Genetic polymorphism of erythrocytic enzymes in Yakut populations

Polymorphism of the erythrocytic enzymes PGM1, ACP1, ESD, and GLO1 was found in Yakut populations. The allelic frequencies of the polymorphic systems studied varied within the following ranges: PGM1*1+, 0.5833-0.7791; PGM1*1-, 0.0345-0.1176; PGM1*2+, 0.1250-0.2813; ACP1*A, 0.1429-0.3382; ACP1*B, 0.6548-0.8571; ESD*2, 0.1250-0.4643; and GLO1*1, 0.0116-0.2845.     

Genetic Polymorphism of Erythrocytic Enzymes in Yakut Populations

Polymorphism of the erythrocytic enzymes PGM1, ACP1, ESD, and GLO1 was found in Yakut populations. The allelic frequencies of the polymorphic systems studied varied within the following ranges: PGM1*1+, 0.5833–0.7791; PGM1*1–, 0.0345–0.1176; PGM1*2+, 0.1250–0.2813; ACP1*A, 0.1429–0.3382; ACP1*B, 0.6548–0.8571; ESD*2, 0.1250–0.4643; and GLO1*1, 0.0116–0.2845.     

Genetic and Demographic Structure of the Yakut Population: Reproduction Indices

Genetic and demographic information for the Yakut population living in the Republic of Sakha (Yakutia) is presented. The mean number of children per woman constituted 4.605. Crow's index (I _tot) and its components (I _m and I _f) were 0.483, 0.104, and 0.343, respectively.     

Genetic Peculiarity of the Yakut Population as Inferred from Autosomal Loci

The autosomal gene pool of Yakuts was analyzed with a panel of polymorphic Alu insertions. The observed allele frequencies were typical for other Asian ethnic groups. Genetic differentiation of three Yakut populations was relatively high, 2%. East Siberian ethnic groups were shown to have a common gene pool and to experience no intense gene flow from other populations. Development of the Yakut gene pool was assumed to involve no substantial genetic effect of neighboring populations. The results fit both autochthonous and southern origin hypotheses.     

Genetic markers of an aboriginal Taiwanese population

A group of Taiwan aborigines, the Toroko, was typed for 21 classical genetic loci. This is part of an ongoing program aimed at a comprehensive study of Taiwan aborigines. In this first paper a short summary of historical, archeological, and anthropological data in the literature is made, and results of the present survey are compared with older results from other aborigine tribes. An analysis of other neighboring populations from southeast Asia has also been carried out in order to give a preliminary answer to the question of origin of Taiwanese aborigines. Fifteen populations were studied for 13 loci by tree analysis, principal components, and isolation by distance. Tree analysis and principal component analysis gave results in fairly good agreement and indicate three major population clusters: a northeast cluster (Ainu, Korea, Japan, and Ryukyu); a southeast cluster (south China, Thailand, Vietnam, Philippines, Taiwan, and Toroko); and a third cluster including Malaya and Borneo. The positions of Polynesia, Micronesia, and Melanesia are somewhat peripheral. Analysis of the tree shows some potential cases of convergence, perhaps owing to admixture, and of divergence. The analysis of isolation by distance shows that geographic propinquity is a reasonably good predictor of general similarity in this area.     

Differentiation of four Indian aboriginal cattle populations revealed by STR markers

Cattle are the most important livestock in India and play a pivotal role in agrarian economy. There are 34 recognized breeds of cattle and number of unexplored lesser known populations. The present study is a contribution towards determining genetic variation and understanding the relationship among four lesser known populations. A total of 194 unrelated DNA samples from three cattle populations of Orissa (Binjharpuri, Ghumsuri, Motu) and Hill cattle of Kumaun (Kumauni) were collected from respective breeding tracts. Genotyping was done with 23 bovine microsatellite markers as suggested by International Society for Animal Genetics (ISAG) and FAO (DAD-IS) on automated sequencer. The average observed heterozygosity in the four populations lie within the narrow range of 0.623 +/- 0.04 in Binjharpuri to 0.664 +/- 0.03 in Kumauni. Mean estimates of observed and expected heterozygosity over all loci and breeds were 0.651 +/- 0.02 and 0.720 +/- 0.01, respectively. In the overall population, the homozygote excess (F(IT)) of 0.132 +/- 0.03, was partly due to the genetic differentiation among breeds (F(ST) = 0.044 +/- 0.01) and, to a larger extent, to a significant homozygote excess within breeds (F(IS) = 0.094 +/- 0.03). The phylogenetic reconstruction from a UPGMA clustering based on Nei's Standard genetic distance yielded a tree with Binjharpuri and Ghumsuri on a single node and Motu and Kumauni on separate nodes. The most probable clustering detected by STRUCTURE in population was three. Binjharpuri and Ghumsuri animals were assigned to one cluster with high proportion of membership.     

