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V N Tikhonov

Publications and source records attributed to V N Tikhonov.

At least 19 recordsLinked to original sources
PubMed2005

[The development of the gene pool in the microevolution of Sus scrofa and the role of heterozygosity in the breed-forming process].

The gene pool formation of the modem domestic breeds of pig Sus scrofa domestica and their genesis based on hybridization of wild ancestral forms of the European and Asian origin were studied using molecular immunogenetic methods. Males of the European and Central Asian S. scrofa subspecies (S. s. scrofa and S. s. nigripes were hybridized with domestic pigs of the Swedish Landrace and Vietnamese Black Masked breeds. In addition, we examined the genotypic structure of 65 wild, aboriginal, and local populations as well as cultured breeds, including the stock breeds with different levels of selection. Frequencies of alleles and suballelles of the chromosome 4 locus controlling antigens of the L blood group system were analyzed. The origin of marker suballeles of the European and Asian origin was estimated in the most widespread world pig breeds. Unexpectedly, a strikingly high frequency of the Asian elements was found in the most productive European and American breeds, as well as in the best breeds of Russia and other CIS countries. Only one form of heterozygosity (bcgi/bdfi) was found in a population of wild European ancestors, whereas domestic pig breeds displayed heterozygosity for far more numerous suballeles of the locus studied. Animals heterozygous for alleles of the European and Asian origin showed higher adaptivity and fertility.

Animals↗
PubMed2000

[Formation of a gene pool of miniature Siberian swine "Minisibs" and their use in medico-genetic research].

The results of 35-year breeding of a new variety of laboratory animals for biological and medical studies, termed Minisibs (miniature Siberian swine), are summarized. Minisibs were obtained via hybridization between Swedish Landrace pigs, who have an epistatic white coat color, and black Vietnamese masked pigs of breed I, who have genes of dwarfism. Some genes of wild boars Sus scrofa scrofa and S. s. nigripes from Central Europe and Central Asia, respectively, were introduced to the Minisibs gene pool in order to strengthen the constitution, increase the general resistance, and improve the functions of the cardiac muscle and valves. The pigs were selected for a decrease in body weight and an increase in litter size over 15 generations. Immunogenetic and chromosomal polymorphisms were constantly monitored by Robertsonian translocations Rb 15/17 and Rb 16/17 introduced from boars. Long-term breeding produced a population of laboratory pigs with an average adult weight of approximately 60 kg, a litter size of seven to eight piglets, and quiet behavior. Most of animals used in selection were white, which is essential for radiobiological experiments and studies on skin histocompatibility. Introduction of chromosomal polymorphism to the minipig gene pool and long-term immunogenetic and cytogenetic monitoring made it possible to perform subchromosomal mapping of the loci of some blood-group systems associated with the loci controlling coat color, litter size, stress resistance and meat quality (halothane sensitivity), and histocompatibility. Minisibs have been successfully used in numerous biomedical studies and in therapeutic and surgical cardiology (for production of diagnostic sera controlling lipid metabolism and of biological prostheses of cardiac valves). The anatomical and physiological similarity of Minisibs to humans indicate that these animals may serve as donors of xenografts for orthotopic heart transplants to humans.

Animals↗
PubMed1998

[Formation of genetic polymorphism in connection with phylogenesis and microevolution of the domestic dog Canis familiaris L].

The analysis of genetic relationships between numerous breeds and populations of domestic dogs of Asian and European origin was performed by studying their polymorphism for 14 loci of biochemical markers. Phylogenetic positions of different breed groups, related to one another and to ancestral forms from the center of domestication, were elucidated. Directions of gene flow in the formation of breed as well as dynamics and vectors of the forming genetic structure in microevolution of this extremely polytypic species, were established.

Animals↗
PubMed1998

[Population genetic parameters of aboriginal Yakut horses as related to modern breeds of the domestic horse Equus caballus L].

