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At least 649 records · Page 36Linked to original sources
PubMed2002

Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample.

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of São Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.

Alleles↗
PubMed1999

Effects of a traditional lifestyle on the cardiovascular risk profile: the Amondava population of the Brazilian Amazon. Comparison with matched African, Italian and Polish populations.

OBJECTIVE: To determine the relationships between lifestyle and cardiovascular risk factors among the Brazilian Amondava, one of the world's most isolated populations. DESIGN: Cross-sectional, population-based study. Four age- and sex-matched samples from Brazil Africa, Italy and Poland, representing different levels of modernization, were compared. Body weight, height, blood pressure, serum cholesterol and glycaemia were measured, and a standard questionnaire administered. Data concerning dietary habits and physical activity were collected. A personal socio-economic score was calculated, on the basis of type of economy, level of formal education, type of occupation, type of habitat, availability of piped water and electricity, main source of income, housing conditions, availability of radio, television or personal computer, knowledge of a second language, and organized health facilities. SETTING: Primary epidemiological screening, at an institution. RESULTS: Among the Amondava blood pressure was always <140/90 mm Hg, it did not increase with age and was not correlated with any other variable; 46.6% of subjects had systolic blood pressure <100 mm Hg. Blood pressure among the Amondava (109.6+/-11.1/69.5+/-6.4 mm Hg) was on average lower (P<0.0001) than in all other samples. Among the Amondava, the concentration of total cholesterol was always <200 mg/dl, i.e. similar to that of Africans whose diet included large amounts of vegetable foodstuffs; 90% had glycaemia (<80 mg/dl), and their mean value was the lowest (55.1+/-14.9 mg/dl) of all the groups. CONCLUSIONS: In addition to a possible genetic predisposition not analysed in this study, a traditional lifestyle (no contact with civilization, diet based on complex carbohydrates and vegetables, high energy expenditure) may protect against the development of hypertension, hypercholesterolaemia, and diabetes.

Adolescent↗
PubMed1996

Populations genetic analysis of nuclear and mitochondrial loci in skin biopsies collected from central and northeastern North Atlantic humpback whales (Megaptera novaeangliae): population identity and migratory destinations.

It has been speculated that humpback whales, Megaptera novaeangliae, from the northeastern North Atlantic breed in tropical waters off the coast of West Africa and therefore that they represent a separate breeding population from that which winters in the West Indies. We determined the genotype at six microsatellite loci as well as the sequence of the first 288 nucleotides in the mitochondrial control region of 133 skin biopsies collected from humpback whales in the central North Atlantic (Iceland and Jan Mayen) and the northeastern North Atlantic (Bear Island and the northern coast of Norway). We detected no significant deviations from Hardy-Weinberg proportions nor any differences in genotype frequencies between localities at the nuclear loci. However, the mitochondrial analyses revealed two distinct matrilineal aggregations: the central and the northeastern North Atlantic. Our findings were not compatible with the idea of a separate eastern North Atlantic breeding ground unless one has been established recently. The proposed alternative hypothesis of a common North Atlantic panmictic population (wintering primarily in the West Indies) in which individual whales display maternally directed site-fidelity to specific feeding grounds was supported by re-sightings of two northeastern North Atlantic humpback whales in the West Indies.

Animals↗
PubMed2002

Within-host population dynamics and the evolution of microparasites in a heterogeneous host population.

Why do parasites harm their hosts? The general understanding is that if the transmission rate and virulence of a parasite are linked, then the parasite must harm its host to maximize its transmission. The exact nature of such trade-offs remains largely unclear, but for vertebrate hosts it probably involves interactions between a microparasite and the host immune system. Previous results have suggested that in a homogeneous host population in the absence of super- or coinfection, within-host dynamics lead to selection of the parasite with an intermediate growth rate that is just being controlled by the immune system before it kills the host (Antia et al. 1994). In this paper, we examine how this result changes when heterogeneity is introduced to the host population. We incorporate the simplest form of heterogeneity--random heterogeneity in the parameters describing the size of the initial parasite inoculum, the immune response of the host, and the lethal density at which the parasite kills the host. We find that the general conclusion of the previous model holds: parasites evolve some intermediate growth rate. However, in contrast with the generally accepted view, we find that virulence (measured by the case mortality or the rate of parasite-induced host mortality) increases with heterogeneity. Finally, we link the within-host and between-host dynamics of parasites. We show how the parameters for epidemiological spread of the disease can be estimated from the within-host dynamics, and in doing so examine the way in which trade-offs between these epidemiological parameters arise as a consequence of the interaction of the parasite and the immune response of the host.

Animals↗
PubMed2003

HLA genes in the Chuvashian population from European Russia: admixture of Central European and Mediterranean populations.