Differentiation of four indian aboriginal cattle populations revealed by SIR markers

Cattle are the most important livestock in India and play a pivotal role in agrarian economy. There are 34 recognized breeds of cattle and number of unexplored lesser known populations. The present study is a contribution towards determining genetic Variation and understanding the relationship among four lesser known populations. A total of 194 unrelated DNA samples from three cattle populations of Orissa (Binjharpuri, Ghumsuri, Motu) and Hill cattle of Kumaun (Kumauni) were collected from respective breeding tracts. Genotyping was done with 23 bovine microsatellite markers as suggested by International Society for Animal Genetics (ISAG) and FAO (DAD-IS) on automated sequencer. The average observed heterozygosity in the four populations lie within the narrow range of 0.623 ± 0.04 in Binjharpuri to 0.664 ± 0.03 in Kumauni. Mean estimates of observed and expected heterozygosity over all loci and breeds were 0.651 ± 0.02 and 0.720 ± 0.01, respectively. In the overall population, the homozygote excess (F _IT) of 0.132 ± 0.03, was partly due to the genetic differentiation among breeds (F _ST = 0.044 ± 0.01) and, to a larger extent, to a significant homozygote excess within breeds (F _IS = 0.094 ± 0.03). The phylogenetic reconstruction from a UPGMA clustering based on Nei??s Standard genetic distance yielded a tree with Binjharpuri and Ghumsuri on a single node and Motu and Kumauni on separate nodes. The most probable clustering detected by STRUCTURE in population was three. Binjharpuri and Ghumsuri animals were assigned to one cluster with high proportion of membership.     

Genetic relationship between the neurological (excitability thresholds) and the behavioral characteristics of mouse strains and their hybrids

The comparative genetic analysis of 16 inbred mouse strains was carried out for excitability thresholds of peripherical parts of the nervous system, viability to learning, short-term memory and exploratory activity in different experimental conditions. The high positive correlation was shown between excitability thresholds of different parts of the peripherical nervous system, the high negative correlation being established between excitability thresholds, viability to learning, short-term memory and exploratory activity. The data led to the conclusion about the existence of the pleiotropic effect of genes controlling the excitability thresholds, on peculiarities of behaviour. This was confirmed by the findings obtained in the study of various hybrids, which point to the similar way of inheritance of excitability thresholds and behavioural patterns.     

Genetic characteristics of erythrocyte antigens and various polymorphic blood proteins in the Jersey cattle in Moldavia

The results of the study of immunogenetic structure characteristics of both the purebred Jersey and different generations of the Red-stepp x Jersey, Jersey x Golshtin, Jersey x Golshtin x Red-stepp are presented. We used 47 to 61 reagents and studied 8 types of blood proteins. Some differences in allele frequencies of a number of loci were revealed between the groups studied. This fact shows the possibility of their using as markers in breed crossing.     

Genetic regulation of CFA expression in interspecific avian hybrids and somatic cell hybrids

Chicken fetal-leukemic antigen (CFA) is an oncodevelopmental antigen present on embryonic and neonatal chicken peripheral red blood cells (RBCs) but is not restricted to fetal stages of development in other avian species. Crosses between white Leghorn chickens and Japanese quail resulted in adult hybrids whose peripheral RBCs were positive for CFA. Of the four CFA determinants normally found in adult quail RBCs, only two were present on quail-chicken hybrid RBCs. Adult quail--chicken hybrid RBCs also possessed on CFA determinant associated with early development in both quail and chicken and one chicken-specific CFA determinant. Evidence is presented for the possible association of CFA-positive adult peripheral RBCs and the level of circulating reticulocytes. Crosses between pheasant and turkey (both with CFA-positive adult RBCs) resulted in hybrid adult RBCs expressing only a portion of the parental CFA determinants. Through the formation of somatic cell hybrids between adult chicken and embryonic Japanese quail RBCs, it was possible to induce the appearance of CFA determinants normally restricted to embryonic chicken RBCs. Approximately 50% of the hybrid cells showed reexpression of CFA, and this induction was both time and temperature dependent. Hybridization between RBCs of adult chicken and those of either adult Japanese quail or adult turkey failed to elicit the reexpression of chicken-specific CFA.     

MtDNA and Y-chromosome lineages in the Yakut population

The structure of female (mtDNA) and male (Y-chromosome haplotypes) lineages in the Yakut population was examined. To determine mtDNA haplotypes, sequencing of hypervariable segment I and typing of haplotype-specific point substitutions in the other parts of the mtDNA molecule were performed. Y haplogroups were identified through typing of biallelic polymorphisms in the nonrecombining part of the chromosome. Haplotypes within haplogroups were analyzed with seven microsatellite loci. Mitochondrial gene pool of Yakuts is mainly represented by the lineages of eastern Eurasian origin (haplogroups A, B, C, D, G, and F). In Yakuts haplogroups C and D showing the total frequency of almost 80% and consisting of 12 and 10 different haplopypes, respectively, were the most frequent and diverse. The total part of the lineages of western Eurasian origin ("Caucasoid") was about 6% (4 haplotypes, haplogroups H, J, and U). Most of Y chromosomes in the Yakut population (87%) belonged to haplogroup N3 (HG16), delineated by the T-C substitution at the Tat locus. Chromosomes of haplogroup N3 displayed the presence of 19 microsatellite haplotypes, the most frequent of which encompassed 54% chromosomes of this haplogroup. Median network of haplogroup N3 in Yakuts demonstrated distinct "starlike phylogeny". Male lineages of Yakuts were shown to be closest to those of Eastern Evenks.     

