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Introduction Bees are currently artificially inseminated on a large scale for breeding and research purposes. The sperm of bees has a complex and varied structure, and determination of specific morphological defects in it is very difficult. Its comprehensive analysis by inspecting morphology and morphometry is an important tool for improving honey bee lines. The staining technique should interfere with the cells as little as possible while clearly showing the boundaries of the head and other elements. In this study, a comparative analysis of the morphometry of sperm was performed with various techniques for staining drone semen. Material and Methods Semen was collected from 150 sexually mature Buckfast bee drones by artificially everting the copulatory organ. The morphology and morphometry of the sperm were assessed on slides prepared by three staining methods according to the protocols described online, using the Sperm Class Analyzer system. The lengths of the acrosome, nucleus, head in total, midpiece, tail without midpiece, tail with midpiece, and entire sperm were measured. Results The most details of the drone sperm structure could be seen when stained with the eosin-nigrosin complex. This method made it possible to identify all structures and revealed the uneven distribution of sperm proteins in different parts of the tail. With the Sperm Stain method fewer details of the sperm structure were recognisable, and the fewest were with SpermBlue. Conclusion The staining method, and thus the chemical reagents used, affect the dimensions of drone sperm. Given the great research potential of modified spermatozoa of insects, a standard for slide preparation for the evaluation of morphological and morphometric semen parameters should be established, as this would facilitate result comparison between laboratories and increase the value of morphological analysis of sperm for predicting and assessing fertility.

The aim of the study was to determine the effect of Cu and Zn chelates on the levels of these microelements in the blood of broiler chickens in successive weeks of rearing. The re-search material was Ross 308 broiler chickens. The study was carried out in two buildings with 30,000 chickens in each. From each building, 50 chickens were randomly selected to form the experimental and control groups. Blood for analysis was collected from the wing vein every 7 days, from the first day of fattening to day 42. In the experimental group the microelements zinc and copper contained in the feed were in organic form. The effect of the feed additive containing selected microelements in organic form on broiler chickens was assessed from weeks 1 to 6 of fattening. During the experiment the average body weight gains were monitored. Mortality was monitored, and feed consumption per kg weight gain was estimated. To conclude, the addition of organic Cu and Zn chelates to the diet of broiler chickens affected their average body weight gain, increasing body weight at the start and end of the fattening period (fifth and sixth weeks of age) while increasing feed conversion.

Folic acid has multi-faceted effects on the body. Its biological activity ensures genome stability and the normal course of the cell cycle. A deficiency of this acid can lead to serious consequences for health and life. Folic acid is the most oxidized form of folates taken with food. Folic acid is not produced in horses and must be ingested with food. Its bioavailability is also affected by environmental factors. The aim of the study was to analyse the content of folic acid in the blood serum of Polish Konik horses kept in a free-roaming herd system and a stable system. The folic acid concentrations in all horses were within the normal range of reference values for the species. Higher folic acid concentrations were noted in the free-roaming horses. Variation in the content of folic acid in the serum of stabled horses was higher than in the free-roaming horses. The management system was not found to significantly affect the serum content of folic acid in the horses.

Introduction The Dag defect is one of the primary morphological defects in sperm correlating with reduced fertility. This defect is found in the spermatozoa of many livestock species. The aim of the study was to assess the morphometry of the heads of normal sperm and sperm with the Dag defect in the semen of Duroc breeding boars. Material and Methods Sperm morphology was examined in ten ejaculates each from 12 Duroc boars. In total, 3,600 morphologically normal sperm and 838 sperm with the Dag defect were evaluated. The area, perimeter, length and width of the sperm head were measured and these basic morphometric parameters were used to calculate four additional shape indices characterising the sperm head, i.e. ellipticity, elongation, roughness and regularity. Results Sperm with this defect had markedly smaller heads, 0.32 μm shorter and 0.19 μm narrower than the heads of sperm with normal morphological structure. The heads of sperm with the Dag defect also had a 1.1μm smaller perimeter and a 2.5 μm2 smaller surface area than the heads of morphologically normal sperm. Conclusions The Dag defect is found in boar sperm irrespective of the age of the individual. It affects the morphology of the sperm head.

Sperm cells isolated from the tail of the epididymis and from the semen of the same individuals were analysed. The use of silver nitrate to stain sperm cells isolated from the tail of the epididymis made it possible to identify structures that were not visible in the sperm from semen. Silver nitrate very clearly distinguished the acrosomal and distal parts of the sperm head. Following silver nitrate staining, the sperm isolated from the tail of the epididymis were characterized by dark 'collars' in the distal part of the head. These 'collars' are not visible in the sperm cells isolated from semen. The results of the study indicate differences in the dimensions of sperm isolated from the tail of the epididymis and sperm in semen. Sperm isolated from the tail of the epididymis had smaller heads, despite their longer length, and had longer midpieces and tails than ejaculate sperm. Silver nitrate staining is a simple and fast technique. Silver nitrate makes it possible to identify the acrosome and post-acrosomal region of the sperm head and to clearly identify the midpiece. Therefore, it can be successfully used to supplement routine techniques for evaluating sperm morphology or as an independent technique.