HLA alleles have been determined for the first time in individuals from the Chuvashian population by DNA typing and sequencing. HLA-A, -B, -DR, and -DQ allele frequencies and extended haplotypes have also been determined, and the results compared to those for Central Europeans, Siberians and other Asians, Caucasians, Middle Easterners, and Mediterranean peoples. Genetic distances, neighbor-joining dendrograms, and correspondence analysis have been performed. Present-day Chuvash speak an Altaic-Turkic language and are genetically related to Caucasians (Georgians), Mediterraneans, and Middle Easterners, and not only to Central or Northern Europeans; Chuvash contain little indications of Central Asian-Altaic gene flow. Thus, present-day Chuvash who speak an Altaic-Turkic language are probably more closely related to ancient Mesopotamian-Hittites and northern European populations than to central Asia-Altaic people.

Europe↗
PubMed2000

[Parallel variation in mitochondrial DNA type 16278T in genome of the migrant population of Northeast Asia and other caucasoid populations].

Types of mtDNA with +16274EcoRV, which had been previously found in East Slavonic residents of Magadan, were identified on the basis of published data on nucleotide sequences of the hypervariable segment I (HVSI) of the mtDNA control region. These mtDNA types occurred in Slavs at a frequency of 7-14% and were assigned to four mitotype groups (1, 2A, 3B, and 5) restricted to Caucasoid populations. Regarding the evolution of mtDNA, this fact indicates that the C-T transition at position 16,278 arose independently in various groups of mtDNA types in Caucasoids. A new subgroup was isolated in Caucasoid group 5. One of the key mutations in this subgroup was variant +16398HaeIII (transition A-G at position 16,399), which was earlier detected in Russian populations at a relatively high frequency.

Asia↗
PubMed1992

[Population genetic Hae III/RFLP and HLA-DQ-alpha data of a Caucasian population sample in Switzerland].

DNA from unrelated individuals (Caucasians; n = 200-271) from Switzerland were digested with Hae III and successively hybridized to the DNA probes D1S7, D2S44, D4S139, D10S28, D14S13, D17S26 and D17S79. An allele frequency distribution was determined for each locus. Furthermore, from the same individuals (n = 200) after amplification of DNA the allele and genotype frequencies at the HLA-DQ alpha locus were determined. The allele frequency distribution in Swiss Caucasians is statistically similar to American Caucasian population samples. In criminal cases a DNA-profile derived from four single-locus probes always leads to a very high value of discrimination and in paternity testing the probability of paternity always exceeds 99.9% regardless to the reference population used for biostatistical evaluation. Therefore for use in forensic analysis and paternity testing pooled caucasian databases might be used for the determination of the frequency of occurrence of a DNA-profile.

Alleles↗
PubMed1992

[An increase in the knowledgeability of the population on the problem of arterial hypertension as a result of conducting a secondary prevention program in a nonorganized rural population].

The paper is concerned with evaluating the efficacy of sanitary and health measures carried out within the framework of the program of secondary prophylaxis of arterial hypertension (AH) in an open rural population in terms of changes in the information of the community about hypertension. The program included regular radio transmissions, talks and lectures pertaining to the problems of essential hypertension prevention and treatment. During 4 years, the information of the respondents about hypertensive action of table salt increased 4-fold (from 8 to 32.3%), especially among persons suffering from AH. The number of persons who referred to overweight as one of AH causes rose 6-fold (from 2.6 to 18.1%). The information did not depend on the sex, age, or the presence of hypertensive factors in the examinees. Alterations were recorded in the attitude of the examinees to AH and its treatment: the portion of those who took hypotensive drugs increased more than 2-fold (from 10.9 to 23.4%) whereas the percentage of subjects treated successfully from 6.8 to 10.1%. The data obtained attest to a high enough efficacy of sanitary and health measures in relation to AH in the rural population.

Adult↗
PubMedDate not supplied

[Population genetics of the 10 short tandem repeat (STR) loci in the population of Podlasie (Northeastern Poland)].

A population study on 10 STR loci: D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01 and FGA was performed on 620 unrelated individuals born in Podlasie (NE Poland). The DNA was amplified by multiplex PCR using a commercially available multiplex AmpFISTR SGM Plus kit. Capillary electrophoresis with fluorescent detection was carried out using the ABI 310 Genetic Analyzer. The expected performance of the analysed loci for personal identification and paternity testing was estimated. All loci met the Hardy-Weinberg assumption. No significant differences between the studied population and other Polish data were found. The combined values of the Matching Probability and of the Power of Exclusion are 4.18 x 10(-13) and 0.99997, respectively.

