Ewa Wójcik

Assessment of chromosome instability in geese (Anser anser)

Wójcik, E. and Smalec, E. 2012. Assessment of chromosome instability in geese ( Anser anser ). Can. J. Anim. Sci. 92: 49-57. The basic test applied in the research of chromosome instability is the test of sister chromatid exchange (SCE). It makes it possible to identify single-and double-strand DNA damage caused by genotoxic factors and those that disrupt DNA damage repair mechanisms. Fragile sites in chromosomes can be found in all organisms. They are chromosome sites showing susceptibility to breakages and discontinuities in specific conditions of cell culture and also following induction with chemical substances. Chromosome instability of Anser anser geese was assessed in the research, focussing on sister chromatid exchange and the identification of fragile sites. The mean SCE/cell was 4.75±1.00. Most SCEs were identified in the proximal part of the chromosomes. Fragile sites were also identified in the chromosomes during the research. Altogether, 138 breakages were observed in the chromosomes. Apart from identifying chromosome damage, the particular instances of damage were located in the chromosomes.

Sister chromatid exchange analysis in cats (Felis catus)

Abstract. Sister chromatid exchange (SCE) is one of the cytogenetic methods which diagnoses damage to chromosomes and allows evaluation of the mutagenic influence of a given factor on a cell’s DNA. The purpose of the experiment was to determine the level of spontaneous and inductive SCE in the domestic cat. The research was carried out on 23 domestic cats Felis catus. Chromosome preparations were prepared from lymphocytes of peripheral blood after 72 h of in vitro breeding with the addition of bromodeoxyuridine (BrdU) in five different concentrations: 0.25, 0.5, 1.0, 2.5, 5.0 μg/ml. Chromosomes were stained by means of the fluorescence plus Giemsa (FPG) technique in order to carry out microscopic analysis. It was stated that the level of spontaneous SCE in the domestic cat occurs at a concentration 0.5 μg/ml on the basis of research previously carried out. Higher concentrations of this substance have a genotoxic action and damage DNA of chromosomes and induct additional SCEs in chromosomes of this species. Moreover, it was stated that the number of SCEs is higher in males than females. Our research also proved that the number of exchanges increases along with age in cats of both sexes.

Comparison of different chromatin staining techniques for bull sperm

Abstract. Morphological analysis of semen is a very important step in fertility assessment, but many semen defects are not detectable at the morphological level. These include pathological changes in sperm chromatin structure. During mammalian spermiogenesis, histone proteins associated with DNA structure are replaced by specific protamines, with which chromatin does not form nucleosomal complexes. In the fully developed, mature sperm, the histones are replaced with protamines. Disruptions of nucleoprotein structure can be treated as possible indicators of the biological value of spermatozoa. The experimental material consisted of sperm from one-and-a-half-year-old bulls, isolated post mortem from the tail of the epididymis. The smears were stained with silver nitrate (AgNO3), acridine orange (AO), aniline blue (AB) and chromomycin A3 (CMA3). Sperm dimensions largely depend on individual variability among the bulls. In most cases, differences in sperm dimensions were identified between individuals, which was confirmed in the statistics. Sperm with elevated, abnormal histone levels were proportionally quite scarce (1.4 %). Studies of nuclear proteins in the context of infertility demonstrate the important influence of normal chromatin structure on sperm functions.

Use of Silver Nitrate for the Assessment of Sperm Measurements in Selected Farm and Free-Living Animal Species

Abstract The study was conducted on spermatozoa of selected farm and free-living animal species, isolated post mortem from the tail of the epididymis, and stained with silver nitrate - AgNO3. The material was collected from pigs, goats, wild boar, and European roe deer. Twenty morphologically normal spermatozoa randomly selected from each animal and well visible under the microscope, were analysed. The following measurements were considered: head length, width, perimeter and area, acrosome area, mid-piece length, tail length, and overall sperm length. AgNO3 staining differentiated the acrosomal (light hue) and distal (dark hue) part of the sperm head, and a light-hued mid-piece was visible within the sperm tail. Silver nitrate staining revealed species and variety-related differences, particularly in reference to the sperm head. Clear-cut differentiation within the head and tail area made it possible to perform detailed morphometric measurements of the spermatozoa.

Genome size of the European domestic goose (Anser anser domesticus).

This work is aimed at determining the C-DNA contained within the nuclei of different types of cells in the domestic goose Anser anser. Cells from the lungs, skin, pancreas, kidney, spleen, liver, heart, brain, blood, ovary and testicle were analysed. Cells from the blood, ovary and testicle were smeared onto microscopic glasses, whereas slides from the other organs and tissues were prepared using the paraffin technique. DNA content, as visualized by the Feulgen reaction using computerized image analysis, was examined in 200 nuclei of every type of cell. Chicken erythrocytes were used as reference material. Different concentrations of chromatin within cell nuclei were observed, from small, dispersed clods to an entirely filled nucleus surface. It was stated that the average C-DNA content in the domestic European goose amounts to 1.306 ± 0.327 pg, which gives goose DNA a length in base pair of 1.277 × 109 ± 0.320 × 109 bp after adjustment. The correlation between nucleus size and the C-DNA content was posit...

Description of the mallard duck (Anas platyrhynchos) karyotype.

The karyotype of the mallard duck, Anas platyrhynchos, was characterised on the basis of R and C bands. Chromosomal preparations obtained from in vitro blood lymphocyte cultures were RBG- and CBG-stained. The structures of nine and 14 pairs of chromosomes were analysed by the RBG and CBG chromosome banding techniques, respectively. The location of R bands, as well as the size and arrangement of constitutive heterochromatin blocks were determined. Ideograms of R and C banded patterns of the analysed chromosomes were drawn. The morphological makeup of the analysed chromosomes was assessed.

Spontaneous sister chromatid exchange in mitotic chromosomes of the chinchilla (Chinchilla lanigera)

Kuchta-Gladysz, M., Wójcik, E., Szeleszczuk, O., Niedbala, P. and Tyblewska, K. 2015. Spontaneous sister chromatid exchange in mitotic chromosomes of the chinchilla (Chinchilla lanigera). Can. J. Anim. Sci. 95: 543-550. The sister chromatid exchange (SCE) test is a cytogenetic tool with applications as a short-term screen. It is used to assess the influence of physical and chemical factors with potential mutagenic and genotoxic properties on the animal organism. The test results make it possible to eliminate mutagens, as well as helping to predict possible genetic consequences in animal cells and assess animal resistance. The mitotic chromosomes were obtained from an in vitro culture of peripheral blood lymphocytes with added bromodeoxyuridine (BrdU), at five different concentrations: 0.25, 0.5, 1.0, 2.5, and 5.0 µg mL-1. The chromosomes were stained according to the FPG method. Our analyses revealed the spontaneous SCE level in the chinchilla at the concentration of 0.5 µg mL-1. Higher concentrations of this substance have a genotoxic effect and cause damage to the DNA structure of the chromosomes by inducing additional SCEs in the chromosomes of this species. The mean SCE/cell incidence in the chinchilla population was 4.34±1.28. We investigated the effects of age on the incidence of SCE and found it significantly affected this phenomenon in both sexes.