Routine evaluation of the sperm of livestock animals involves detection of morphological abnormalities. However, most sperm defects that reduce fertilizing capacity are a result of anomalies in spermatogenesis. The aim of the study was to evaluate the effect of a boar's age on the stability of the genetic material of its sperm. The age of the boar was found to have a significant effect on sperm DNA stability and chromatin structure. The highest percentage of spermatozoa with DNA fragmentation was found in the oldest group of boars (0,61%), while the highest proportion of spermatozoa with abnormal histone retention (8,01%) and protamination (9,78%) was found in the youngest group of boars. Aniline blue (AB), chromomycin A3 (CMA3) and acridine orange (AO) staining should be routinely used in individuals used for artificial insemination especially young animals at the start of their exploitation for breeding, as well as older individuals with an age-related decrease in the stability of genetic material. Earlier diagnosis based on additional tests would allow for stricter selection and elimination of males with fertility disorders from breeding, to be replaced by breeders of full value. It was also demonstrated that all three staining methods mentioned above can be used in classical morphological analysis, because they clearly distinguish the sperm head from the background of the slide. Chromomycin staining clearly reveals the midpiece and thus can be used as a specific staining method for its evaluation. Staining with aniline blue is a fast and simple test whose result can be analysed under a light microscope. This staining technique can be recommended for use at insemination stations.

Recent years have seen increased interest in the influence of bioactive dietary components on human genes and gene expression. A good source of many bioactive substances is the chicken egg. The egg is considered to be an excellent food provided by nature. It is a good source of nutrients such as vitamins A, B2, B6, B12, D, E and K, as well as elements including phosphorus, selenium, iron, zinc, magnesium and calcium. The research material use in this study consisted of eggs from hens kept in two different systems: organic and battery cages. The content of calcium (Ca), magnesium (Mg) and zinc (Zn) was determined in the egg contents – in the yolk and white respectively. The content of elements was determined by atomic absorption spectrometry (AAS) using an AA280 FS spectrometer with the automatic dilution of standards and samples. The eggs from the organically raised hens had a higher calcium, magnesium and zinc content. The greater variation in the Ca, Mg and Zn content in the organic eggs is due to the more individualized feeding system. The rearing system of the hens significantly affects the concentration of elements in the egg. The results of this research indicate that eggs from organic farming systems have a richer chemical composition in terms of the content of nutrients such as calcium, magnesium and zinc compared with eggs obtained from caged hens. Therefore, consumers purchasing eggs should consider the system in which the hens were reared, as eggs can be a valuable source of these elements in the diet.

The aim of the present study was to determine the frequency of different allergies in horses from central Poland. Allergic diseases are common in horses all over the world. Common conditions that have been associated with immunoglobulin E (IgE)-mediated allergy in horses include insect bite hypersensitivity (IBH), urticaria and recurrent airway obstruction (RAO). A variety of serological assays are available to measure serum levels of allergen-specific IgE antibodies. They can provide supportive evidence for a diagnosis of equine allergic dermatitis associated with environmental allergens. This study was performed on clinically healthy, Polish noble half-breed horses. In this study, four groups of allergens were identified as commonly inducing allergic reactions: American house dust mites (D. farinae), cultivated plants (rape), English plantain (Plantago lanceolata) and biting midges (Culicoides nubeculosus). More than 50% of horses showed positive reactions to these groups of allergens. The factor that contributed most to allergy occurrence among horses was American house dust mites (D. farinae). In recent years, efforts have been made to identify new allergens and to better understand the specific pathogenesis of allergic diseases in animals. The development of allergic disease diagnostics has been facilitated by the availability of diagnostic methods along with enhanced awareness of allergic diseases in veterinary practice. Allergic disorders in horses are ultimately gaining the attention they deserve thanks to the fact that veterinary allergology has become a dedicated veterinary discipline., Cilj ove studije bio je ustvrditi učestalost različitih vrsta alergija u konja iz središnje Poljske. Alergijske bolesti su učestale u konja diljem svijeta. Uobičajena stanja koja su povezana s alergijskom reakcijom posredovanom imunoglobulinom E (IgE) u konja uključuju preosjetljivost na ubode insekata (IBH), urtikariju i povratnu opstrukciju dišnih putova (RAO). Dostupni su različiti serološki testovi za mjerenje razina specifičnog IgE antitijela na alergene u krvi. Oni mogu osigurati potkrepljujuće dokaze za dijagnozu alergijskog dermatitisa konja s alergenima iz okoliša. Ova studija provedena je na poljskim plemenitim, klinički zdravim, križanim pasmina konja. U ovoj studiji identificirane su četiri skupine alergena koje obično prouzroče alergijske reakcije: američke grinje iz kućne prašine (D. farinae), kultivirane biljke (repica), uskolisni trputac (Plantago lanceolata) i mušice (Culicoides nubeculosus). Više od 50 % konja pokazalo je pozitivne reakcije na ove skupine alergena. Čimbenik koji je najviše pridonio pojavnosti alergijskih reakcija među konjima bile su američke grinje iz kućne prašine (D. farinae). U posljednjih nekoliko godina, pojačanje napora u suzbijanju alergijskih bolesti dovelo je do identifikacije nekih novih alergena, kao i dubljeg razumijevanja patogeneze životinja specifične za alergijske bolesti. Razvoj u dijagnozi alergijskih bolesti olakšan je dostupnošću dijagnostičkih metoda uz povećanu svijest o alergijskim bolestima u veterinarskoj praksi. Alergijski poremećaji u konja konačno dobivaju pozornost koju zaslužuju zahvaljujući činjenici da je alergologija postala značajna specijalizirana veterinarska disciplina.

