, 21.73 μm, for L-4. In CB-1 and S-16 male genotypes, the putative Y-chromosome has larger sizes than X-chromosome and it is of metacentric type (CI = 45.77, r = 1.18, for CB-1; CI = 46.22, r = 1.15, for S-16). The L-4 female karyotype is constituted by twelve pairs of morphologically similar chromosomes. The karyotype formulae are 2n = 24 = 13m + 11sm (putative male: 22 + XY), for CB-1 genotype, 2n = 24 = 18m + 6sm (putative male: 22 + XY), for S-16 genotype, respectively 2n = 24 = 22m + 2sm (L-4 genotype, considered as female: 22 + XX). The small size of chromosomes (< 3μm), the presence of only two morphometric chromosome types and preponderance of metacentrics confer a relatively high degree of symmetry to the studied karyotypes. Our results show a low intraspecific karyotype variation.

Evaluation of Roundup-induced toxicity on genetic material and on length growth of barley seedlings.

The study was performed in order to evaluate Roundup-induced genotoxic effects in Hordeum vulgare L. cv. Madalin root meristems and to analyze herbicide impact on length growth of barley seedlings. Caryopses were treated for 3 hours and 6 hours with 0.1%, 0.5%, 1.0% and 2.0% Roundup solutions (v/v), containing 0.36 mg ml-1, 1.8 mg ml-1, 3.6 mg ml-1 and 7.2 mg ml-1 glyphosate active ingredient. Mitotic index decreased in both exposure times with concentration increase. In 3-h treatment, its average values decreased from 4.73 ± 0.31% to 1.51 ± 0.43%, whereas in 6-h treatment this parameter declined from 3.86 ± 0.92% to 0.62 ± 0.15%. The highest ana-telophase aberration rates were noted in 3-h treatments (8.91%, 9.19%, 9.47%, 11.25%, comparatively to control - 5.99%). Roundup enhanced the number of metaphase disturbances proving its noxious effect on normal functioning of mitotic spindle. Seedling growth was negatively influenced at all tested concentrations in both exposure times. The length decreased as concentration increased, so that the average length is 7.5-9 times smaller than in control at the maximum concentration, in both exposures.

The effects of a 6-OHDA induced lesion in murine nuccleus accumbens on memory and oxidative stress status

Nucleus accumbens (NAcc) are a collection of neurons that form the main part of the ventral striatum, which is a significant dopaminergic structure. Also, NAcc is thought to play an important role in reward, pleasure, laughter, addiction, aggression, fear, and the placebo effect. In the present work we were interested in studying the effects of a 6-OHDA induced lesion in the nucleus accumbens (NAcc), which is known as an important dopaminergic structure, on a specific behavioral task that involves both short term and long term spatial memory (the radial-8-arm-maze task), as well as on the oxidative stress markers (two antioxidant enzymes: superoxide dismutase-SOD and glutathione peroxidase-GPX and a lipid peroxidation marker: malondialdehyde-MDA, as well as the total antioxidant status-TAS) from the temporal lobe, which is considered to be the most vulnerable cortical area to oxygen levels fluctuations and hypoxia. Our results showed some significant effects of this lesion on the reference memory errors and time necessary to finish the test in the radial-8-arm-maze task. Additionally, increased oxidative stress status was demonstrated in the temporal lobe of the lesioned rats, as demonstrated by the high levels of lipid peroxidation and decreased total antioxidant status. Moreover, significant correlations are reported here between the behavioral parameters which we studied in the radial-8-arm-maze task and the aforementioned oxidative stress markers.