New possibilities of effective breeding in cattle based on the study of the genome

Abstract

The article contains generalized literary data on the results of genome research based on molecular genetic methods in connection with the productive qualities of cattle that can be used to accelerate and improve breeding work. The study of the human genome has given impetus to the development of medicine, biotechnology and pharmacogenetics. Similarly, new research on the genome of cattle gives qualitatively different possibilities for using these data in the selection and production of agricultural products, as well as in controlling its quality. Molecular genetic markers inform about the polymorphism of genes and allow to detect individual genes and gene complexes that carry information about a certain feature. Based on such studies, gene pool can be formed with a certain combination. An alternative way of molecular-genetic marking of performance is to study the polymorphism of structural genes, allelic variants which are directly related to the desired phenotypic manifestation, namely: kappa-casein (CSN3), veta-lactaglobulin (BLG), somatotropin (GH), and myostatin (MSTN). Modern breeding work with cattle is associated with the establishment of a connection between the polygenic signs of productivity and the «main» genes of quantitative traits, the polymorphism of which affects the final output of the protein product. As candidate genes that affect lactation productivity in cattle, first of all the genes of milk proteins, in particular kappa-casein, are examined. The gene for the somatotropic hormone (GH), a growth hormone in cattle, is a polypeptide consisting of 191 amino acids and is encoded by a single gene, which is localized in 19 chromosomes. Growth hormone plays a key role in stimulating the synthesis of protein, cell division, and body growth. Myostatin – one of the regulators of skeletal muscle development is the myostatin gene, which refers to a family of transforming growth factors. The gene of myostatin in the Bovine species is localized in chromosome 2 and carries the muscle hypertrophy locus, there is also a homologous fragment of human chromosome 2, where the locus of this gene is limited. The presence of the gene of myostatin, as one of the locus of quantitative traits of beef, can be used as a marker for genetic mapping. After discovering mutations in the gene of the myostatin, they came to the conclusion, that it is not the only gene that controls the growth and muscle mass of animals. Molecular genetic markers allow you to receive information about the polymorphism of genes and to identify individual genes and gene «ensembles» that carry the desired complex of features.