Sperm morphology and morphometry are considered parameters in fertility diagnosis. They are especially important in the case of species for which there is no standard with respect to morphometric sperm parameters. It is then crucial to apply the staining technique that has the least influence on the sperm structure and provides the most detailed image, so as to enable measurements. The aim of the research was to assess the morphometric parameters of rabbit sperm using silver nitrate staining. The staining process revealed a detailed image of the spermatozoon head and tail, thus enabling precise measurements. From these basic morphometric parameters, four additional shape indices characterizing the sperm head were calculated: ellipticity, elongation, roughness and regularity. These parameters more precisely characterize the shape of the sperm head. Silver nitrate staining can be used as an independent technique in assessment of sperm structure or to supplement routine diagnostics.

Many of the methods used to stain semen result in very pronounced coloring of the sperm, but unfortunately they do not distinguish their individual structures, which play a key role in the fertilization process. Hence the aim of this study was to identify sperm structures using two staining techniques in the semen of roosters from breeding flocks. The subject of the study was the sperm of roosters from a Ross 308 breeding flock. To capture the differences in the dimensions of sperm subjected to the effect of different chemical substances in dyes, microscope slides were stained by two techniques: with an AgNO3 solution and by a differential method (eosin-nigrosin test). Assessment was made of the degree of coloration and the number of details that could be identified in the morphological structure of the sperm. The use of AgNO3 allowed accurate identification of the acrosome, nucleus, and midpiece, which were visible in the slides stained with eosin-nigrosin, but only in dead spermatozoa. The AGNO3 staining technique used in this study reveals the cell nucleus within the head and can be an alternative method to analysis with a scanning electron microscope. This staining technique can be used to stain sperm structures that cannot be seen in other methods of slide preparation, which means that it can be considered for routine use in assessing the fertility of roosters in breeder flocks.

Electrophoretic techniques, used to separate mixtures of electrically charged particles, are widely used in science. One of these techniques, native protein electrophoresis in an agarose gel, is applied in human and veterinary medicine. Changes in the proportions of individual protein fractions correspond to significant changes in the physiology of the body. Although the pattern obtained by electrophoretic separation rarely indicates a specific disease, it provides valuable information for the differential diagnosis. Decades of research on the types of patterns obtained in the case of particular diseases have led to the accumulation of substantial knowledge. The paper presents the available information on this topic. Serum protein electrophoresis is recommended in cases of increased levels of total protein in order to reveal the nature of the process. The basic information which can be obtained from electrophoretic separation includes the immune status of the organism. Both increased antigenic stimulation and immunodeficiency are clearly visible in electropherograms. Moreover, the level of heterogeneity of the corresponding protein fractions can help to distinguish between infectious diseases and cancer - multiple myeloma - the latter producing a homogeneous immunoglobulin fraction. Analysis of other protein fractions helps to detect or confirm an ongoing inflammatory process and provides information regarding liver function. Even when the concentration of total protein is within the reference range, this analysis can be recommended as a basic laboratory test.

The aim of the study was to determine the number and shape of nucleoli during meiosis in cells of the domestic horse. In addition, the level of global DNA methylation was determined using a quantitative technique for measuring the relative level of DNA methylation, modelled on an immunoenzymatic assay. The research was carried out on stallions belonging to two age groups (2 and 7 yr). In the cells of the 2-yr-old animals, the nucleoli were mainly of a regular shape and no fragmented nucleoli were observed. The cells of the 7-yr-old horses had a small percentage of regularly shaped nucleoli, and nucleoli with a fragmented structure were present. The study provides a basis for further research on epigenetic mechanisms in horses.

