Molecular-genetic bases of plumage coloring in chicken

The color of plumage in birds is an important feature, often determining descent to a particular species or breed. It serves as a key factor in the interaction of birds with each other due to their well-developed visual perception of the surrounding world. In poultry including chickens, the color of the plumage can be treated as a genetic marker, useful for identifying breeds, populations and breeding groups with their specific traits. The origin of diverse color plumage is the result of two interrelated physical processes, chemical and optical, due to which pigment and structural colors in the color are formed. The pigment melanin, which is presented in two forms, eumelanin and pheomelanin, is widely spread in birds. The basis for the formation of melanin is the aromatic amino acid tyrosine. The process of melano-genesis involves many loci, part of the complex expression of plumage color genes. In birds, the solid black color locus encodes the melanocortin 1 receptor (MC1R), mutations in which lead to a change in receptor activation and form different variants of the E locus. Using the GWAS analysis, possible genes affecting the formation of color in chickens were detected. The biosynthesis and types of melanin are affected by the activity of the enzyme tyrosine, and mutations in the tyrosinase gene (TYR) cause albinism in different species. The formation mechanism of brown, silver, gold, lavender and a number of other shades is determined by the influence on the work of the MC1R genes and TYR specific modifier genes. Thus, locus I currently associated with the PMEL17 gene inhibits the expression of eumelanin, and the MLPH gene affects tyrosinase function. Research on the mechanisms of formation of the secondary coloring of plumage in chickens is being actively conducted nowadays. The formation of a marble feather pattern is associated with the mutation of the endothelin B2 receptor (EDNRB2), in the coding part of the gene of which a polymorphism is found associated with the mo locus. The molecular base that causes the feather banding (locus B and autosomal recessive banding) is identified. Today, only some genes that determine the color of the plumage of chickens are studied and described. Different genes can produce similar plumage patterns, and different phenotypes can be determined by the polymorphism of a single gene. Using molecular methods, you can more accurately identify these differences. This overview shows the nature of melanin coloration in birds using the example of chickens of various breeds and also attempts to systematize knowledge about the molecular-genetic mechanisms of the appearance of various types of coloration

Efficiency of using SNP markers in the <i>MSTN</i> gene in the selection of the Pushkin breed chickens

In the poultry industry, indicators reflecting the growth rate of young stock and the exterior characteristics of chickens are important benchmarks for breeding. Traditional selection based on phenotypic evaluation is characterized by low efficiency with a low character inheritance ratio and is difficult to apply in small groups of animals and birds bred in bioresource collections. The use of molecular genetic markers associated with economically important traits makes it possible to carry out early selection of birds. This entails an increase in the profitability of the poultry industry. Recently, single nucleotide polymorphisms (SNPs) have served as convenient markers for selection purposes. For five generations (P1–P5), an experimental selection of hens of the Pushkin breed was carried out for live weight. It was based on selection for single nucleotide polymorphism rs313744840 in the MSTN gene. As a result, a significant increase in the frequency of allele A in this gene, from 0.11 to 0.50, took place. The association of SNP markers with meat qualities in the experimental group led to changes in the exterior profile of an adult bird at 330 days of age. The individuals with the AA and AG genotypes had the greatest live weight and longest body. As a result of selection, the bird on average became larger due to an increase in the number of heterozygous individuals with long bodies and large chest girths. The depth of the chest and the width of the pelvis increased due to an increase in the frequency of allele A in the experimental population. A tendency towards an increase in these indicators with the substitution of G with A in the genotype was found. Saturation of the population with desirable alleles led to an increase in the average live weight of the chickens. Analysis of the exterior parameters of adult birds showed that this growth is achieved by increasing the depth and volume of the bird body, and not by increasing the length of the limbs. Thus, marker selection carried out for five generations in the experimental population of Pushkin breed chickens to increase body weight has reliably (p &lt; 0.001) changed the exterior profile of adult birds

Research in the history of the profession as an essential part oh the formation of a specialist

In this research we have shown the necessity of studying history of Pharmacy as a factor of completely developed specialist in Pharmacy on the example of the history of forming specialist “pharmacist” using general scientific theoretical method (analysis). In this study we have monitored the influence of historical knowledge of this aspect on the modern scientific medical society.В настоящем исследовании при помощи теоретического общенаучного метода (анализа), выявляется необходимость изучения истории профессии как фактора полноценного формирования специалиста на примере специальности «фармацевт». В ходе работы на данном уровне исследования удалось проследить процесс влияния исторических знаний в данном аспекте на формирование будущего специалиста

Динамика роста показателей экстерьера и интерьера в онтогенезе у кур генофондных популяций и бройлеров

