Number Of Diploid Cells Research Articles

Chromosomal mutations in high-yield Holstein cows

The results of the research of somatic chromosomal instability: aneuploidy and polyploidy in the blood cells of high-yield Holstein cows with the productivity of more than 9000 kg have been presented in the article. The research was conducted in JSC Vaganovo, Promyshlennovsky District, Kemerovo Region on the population of Holstein cows. Sample preparation was carried out accord- ing to P. Moorhead et al. Samples were stained using the Romanowsky-Giemsa method. The authors studied 6068 metaphase plates in a group of 30 healthy animals. Aneuploidy was counted according to the practice of N.P. Bochkov et al. The authors also analysed the ecological situation in the area of keeping and breeding cattle. Studies of soil, fodder, organs and tissues in farm animals of different species confirm that heavy metal and chemical pollutants are not contaminated in Western Siberia, and their levels are within sanitary norms. Therefore, the ecological situation in the study area should be considered safe. The study shows that the frequency of polyploidy was 0.59% in the studied sample. Tetraploidy, triploidy, and hexaploidy rates were 0.33; 0.18 and 0.06, respectively, the frequency of true hypoploidy was 0.73, and the number of diploid cells was 84.7%. The data obtained can be tentatively applied as average values and can also be used to evaluate the interior of the animals.

SOMATIC CHROMOSOMAL INSTABILITY IN HOLSTEIN COWS IN KUZBASS CONDITIONS

The results of studies of somatic chromosomal instability aneuploidy and polyploidy, the number of fragments and breaks in the blood cells of Holstein cows with a productivity of over 9000 kg are presented. The studies were carried out at JSC “Vaganovo” of the Promyshlennovskiy district of the Kemerovo Region on a population of Holstein cows. Sample preparation was carried out according to the method of P. Moorhead and co-authors, and their staining according to RomanovskyGiemsa. 2452 metaphase plates of cattle blood were studied. The ecological situation was analyzed in the zone of its keeping and breeding. Studies of soil, feed, organs and tissues in farm animals of various species confirm the fact that there are no heavy metal contamination on the territory of Western Siberia and their level is within the limits of sanitary standards. As a result of the study, the frequency of somatic chromosomal instability, including numerical violations and structural aberrations of chromosomes, was established. In the studied sample, the frequency of polyploidy was 0.74%, tetraploidy, triploidy and hexaploidy 0.41; 0.25 and 0.08%, respectively. The frequency of fragments and breaks was approximately the same - 3.83 and 2.91%, respectively. The overall level of chromosome aberrations was 6.75%. The number of diploid cells was 84.25%. Due to the paucity of data on the somatic chromosomal instability of the Holstein breed in Kuzbass conditions, the data obtained can be preliminarily considered as normal values, and also used in assessing the interior of animals.

Особливості клітинного циклу мезенхімальних стовбурових клітин з жирової тканини собаки за різних пасажів культивування

The features of the cell cycle of culture of adipose-derived mesenchymal stem cells from the for different cultivating passages were studied. Mesenchymal stem cells were obtained from the adipose tissue of the dog under a laminar flow hood by an explant method in our modification. Cell cultivation was carried out at 37 °C, 100% moisture and 5% CO2 in Dulbecco’s modified Eagle’s medium (DMEM) containing 10% fetal bovine serum (FBS) and 1% antibiotic-antimycotic. The culture medium was changed 2–3 times per week and the cells were selected by their capacity to attach to the flask surface. When culture flasks became 80% confluence, cells were detached with 0.25% trypsin containing 1 mmol/L EDTA and subsequently replayed at a concentration of 104 cells/cm2 for next passaging. A cells culture of adipose derived mesenchymal stem cells was obtained on the 2nd, 7th and 12th passages. The method of flow cytometry determined the level of aneuploid cells and the distribution in the cell cycle phases. The morphology of cells of different passages was studied using an inverted microscope Axiovert 40. It was investigated that the culture of mesenchymal stem cells from adipose tissue in the 2nd passage contains a significant number of the proliferative pool (S + G2/M) cells and it was 29.51 ± 3.56% of the total number of diploid cells. The number of aneuploid cells was 1.55 ± 0.43%. All cells had fibroblast-like morphology. It was established that in the middle passages (7th) in the culture of mesenchymal stem cells from the adipose tissue of the dog no significant changes were found in the distribution of cells in the phases of the cell cycle. The number of diploid cells of the proliferative pool S + G2/M and the G0/G1 pre-synthetic period remains unchanged. The level of aneuploidy increases only within the tendency. Morphologically, cells had fibroblast-like form. It was determined on 12th passage of cultivation, a significant decrease in the number of cells of the proliferative pool (S+G2/M), which was 18.93 ± 0.66% of the total number of diploid cells compared to the 2nd passage. The number of aneuploid cells increased and it was 3.49 ± 0.38%. Morphologically, separate cells had processes. The indicator of the effect of cells cultivation on the content of diploid cells of the proliferative pool (S+G2/M) in culture is ɳ2x = 70% (P < 0.05). So, first characteristic properties of the aging of the culture of canine adipose-derived mesenchymal stem cells appear on the 12th passage of cultivation.