The results presented in this study are the first such extensive characterization of the sperm morphometry of the blue fox (Alopex lagopus) and silver fox (Vulpes vulpes), as representatives of the family Canidae. Canine spermatozoa, especially the sperm of farmed foxes, are not often described in studies on reproduction. The aim of the study was a detailed comparison of the morphometric dimensions and shape of the sperm of two fox species: silver fox and blue fox. Semen collected from 10 silver foxes and 10 blue foxes was used for the study. The specimens were stained with silver nitrate. Measurements were performed of the length, width, perimeter, and area of the head, the area of the acrosome and its coverage, the length of the midpiece and its coverage, the length of the tail, and the length of the end piece of the tail. In addition, four head shape indices were calculated: ellipticity, elongation, roughness and regularity. The following values for the morphometric parameters and shape indices were obtained for blue fox and silver fox, respectively: head length&mdash, 6.72 &micro, m and 6.33 &micro, m, head width&mdash, 4.54.&micro, m and 4.21 &micro, head perimeter&mdash, 18.11 &micro, m and 17.37 &micro, head area&mdash, 21.94 &micro, m2 and 21.11 &micro, m2, acrosome area&mdash, 11.50 &micro, m2 and 10.92 &micro, midpiece length&mdash, 12.85 &micro, m and 12.79 &micro, tail end piece length&mdash, 3.44 &micro, m and 3.28 &micro, tail length&mdash, 65.23 &micro, m and 65.09 &micro, acrosome coverage&mdash, 52.43% and 52.83%, midpiece coverage&mdash, 19.71% and 19.65%, sperm length&mdash, 71.95 &micro, m and 71.42 &micro, ellipticity&mdash, 1.49 and 1.52, elongation&mdash, 0.19 and 0.20, roughness&mdash, 0.84 and 1.88, regularity&mdash, 1.09 and 0.99. The significance of differences between species was verified by Tukey&rsquo, s test at p &le, 0.05. Statistically significant differences between species were found for the following parameters: head length, width, perimeter and area, acrosome area, tail, end piece, and total sperm length, roughness and regularity. The differences in the size and shape of sperm can be used to establish reference patterns for fox sperm enabling more accurate species identification.

Allergies in dogs have become a relatively frequent topic of discussion in veterinary surgeries. Many dogs, both purebred and of mixed breeds, are diagnosed for allergies. Allergies have many causes, from genetic predisposition to the environmental conditions in which the animal lives. Allergies in dogs are troublesome because they can lead to serious health complications when diagnosed late or left untreated. The results of the study support the hypothesis that the percentage of allergies to individual allergens varied by region (Tab. 4). Differences were observed in the case of Dermatophagoides pteronyssinus and Dermatophagoides farinae house dust mites, Acarus siro, and Tyrophagus. The remaining allergens caused allergic reactions in similar percentages of dogs from northern, central and southern Poland.

The latest reports indicate that sperm function is significantly influenced by the chromatin structure of the sperm and the integrity of its DNA. The aim of the study was to determine the level of condensation in the chromatin structure of fresh semen and the degree of damage to the DNA chain in fresh and chilled semen of farmed blue and silver foxes. The sperm of 15 blue foxes and 18 silver foxes at the age of one year was used in the study. The chromatin structure was evaluated by three staining techniques: aniline blue, chromomycin A3 and acridine orange. A comet assay was used to assess sperm DNA integrity in fresh and chilled semen. The average percentage of head DNA changed over time: in blue foxes from 99.12% to 97.83%, and in silver foxes from 99.37% to 98.05%. Highly significant differences (P

Lampbrush chromosomes (LBCs) represent a new model in avian cytogenetics and are increasingly more often used in poultry chromosome analyses. Additionally, lampbrush chromosomes are considered as model structures in the study of transcription regulation. Changes in transcription activity are reflected as modifications of LBC morphological structure and associated with physiological processes in the organism. The aim of the present study was to compare transcriptional activity of the first five lampbrush macrochromosomes and ZW sex lampbrush bivalents sampled from the oocytes of geese prior to and after the reproductive period. The respective bivalents sampled before and after reproduction have similar sizes but differ in morphological structure. Side loops of lampbrush chromosomes are sites of transcription activity. The activity varies according to the loop size. As the loops become more prominent, the activity grows and vice versa. Lampbrush chromosomes sampled after reproduction have smaller side loops. On the other hand, inactive chromomeres become prominent in the chromosomes. Marker loops are the last structures to be degraded after the end of reproduction. Consequently, they are used for identifying particular bivalents at different stages of cellular transcriptional activity.