Conformities of intensity of growth of muscles and bones of the skeleton in relation to the growth of body weight in chickens of the combined type of productivity and broilers have been studied. The research subject were chickens of meat and egg populations: experimental golden-striped (GS), Pushkinskaya from the bioresource collection of Russian Research Institute of Farm Animal Genetics and Breeding and broilers of the Ross 308 cross. The absolute values of body weight, muscle mass, length and thickness of skeletal bones in different age periods were calculated. Studies have shown that the mass of the pectoral and leg muscles has the highest growth rate in all the studied groups. The growth rate of the exterior and interior indicators decreases unevenly with age, especially in broiler chickens. The intensity of the growth of muscles and bones of the skeleton relative to the growth of body weight has been studied using an allometric equation. Studies have shown that the growth of the pectoral and leg muscles in all groups of chickens in the period up to 10 weeks of life outstrips the growth of the body as a whole. The growth of skeletal bones is characterized by negative allometry. Knowledge of the patterns of growth and development of the bird organism and its individual parts allows to adjust the feeding diet depending on the growth period, monitor the correctness of development and deviations from the standard, as well as choose the most informative periods for the selection of breeding birds. Изучены закономерности интенсивности роста мышц и костей скелета по отношению к росту живой массы у цыплят комбинированного типа продуктивности и бройлеров. Объектом исследования послужили цыплята мясо-яичных популяций: опытная золотисто-полосатая (ЗП), пушкинская из биоресурсной коллекции ВНИИГРЖ и бройлеры кросса Росс 308. Рассчитаны абсолютные значения живой массы, массы мышц, длины и толщины костей скелета в разные возрастные периоды. Исследования показали, что наиболее высокой скоростью роста обладает масса грудных и ножных мышц во всех исследуемых группах. Скорость роста показателей экстерьера и интерьера с возрастом снижается неравномерно, особенно у цыплят-бройлеров. Изучена интенсивность роста мышц и костей скелета относительно роста живой массы с помощью аллометрического уравнения. Установлено, что рост грудных и ножных мышц у всех групп цыплят в период до 10 недель жизни опережает рост организма в целом. Рост костей скелета характеризуется отрицательной аллометрией. Знание закономерностей роста и развития организма птиц и отдельных его частей позволяют корректировать рацион кормления в зависимости от периода роста, отслеживать правильность развития и отклонения от нормы, а также выбирать наиболее информативные периоды для отбора племенной птицы

Plants of the genus Echinacea: chemical composition, pharmacological actions and preparations based on them

The analysis of the world literature on the study of species of the genus Echinacea. Echinacea angustifolia DC., Echinacea purpurea Moench., Echinacea pallida Nutt. contain a rich chemical composition, which is dominated by alkylamides, sugars, polysaccharides, coffee acid derivatives, saponins, fatty oils, essential oils. Immunomodulatory effect is confirmed by long-term experience of traditional medicine and modern scientific data.Проведен анализ мировой литературы изученности видов рода Echinacea. Echinacea angustifolia DC., Echinacea purpurea Moench., Echinacea pallida Nutt. содержат богатый химический состав, в котором преобладают алкиламиды, сахара, полисахариды, производные кофейной кислоты, сапонины, жирные масла, эфирные масла. Иммуномодулирующее действие подтверждено многолетним опытом народной медицины и современными научными данными

Whole genome screening procures a holistic hold of the Russian chicken gene pool heritage and demographic history

Simple Summary: A collection of native farm animal breeds can be considered as a gene pool and a national heritage. Long-term artificial selection in domesticated animals has certain effects on their genomes, which can be investigated using genome-wide screens for DNA sequence variation, that is, so-called single nucleotide polymorphism (SNP) screens. Here, we looked at the genomes of 19 Russian chicken gene pool breeds, both native and imported, evaluating the contrasting egg, meat and dual-purpose types. Based on genetic diversity statistics, we identified differences between the breeds using many DNA markers (SNPs) that may represent genomic regions that are being selected for, either within a specific breed or shared between breeds. Our research will be helpful for further understanding the genomic diversity and demographic history of Russian domestic chickens. This would be essential for their successful breeding. Abstract: A study for genomic variation that may reflect putative selective signaling and be associated with economically important traits is instrumental for obtaining information about demographic and selection history in domestic animal species and populations. A rich variety of the Russian chicken gene pool breeds warrants a further detailed study. Specifically, their genomic features can derive implications from their genome architecture and selective footprints for their subsequent breeding and practical efficient exploitation. In the present work, whole genome genotyping of 19 chicken breeds (20 populations with up to 71 samples each) was performed using the Chicken 50 K BeadChip DNA chip. The studied breed sample included six native Russian breeds of chickens developed in the 17th–19th centuries, as well as eight Russian chicken breeds, including the Russian White (RW), created in the 20th century on the basis of improving local chickens using breeds of foreign selection. Five specialized foreign breeds of chickens, including the White Leghorn (WL), were used along with other breeds representing the Russian gene pool. The characteristics of the genetic diversity and phylogenetic relationships of the native breeds of chickens were represented in comparison with foreign breeds. It was established that the studied native breeds demonstrate their own genetic structure that distinguishes them from foreign breeds, and from each other. For example, we previously made an assumption on what could cause the differences between two RW populations, RW1 and RW2. From the data obtained here, it was verified that WL was additionally crossed to RW2, unlike RW1. Thus, inherently, RW1 is a purer population of this improved Russian breed. A significant contribution of the gene pool of native breeds to the global genetic diversity of chickens was shown. In general, based on the results of a multilateral survey of this sample of breeds, it can be concluded that phylogenetic relationships based on their genetic structure and variability robustly reflect the known, previously postulated and newly discovered patterns of evolution of native chickens. The results herein presented will aid selection and breeding work using this gene pool