Genetic composition of Chilean aboriginal populations: HLA and other genetic marker variation

Phenotypes and gene frequencies for eight genetic systems are presented for five Chilean Indian tribes. Results agree with the pattern expected for Andean Indians. Genetic distances and dendrograms were obtained separately for HLA and traditional genetic markers. The similarity of both is noteworthy. Linguistic distances exhibit a correlation with genetic distances based on traditional markers. © 1996 Wiley-Liss, Inc.     

牛RXRG基因遗传变异与双胎性状的关联分析

以视黄素X受体基因g(retinoid X receptor-gamma, RXRG)作为牛双胎性状的候选基因, 运用测序法寻找牛RXRG基因SNPs, 筛查到一个新的多态位点A1941G, 该位点位于3′UTR。运用PCR-RFLP法验证并分析该位点在鲁西牛双胎群体和单胎群体及中国西门塔尔牛、安格斯牛和西蒙杂交牛单胎群体间的多态性, 结果表明, 在鲁西牛双胎和单胎群体中分布A、B两个等位基因,处于中度多态。经χ2适合性检验, 鲁西双胎牛群体在该位点未达到Hardy-Weinberg平衡状态(P < 0.05)。将鲁西牛群体的A1941G位点的基因型效应与双胎性状进行关联分析, 卡方独立性检测结果显示, 基因型分布在鲁西单、双胎牛群体上差异达到极显著水平(P < 0.01)。     

MtDNA and Y-Chromosome Lineages in the Yakut Population

The structure of female (mtDNA) and male (Y-chromosome haplotypes) lineages in the Yakut population was examined. To determine mtDNA haplotypes, sequencing of hypervariable segment I and typing of haplotype-specific point substitutions in the other parts of the mtDNA molecule were performed. Y haplogroups were identified through typing of biallelic polymorphisms in the nonrecombining part of the chromosome. Haplotypes within haplogroups were analyzed with seven microsatellite loci. Mitochondrial gene pool of Yakuts is mainly represented by the lineages of eastern Eurasian origin (haplogroups A, B, C, D, G, and F). In Yakuts haplogroups C and D showing the total frequency of almost 80% and consisting of 12 and 10 different haplopypes, respectively, were the most frequent and diverse. The total part of the lineages of western Eurasian origin (Caucasoid) was about 6% (4 haplotypes, haplogroups H, J, and U). Most of Y chromosomes in the Yakut population (87%) belonged to haplogroup N3 (HG16), delineated by the T–C substitution at the Tat locus. Chromosomes of haplogroup N3 displayed the presence of 19 microsatellite haplotypes, the most frequent of which encompassed 54% chromosomes of this haplogroup. Median network of haplogroup N3 in Yakuts demonstrated distinct starlike phylogeny. Male lineages of Yakuts were shown to be closest to those of Eastern Evenks.     

Genetic variation within the Hereford breed of cattle

Genetic differentiation among Hereford populations from Britain, Ireland, Sweden, Canada and New Zealand together with six other beef breeds was assessed using blood type polymorphisms. Changes in the genetic structure of the British Hereford population over time were also examined. Loci surveyed were seven red cell antigen systems (A, B, C, F, L, S, Z), and two serum protein loci (transferrin and albumin). Within group variation was measured by the average expected heterozygosity, and between group relationships by genetic distance. There was significant genetic differentiation among Hereford populations from different countries. Differences between Hereford groups, however, were not as large as differences between breeds. There were also significance differences among British herds. The proportion of Canadian genes in the British 'hybrid' population was estimated to have increased from 0·42 (±0·34) in the 1970s to 0·98 (±0·11) in the 1990s. Canadian Hereford groups were found to be less heterozygous than other groups, and replacement of the British population with Canadian animals may lead to loss of variation. Breeding strategies that preserve original native genes in British Hereford populations should be considered by commercial breeders, in order to prevent the long-term loss of genetic variation within the breed.     

Genetic aspects of twinning in cattle

Twinning in cattle ranges from about 1% for beef breeds to about 4% for dairy breeds. The incidence of double births may have both positive and negative effects, which mainly depends on the purpose for which the cattle are raised. Because of freemartinism, as well as management problems connected e.g. with a greater risk of dystocia and retained placenta, it is an undesirable trait in dairy herds. In beef cattle, however, twinning can considerably increase the efficiency of production. Low heritability, a long generation interval for progeny testing, sex-limited expression and an unfavourable correlation with milk yield make twinning difficult to control by selection. Hence, it is the type of trait for which the identification of the genetic marker - quantitative trait loci (QTL) linkage and the implementation of marker-assisted selection in breeding strategies are expected to be especially beneficial. Searching for QTL influencing the reproductive rate in cattle was performed mainly in the US Meat Animal Research Center twinning herd and in the commercial Norwegian cattle population. Among several genome regions that appear to control twinning and ovulation rates, the most interesting seem to be chromosomes 5, 7, 19 and 23.