Nucleoli are the product of the activity of nucleolar organizer regions (NOR) in certain chromosomes. Their main functions are the formation of ribosomal subunits from ribosomal protein molecules and the transcription of genes encoding rRNA. Nucleoli are present in the nuclei of nearly all eukaryotic cells because they contain housekeeping genes. The size and number of nucleoli gradually decrease during spermatogenesis. Some of the material originating in the nucleolus probably migrates to the cytoplasm and takes part in the formation of chromatoid bodies (CB). Nucleolus fragmentation and CB assembly take place at the same stage of spermatogenesis. CB are involved in the formation of the acrosome, the migration of mitochondria to the midpiece, and the formation of the sperm tail fibrous sheath. The aim of the study was to characterize the nucleoli in the early prophase of spermatogenesis in the wild boar and the roe deer. The roe deer cells have larger nucleoli and a larger cell nucleus than the wild boar cells. The area of the nucleolus as a percentage of the total area of the nucleus was larger as well. The coefficients of variation for all parameters were higher in the roe deer. In the wild boar cells the nucleoli were mainly regularly shaped. The size of the nucleolus and the nucleus of the spermatocyte is a species-specific trait associated with karyotype and the number of nucleolar organizer regions in a given species.

Sperm morphometry has some value as an indicator of reproductive capacity in males. In laboratory practice a variety of slide-staining methods are used during morphological evaluation of semen to predict male fertility. The aim of this study was to determine the effect of staining of semen using four different techniques on the morphometry of the bull sperm cell. The material for the study consisted of semen collected from test bulls of the Black-and-White variety of Holstein-Friesians. The results obtained in the study indicate differences in the dimensions of bull sperm heads when different slide staining techniques were used. The most similar results for sperm head dimensions were obtained in the case of SpermBlue(®) and eosin+gentian violet complex, although statistically significant differences were found between all the staining techniques. Extreme values were noted for the other staining techniques - lowest for the Papanicolaou and highest for silver nitrate, which may indicate more interference in the cell by the reagents used in the staining process. However, silver nitrate staining was best at identifying the structures of the sperm cell. Hence it is difficult to determine which of the staining methods most faithfully reveals the dimensions and shape of the bull sperm.

This study was an attempt to evaluate sperm chromatin structure in the semen of insemination boars. Preparations ofsemen were stained with acridine orange, aniline blue, and chromomycin A3. Abnormal protamination occurred more frequentlyin young individuals whose sexual development was not yet complete, but may also be an individual trait. This possibilityis important to factor into the decision regarding further exploitation of insemination boars. Thus a precise assessmentof abnormalities in the protamination process would seem to be expedient as a tool supplementing morphological andmolecular evaluation of semen. Disruptions in nucleoprotein structure can be treated as indicators of the biological value ofsperm cells. Keywords: boar, sperm, protamine, histone. Introduction Evaluation of semen is a basic tool in thediagnosis of male fertility. However, routinelyperformed tests of basic semen parameters appear tobe insufficient to determine fertility. This takes ongreater importance in the case of breeders used atinsemination centres. The costs of purchasing andkeeping selected males are not always commensuratewith the quality of the semen obtained from them andits fertilisation capacity. Hence it would be worthexpanding preliminary semen diagnostics to includeadditional tests, at least at the start of a breeder’sexploitation. A lack of success in fertilisation mayhave deeper causes (23). Some authors suggest that inaddition to standard semen analysis, functional testsshould be used as well, as the fertilisation ratedepends to a large extent on the quality of the semenused for insemination (10, 26). Research on theintegrity of boar sperm DNA has been conducted byFraser and Strzezek (16), Perez-Llano (29), andHu

Semen was collected from Polish Halfbred stallions. Twenty individuals from 3 to 4 years of age were selected for the study. At least one ejaculate from each stallion was collected and assessed. Sperm morphology was evaluated using Papanicolaou stain, SpermBlue®, and a complex of eosin and gentian stain, whereas unstained slides were used as control samples. Morphometric measurements were performed on 100 randomly selected sperm heads in each ejaculate. The length, width, perimeter, and surface area of the sperm head were measured. The frequency of nuclear vacuoles was determined as well. Tygerberg’s strict criteria, which most precisely characterise the sperm head, were used in the morphological evaluation of the sperm. The results obtained indicate that in the case of staining with SpermBlue® and with eosin+gentian complex, the morphometry of the sperm head seems to be most similar to that observed in unstained smears. It also seems that neither shrinking nor swelling is uniform in the various staining techniques (Papanicolaou stain). Moreover, it appears that in comparison with unstained sperm, all methods caused the width of the head to increase as a result of swelling.