Disentangling clustering configuration intricacies for divergently selected chicken breeds

Divergently selected chicken breeds are of great interest not only from an economic point of view, but also in terms of sustaining diversity of the global poultry gene pool. In this regard, it is essential to evaluate the classification (clustering) of varied chicken breeds using methods and models based on phenotypic and genotypic breed differences. It is also important to implement new mathematical indicators and approaches. Accordingly, we set the objectives to test and improve clustering algorithms and models to discriminate between various chicken breeds. A representative portion of the global chicken gene pool including 39 different breeds was examined in terms of an integral performance index, i.e., specific egg mass yield relative to body weight of females. The generated dataset was evaluated within the traditional, phenotypic and genotypic classification/clustering models using the k-means method, inflection points clustering, and admixture analysis. The latter embraced SNP genotype datasets including a specific one focused on the performance-associated NCAPG-LCORL locus. The k-means and inflection points analyses showed certain discrepancies between the tested models/submodels and flaws in the produced cluster configurations. On the other hand, 11 core breeds were identified that were shared between the examined models and demonstrated more adequate clustering and admixture patterns. These findings will lay the foundation for future research to improve methods for clustering as well as genome- and phenomewide association/mediation analyses

Evolutionary subdivision of domestic chickens: implications for local breeds as assessed by phenotype and genotype in comparison to commercial and fancy breeds

To adjust breeding programs for local, commercial, and fancy breeds, and to implement molecular (marker-assisted) breeding, a proper comprehension of phenotypic and genotypic variation is a sine qua non for breeding progress in animal production. Here, we investigated an evolutionary subdivision of domestic chickens based on their phenotypic and genotypic variability using a wide sample of 49 different breeds/populations. These represent a significant proportion of the global chicken gene pool and all major purposes of breed use (according to their traditional classification model), with many of them being characterized by a synthetic genetic structure and notable admixture. We assessed their phenotypic variability in terms of body weight, body measurements, and egg production. From this, we proposed a phenotypic clustering model (PCM) including six evolutionary lineages of breed formation: egg-type, meat-type, dual purpose (egg-meat and meat-egg), game, fancy, and Bantam. Estimation of genotypic variability was carried out using the analysis of five SNPs, i.e., at the level of genomic variation at the NCAPG-LCORL locus. Based on these data, two generally similar genotypic clustering models (GCM1 and GCM2) were inferred that also had several overlaps with PCM. Further research for SNPs associated with economically important traits can be instrumental in marker-assisted breeding programs

Selection-driven chicken phenome and phenomenon of pectoral angle variation across different chicken phenotypes

An appreciation of the synergy between genome and phenome of poultry breed is essential for a complete understanding of their biology. Phenotypic traits are shaped under the influence of artificial, production-oriented, selection that often acts contrary to that which would occur during natural selection. In this comparative study, we analysed the phenotypic diversity of 39 chicken breeds and populations that make up a significant part of the world gene pool. Grouping patterns of breeds found within the traditional, phenotypic models of their classification/clustering required in-depth analysis using sophisticated mathematical approaches. As a result of studying performance and conformation phenotypes, a phenomenon of previously underestimated variability in pectoral angle (PA) was revealed. Moreover, patterns of PA relationship with productive traits were analysed. We propose using PA measurement as a promising new auxiliary index for selecting hens and roosters of breeding flocks in egg production improvement programs

Comparative analysis of molecular RFLP and SNP markers in assessing and understanding the genetic diversity of various chicken breeds

Monitoring the genetic diversity of small populations is important with respect to conserving rare and valuable chicken breeds, as well as discovery and innovation in germplasm research and application. Restriction fragment length polymorphisms (RFLPs), the molecular markers that underlie multilocus DNA fingerprinting (MLDF), have historically been employed for this purpose, but over the past two decades, there has been an irreversible shift toward high-throughput single-nucleotide polymorphisms (SNPs). In this study, we conducted a comparative analysis of archived MLDF results and new data from whole-genome SNP genotyping (SNPg) among 18 divergently selected breeds representing a large sample of the world gene pool. As a result, we obtained data that fit the general concept of the phylogenetic distribution of the studied breeds and compared them with RFLP and SNP markers. RFLPs were found to be useful markers for retrospective assessment of changes in the genetic architecture and variability underlying the phenotypic variation in chicken populations, especially when samples from previous generations used for MLDF are unavailable for SNPg. These results can facilitate further research necessary to assess the possibility of extrapolating previous MLDF results to study the long-term dynamics of genetic diversity in various small chicken germplasm populations over time. In general, the whole-genome characterization of populations and breeds by multiple SNP loci will further form the basis for the development and implementation of genomic selection with the aim of effective use of the genetic potential of the domestic gene pool in the poultry industry