Shift from polyploidizing to nonpolyploidizing growth in carcinogen-treated rat liver.

Liver growth patterns in normal and carcinogen-treated young Wistar Kyoto rats were analyzed in terms of absolute hepatocyte numbers and ploidy distributions, calculated from DNA measurements made by flow cytometry and microscope counts of binucleated cells. Polyploidizing growth was observed during normal liver development, dominated by progressive polyploidization and a decrease in the number of diploid cells. Nonpolyploidizing growth was seen during liver regeneration and after treatment with 2-acetylaminofluorene (AAF). This mode of growth was characterized by an increase in all mononucleated ploidy classes in the absence of net polyploidization (no increase in binucleated cells). Additional diploid proliferation was detected after initiation with diethylnitrosamine followed by promotion with AAF. This selectively expanding diploid hepatocyte population, which persisted after AAF withdrawal, could represent the AAF-promoted progeny of diethylnitrosamine-altered cells with constitutive nonpolyploidizing growth properties.

A study of the induction of aneuploidy and chromosome aberrations after diazepam, medazepam, midazolam and bromazepam treatment.

Low passage-number cultured Chinese hamster cells were used to assess the ability of four benzodiazepines, namely diazepam, medazepam, midazolam and bromazepam, to induce numerical and structural chromosome aberrations. It was observed that diazepam, medazepam and midazolam treatment produced dose-dependent reductions in the number of diploid cells, with medazepam and midazolam inducing significant levels of hyperdiploidy and diazepam inducing low levels of hypodiploidy (at toxic doses). In contrast, bromazepam-treated cultures showed no significant changes in the level of aneuploidy even when exposed to toxic concentrations. All four sedatives were seen to induce low levels of chromosome aberrations, with bromazepam showing the most potent effect (albeit at a single toxic dose). These observations indicate that these structurally related benzodiazepines could be regarded as potentially genotoxic.

Differences in ploidy and degree of intercellular contact in differentiating and non-differentiating sycamore calluses.

ABSTRACT Comparisons have been made between a sycamore callus (S4) isolated in 1970 and one first isolated in 1958 (S2). Incubation of S4 on media containing different concentrations of auxin and kinetin showed that the ratio of the hormones was the factor which controlled the growth pattern within the tissue. High ratios of auxin: cytokinin favoured a white friable tissue, whereas a compact callus with a much harder texture was formed at low ratios. Roots were differentiated at intermediate values. Callus (S2) has not been induced to undergo cellular differentiation. No soluble factors which were capable of stimulating differentiation in S2 were produced during the differentiation of S4, and S2 did not affect the ability of S4 to form roots. Divisions seen in suspension cultures of S4 callus were mainly diploid; the cells of S2 were predominantly tetrapioid. When S2 suspensions were grown in the cytokinin-free medium used for S4 a considerable number of diploid cells were seen. A number of S2 clones have been isolated and all these developed chloroplasts on exposure to continuous light and, when grown on the medium used to induce differentiation in S4, five of them showed a growth pattern in which the cells were more closely packed than is usually the case in S2 callus. A greater degree of cell contact has also been induced by including polyethylene glycol in the medium and so restricting the availability of water to the callus. Under these conditions the cells must have a greater capacity for interaction with one another. The effect of tissue texture on the extent of cell contact and adhesion between the cells is discussed in relation to the composition of the plant cell wall and ideas on the totipotency of plant tissue cultures.