A problem in evaluating the morphology and morphometry of sperm is the lack of standardization of staining techniques. The method of staining and evaluating specimens can significantly affect the results of morphometric measurements. The aim of the study was to determine the effect of two techniques for staining stallion sperm on the morphology and morphometric dimensions of sperm cells and the formation of artefacts. The subject of the study was the sperm of Polish Half Bred stallions, isolated post mortem from the tail of the epididymis. Morphometric measurements were made of the following: length, width, perimeter and surface area of the sperm head, surface area of the acrosome, midpiece length, tail length and total sperm length. Sperm evaluation was expanded to include acrosome coverage, i.e. the surface area of the acrosome as a percentage of the total area of the sperm head, and a characterization of the tail, particularly the midpiece. Tygerberg strict criteria were used to evaluate sperm morphology. The data show that the staining method and the chemical reagents applied have a substantial effect on the dimensions and shape of the stallion sperm. The literature on the subject draws attention to the fact that a staining technique should be established or developed which would enable precise and unambiguous analysis of the morphology and morphometry of human and animal spermatozoa. Moreover, a standard should be developed for preparing specimens for morphological analysis. This would enable comparison of results between laboratories, thus enhancing the value of morphological analyses of sperm in predicting and evaluating fertility.

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.

Lampbrush chromosomes (LBCs) represent a new model in avian cytogenetics and are increasingly more often used in poultry chromosome analyses. Additionally, lampbrush chromosomes are considered as model structures in the study of transcription regulation. Changes in transcription activity are reflected as modifications of LBC morphological structure and associated with physiological processes in the organism. The aim of the present study was to compare transcriptional activity of the first five lampbrush macrochromosomes and ZW sex lampbrush bivalents sampled from the oocytes of geese prior to and after the reproductive period. The respective bivalents sampled before and after reproduction have similar sizes but differ in morphological structure. Side loops of lampbrush chromosomes are sites of transcription activity. The activity varies according to the loop size. As the loops become more prominent, the activity grows and vice versa. Lampbrush chromosomes sampled after reproduction have smaller side loops. On the other hand, inactive chromomeres become prominent in the chromosomes. Marker loops are the last structures to be degraded after the end of reproduction. Consequently, they are used for identifying particular bivalents at different stages of cellular transcriptional activity.

The work was aimed at determining the number and morphology of nucleoli in the prophase of the first meiotic division in domestic cattle males. The use of AgNO3 staining, commonly applied in cytogenetics for the identification of nucleolar organiser regions, made it possible to identify nucleoli in first-order spermatocytes. One nucleolus was identified in each analysed cell. Considerable morphological differentiation of the nucleoli during the prophase of the first meiotic division, particularly in leptotene, unobserved in other farm animal species, was noticed. Dark-hued grain-like structures were found within the disintegrating nucleoli, corresponding approximately or exactly to the number of the nucleolar organiser regions in the domestic cattle karyotype. Dark areas were identified in the selected prometaphase chromosomes. Their number corresponded with the number of active NORs defined in the domestic cattle karyotype.

A basic assay that detects genotoxic DNA damage disrupting DNA replication and repair mechanisms is the sister chromatid exchange test. The frequency of sister chromatid exchanges was analyzed in chromosomes of the following hen breeds: Greenleg Partridge and Polbar. Chromosome preparations were obtained from our in vitro culture of peripheral blood lymphocytes stained using the fluorescence plus Giemsa (FPG) technique. The sister chromatid exchange (SCE)/cell mean of the hens under analysis was 7.83 ± 1.76 (7.22 ± 1.70 in the Greenleg Partridge and 8.43 ± 1.61 in the Polbar population). Statistically significant differences were identified between the hen breeds. A higher mean number of SCE/cell was observed in the group of hens producing fewer eggs (8.55 ± 1.51) compared with the group with a better egg yield (7.10 ± 1.65). The differences were statistically significant. Additionally, SCE frequency in the first, second, and third chromosome was analyzed in detail. The highest number of SCE was observed in the first and the lowest in the third chromosome. The SCE distribution in the particular regions of the analyzed chromosomes was also studied. The most numerous exchanges were observed in the proximal region, followed by the interstitial and distal areas.

Nucleoli are the product of nucleolus organizing region activity (NOR) of specific chromosomes. Their basic function is to synthetise ribosomal RNA precursors and promote the maturation and assemblage of preribosomal RNP molecules. Information on rRNA-coding gene activity can be provided by the analysis of the number and size of nucleoli in the prophase of the first meiotic division. The morphology and ultrastructure of a nucleolus depends, among others, on the species and cell growth cycle as well as the physiological and pathological state of an organism. The purpose of this research was to determine the number and size of nucleoli in the spermatocytes of the domestic chicken and the Japanese quail. Diverse numbers and sizes of nucleoli in the cells of the analysed birds were observed. 1-4 nucleoli were identified in chicken cells (1.91 +/- 0.63 on average) and 1-2 in quail cells (1.13 +/- 0.33 on average). For the total of 957 nucleoli observed in Gallus cells, 329 were classified as large and 628 as small. In Coturnix cells, 563 nucleoli were identified (66 large and 497 small ones). An analysis of the numbers and sizes of nucleoli can be performed at the cytogenetic level and serve as an alternative source of information on rRNA encoding gene and nucleolus organising region (NOR) activities.