This study was the first to analyze the polymorphic characteristics of a wide range of biochemical markers in aboriginal Yakut horses. A total of 124 alleles, including 48 alleles of seven blood-group loci and 76 alleles of ten loci for enzymes and other proteins, were studied. For these polymorphic systems, a computer analysis of the genetic distances between 85 horse breeds of different origin from all parts of the world was performed. The low level of hereditary variation in the Yakut horses confirmed that this breed is old and has long been an isolated population. Phylogenetic analysis demonstrated that Yakut horses exhibited the most genetic similarity to the breeds from the Central Asian cluster, such as Akhal Teke, Arabian, Yabou, and Caspan Pony (Iran). The dispersal route of ancient horses was revealed. It led from America through Siberia and Central Asia to Africa and Eastern Europe, where evidence of the earliest domestication of horses was found. Genetic and ecological explanations of the formation of racing and draft breeds with similar immunogenetic characteristics are advanced. These explanations agree with craniological data on fossils and with the relative rates of growth of the axial and peripheral skeletons in modern breeds. These data shed light on the initial stages of domestication of the horse, an event that was extremely important for development of the human civilization.

Animals↗
PubMed1990

[Immunogenetic characteristics of the gene fund of Kakhetian swine and dynamics of population parameters in several generations].

Some peculiarities of gene fund and dynamics of populational characters of the oldest in Europe Kakhetian (Georgian) pigs were investigated during 18 years (10 generations). Genetic peculiarity of the aboriginal species populations in conditions of intensive pressure of natural selection and relatively weak artificial selection was determined with the help of codominant alleles of the blood groups E system. Considerable qualitative and quantitative differences were detected between Kakhetian pigs and all subspecies of European boars and domestic pigs of cultured breeds studied. Kakhetian pigs are strongly similar to wild boar, as concerns their morpho-physiological and behavioral characteristics. However, the assumption that they originated from Romanian (Caucasian) wild boar by direct domestication, without hybridization, is wrong, since they have alleles which are never found in European wild boars. The results of comparative study of Kakhetian and other domesticated and wild pig forms characteristics makes it possible to suppose that the presence in Kakhetian pigs gene fund of some alleles of East Asian origin is due to a certain participation of the Large White and Mangalica breeds in their phylogenesis. The two latter breeds, in their turn, obtained these alleles as a result of two waves of pig importation in Europe from the South-East Asia (on the eve of a.d. and about 150-200 years ago). This is indirectly confirmed by historical and zootechnical data.

Alleles↗
PubMed1988

[Genetic relationship of the loci of phosphohexose isomerase and G-system blood groups in swine].

The hybridological analysis for gene mapping of the locus of phosphohexose isomerase (PHI) of pigs was carried out. The locus of G blood group system was used as a marker of the chromosome 15. 26 families with 200 piglets were obtained from backcross matings. The analysis of haplotype segregation pointed to the lack of independent inheritance of PHI and G systems loci and to weak linkage between these loci. The recombination frequency was estimated to be 39%. The results obtained are discussed in connection with the problem of establishment of accurate gene maps.

Animals↗
PubMed1981

[Genetic characteristics of the 1st Soviet miniswine, Minisibs (miniature Siberian swine). I. The breeding of Minisibs and their morphophysiological properties].

The first form of laboratory mini-pigs "Minisibs" (miniature siberian swine) in USSR is the result of the distant hybridization and of the system of complex crosses between domestic and wild pigs of European and Asiatic origin (Sweden Landrace, Black Vietnamese, Sus scrofa ferus, Sus scrofa nigripes). "Minisibs" have a very small size, their live weight at birth is 517.16 +/- 6.48 g, at the age of two months--4.72 +/- 0.13 kg, at the age of 6 months when sexual maturity is achieved--19.02 +/- 0.89 kg and at the age of 12 months when they are adult males--29.75 +/- 2.98, females--35.35 +/- 0.01 kg. More than 88% of "Minisibs" are white, they have calm behaviour, are omnivorous, tolerant to a wide range of ecological conditions. "Minisibs" have a set of immunogenetical and cytogenetical features, in which they differ from other known miniature pigs. One of these features is the chromosome polymorphism: "Minisibs" have a 2n = 38, 37 and 36 karyotypes. "Minisibs" are very similar to a man in morphological and physiological parameters of many organs, and in the course of various pathological processes. For these reasons, mini-pigs "Minisibs" can be efficiently used as the best adequate model in the large scope of medical and biological programmes.

Animals↗