Andraszek, K. and Smalec, E. 2011. The use of silver nitrate for the identification of spermatozoon structure in selected mammals. Can. J. Anim. Sci. 91: 239–246. The spermatozoon is one of the most diversified cell types, and the chromatin of the haploid spermatozoon genome is essentially different from that of the somatic cell as regards its chemical composition, structure and function. Although the structure of spermatozoon chromatin has crucial importance for fertilization and embryo development, standard staining techniques are still predominantly used for identifying semen quality and the assessment of spermatozoa is most often limited to detecting irregularities in their morphological structure. The aim of the present research was to evaluate the usefulness of silver nitrate staining for assessing spermatozoon morphology and identifying spermatozoon structure. Spermatozoa isolated from testes and semen were examined. Silver nitrate staining made it possible to identify many significant details of the morphological structure of the spermatozoon and could be successfully employed in sperm morphology assessments.

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 positive and high. In all cell types it exceeded 0.6. The highest was observed in lung and ovary cells, the lowest in skin and the pancreas. The majority of all cells (57.34%) contain DNA at the range between 1.0 to 1.5 pg, especially those from erythrocytes and the pancreas (82 and 76% respectively). Liver cells demonstrate a tendency toward an amount that is higher than 1.5% of the DNA (78.61% cells). Heart cells reveal a tendency downward (98.99% below 1.5 pg). Less than 1.0 pg of DNA was observed in 17.13% of all examined cells. Key words: Domestic goose, cell, cell nuclei, Feulgen reaction, genome size, DNA mass

The Polish White Improved goat karyotype consists of 29 pairs of acrocentric autosomes, a large acrocentric X chromosome and a metacentric Y chromosome which is the smallest in the karyotype. Staining of chromosomes with AgNO,sub>3 solution has revealed active nucleolar organizer regions (NOR) in terminal parts of q arms of pair 2, 3, 4, 5, and 28 chromosomes. Out of the total of 100 analysed cells 736 active NORs have been found, on average 7.4±0.2 per cell. Active NORs were most frequently observed in pair 2, and 3 chromosomes, most rarely on pair 5 chromosomes. In all the analysed cells 141, satellite associations (SA) were observed, on average 1.4±0.2 per cell. SAs most often occurred in cells with seven active NORs, and least often in cells with three or four nucleolar organizer regions. Most frequently in SAs the presence of pair 2, 3 and 28 chromosomes was observed. On meiotic chromosomes staining with AgNO3 solution revealed two nucleoli stained with different intensity. Both nucleoli in the cell were of similar size.

The synaptonemal complex (SC) is a protein structure which binds two homologues during prophase of the first meiotic division and assures the correct course of genetic recombination. The demonstration and identification of SCs in European domestic goose Anser anser was the aim of the current research. Standard techniques of SC identification do not allow for an analysis of their molecular structure. In meiotic cells of one-day-old nestlings and 17-week-old geese the haploid number of bivalents, darkly stained kinetochores and subtelomeric regions may be evidence for the presence of SCs. Experimental chromosome staining with the DAPI fluorochrome permitted the observation of the characteristic ladder-like structure of SCs and the course of synapsis formation within homologues from early leptotene to their degradation in late pachytene. The detailed molecular structure of synaptonemal complexes can be analysed with an electron or scanning microscope only. Because the bivalent is a direct result of the complex's presence, in the literature the presence of bivalents is equivalent to the term "synaptonemal complex". However, the bivalent and the SC are two different structures.

In this study an attempt was made to analyse morphological changes in sperm with particular attention to sperm with a cytoplasmic droplet, taking into account the age and breed of the boar. The material for the study consisted of ejaculates of insemination boars of five breeds. Morphological examination of sperm was carried out in 30 randomly selected boars--6 individuals from each breed. The morphology of 500 spermatozoa was evaluated in each slide. The percentage of sperm with normal morphology in the semen of the boars varied between breeds and was dependent in varying degrees on the age of the boar. The primary defects in sperm occurred more frequently in Duroc and Pietrain boars than in other breeds and were more dependent on the age of the boar. The high percentage of primary defects in the sperm of young Duroc boars was determined by the frequency of sperm cells with a proximal cytoplasmic droplet on the midpiece. A particularly high percentage of sperm cells with secondary defects was noted in the initial stage of the reproductive life of the boars. The high number of sperm cells with secondary defects noted in the semen of the Duroc and Pietrain boars and the changes occurring with age in the frequency of secondary morphological defects were mainly determined by the frequency of sperm cells with a distal protoplasmic droplet in the middle piece and to a lesser degree by that of sperm cells with a pseudodroplet.

Nucleoli are the product of the activity of nucleolar organizer regions (NOR) in certain chromosomes. Their main functions are the formation of ribosomal subunits from ribosomal protein molecules and the transcription of genes encoding rRNA. The aim of the study was to determine the shape of nucleoli and analyse methylation in the gene RN28S in the spermatocytes of male Japanese quail (Coturnixjaponica) in two age groups. Nucleoli were analysed in cells of the first meiotic prophase. Their number and shape were determined and they were classified as regular, irregular or defragmented. In the cells of the young birds no defragmented nucleoli were observed, with regular and irregular nucleoli accounting for 97% and 3%, respectively. In the cells of older birds no regular nucleoli were observed, while irregular and defragmented nucleoli accounted for 37% and 67%, respectively. MSP (methylation-specific PCR) showed that the gene RN28S is methylated in both 15-week-old and 52-week-old quails. In recent years an association has been established between nucleolus morphology and cellular ageing processes.

DNA methylation is an epigenetic modification that plays an important role in the proper development and functioning of an organism. The DNA methylation level is species-, tissue- and organelle-specific, and the methylation pattern is determined during embryogenesis. A correlation between methylation and age is also observed. Epigenetic phenomena are an enormously interesting research subject, not only from the perspective of pure science, but also due to their possible applications in medicine. The aim of this study was to determine the global DNA methylation level in relation to the developmental stage of the embryo. The global level of 5-methylcytosine in the DNA during pulmonary respiration was found to be higher than during allantoic respiration. The analysis shows a clear dependence between the stage of individual development and the global DNA level of 5-methylcytosine. In the future, methylation level may be a determinant of age and perhaps even a tool for predicting life expectancy. Abnormalities in the methylation process result in premature ageing at the cellular and individual level.

The basic method for analyzing the degree of DNA fragmentation caused by genotoxic factors is gel electrophoresis of single cells (single cell gel electrophoresis), also called the comet assay. The comet assay enables the analysis of the level of several different DNA modifications. The basic testing procedure has been only slightly modified. This method helps identify single-strand and double-strand DNA cracks, as well as any chemical and enzymatic modifications that can potentially turn into cracks in DNA or chromatids. The comet assay makes it possible to detect DNA damage at the level of single cells. It can be employed in analyses of any tissues which provide cellular suspensions. Analysed cells are submerged in agarose on a microscope slide. DNA is what is left after proteins have been broken down. The slide is then subjected to electrophoresis and stained with a fluorescent dye. A “comet-like” image is obtained. The “head” is the cell fixation site prior to lysis; the “tail” represents damaged DNA fragments. The extent of DNA damage is reflected in the length of the tail and the amount of DNA contained in it. The assay finds research applications in the following fields: genetic toxicology, monitoring of DNA repair following chemotherapy and radiotherapy, ecotoxicology, animal and human nourishment, biomonitoring of genotoxicity, epidemiology and assessment of material deposited in sperm and blood banks.

1. A study of the incidence of chromosome instability in the Japanese quail as assessed by sister chromatid exchange (SCE) and fragile site identification in chromosomes was conducted in two parent breeds and their F1 and F2 generations.2. The mean incidence of SCEs was 6.02 ± 0.45 and the frequency of fragile sites was 1.17 ± 0.79.3. There were moderately negative correlations of 0.51–0.64 between chromosome instability and fertility in the F1 and 0.10–0.23 in the F2. The hatch of fertilised eggs was negatively correlated with the number of SCE in male (0.31) and female (0.33) F1 and was lower in P (0.18 and 0.19, respectively), whereas the correlations were similar for the number of fragile sites in both generations (0.51–0.62).

Methylation is an epigenetic modification of DNA affecting gene expression without changing the structure of nucleotides. It plays a crucial role in the embryonic and post-embryonic development of living organisms. Methylation level is tissue and species-specific and changes with age. The study was aimed at identifying the methylation of the CDKN2B gene situated at locus bar in Polbar chickens on the 6th and 18th day of embryonic development using the MSP (methylation-specific PCR) method. Methylation was not detected in the promoter region of gene CDKN2B on the 6th and 18th day of embryonic development. As one of the five genes responsible for melanine activity in melanocytes and highly active, it can contribute to the production of this pigment. The present research broadens the current knowledge of the chicken epigenome and the mechanism of autosexing in birds.