Adult↗
PubMed1977

[Medico-genetic study of the population of Uzbekistan. III. Phenotypical assortativity as a factor in population structure (using palmoplantar hyperkeratosis and vitiligo as examples)].

The article comprises the examples of homophenogamic marriages between persons with a rare hereditary dominant character, hand-palm and foot-sole hyperkeratosis, leading to the increase of inbreeding intensity in the population. On the contrary, homophenogamic marriages between persons with vitiligo, a considerably more widespread character, lead to the decrease of the degree of inbreeding in a population, since they take place between partners coming from different districts of the region.

Female↗
PubMed1978

[Physiological polymorphism in a population of the common frog. I. The polymorphism of a population of the common frog for the trait of muscle tissue heat resistance].

A study was made of heat resistance (36+/-0.2 degrees C) of m. interphalangealis of the third finger of a hind extremity in animals of one population of Rana temporaria L. living on the boundary between Leningrad region and Pskov region. Within this population, the existence of three groups of individuals differing in heat resistance levels of their m. interphalangealis is postulated. This conclusion is based on the distribution curve of heat resistance values and on the application of the probit-method. The distribution of the frequency of occurrence of individuals in these three groups follows Hardy-Weinberg's equation.

Animals↗
PubMed1979

[Population genetics of the population of the northern European RSFSR. III. Demographic and genetic characteristics of two rural communities of the Pinezhskii District of the Arkhangel'sk Region].

The paper deals with the distribution of genetic markers (systems ABO, Rh, Hp, PTC) and a number of phenotyping traits (folding of arms, hand clasping, tongue rolling, right- and left-handedness, the type of ear lobe, the types of dermatoglyphics patterns) in the inhabitants of 5 villages in the Pinezhsky district of the Arkhangelsky region of the RSFSR. The data presented in this work were obtained in the course of examination of over 900 persons. Among the systems analysed there was a statistically significant deviation from Hardy-Weinberg's equlibrium. It took place in two the least villages. In one case--for ABO blood groups, in another--for Hp system. There are an interesting fact of the excess of heterozygotes 2-1 and some excess of the group 0. Statistically significant differences between villages were shown for four genetic systems. Data on migrations, distribution of gene frequencies and estimated genetic and phenotype distances between villages of the same village community and between two communities suggest, that each village community can be considered as separate subdivided population. Considering the uniformity of the environmental pressure in the region examined, the heterogeneity of the population studied is apparently associated with a random genetic drift.

Blood Group Antigens↗
PubMed1991

[Genetics of the Caucasian population: Distribution of certain immunologic and biochemical markers in the Azerbaijanian and Armenian populations in the Georgian SSR].

Distribution of the genetic markers of blood groups (AB0, Rhesus, MNSs, Lewis, P, Kell-Cellano); serum proteins (Hp, C'3, Tf, Gc); red-cell enzymes (AcP, EstD,Glo-1) and also ABH-secretion was studied among three Azerbaijanian and two Armenian populations of the Georgian SSR. The results were used in analysis of the interpopulation variations and genetic relationship of the populations to their geographical neighbours.

Armenia↗
PubMed1990

[Genogeography of human populations: computer mapping of population genetics data].

Genogeography as a field of interdisciplinar investigation was introduced into science in 1928 by Russian geneticist A. S. Serebrovsky an today is well known in human genetics as gene geography. This work was undertaken to introduce a new method of computer cartography of gene frequencies in human and in any other populations. The method is different from known one of P. Menozzi, A. Piazza and L. Cavalli-Sforza. Two key moments of the method are principle of fusion-fission of gene in the homogeneous geographical space equally free-for-all human genes, and principle of local-linear (but not of the high-orders) interpolation of gene frequencies onto spheric surface of geographical space. Such procedure was used for mapping of human AB0-B gene frequencies among native populations of Central Asia.

ABO Blood-Group System↗
PubMed1989

[Natural microbial control of crickets populations (Orthoptera: Gryllotalpidae: Scapteriscus borellii): regulation of populations aggregated in time and space].

From 1983 through 1988, a total of 1,762 collections, containing 31,312 individuals of the mole cricket, Scapteriscus borellii, were made, principally in the State of São Paulo, Brazil. Collections were found to fit a negative binomial distribution both as whole and when divided into monthly collections. In these collections, an iridovirus, a entomogenous nematode, and the fungi Metarhizium anisopliae, Beauveria bassiana, Paecilomyces sp., and Entomophtora sp., were found to be agents of natural mortality, although usually as endozootics and relatively rarely as epizootics and panzootics. As a group, these diseases were also distributed in a binomial negative. These data suggest that the temporal and spatial aggregations of the mole crickets, produced by high rates of migration among suitable habitats, are adaptations to outbreaks of epidemics, which also serve as mole cricket population regulators. These ideas are develop and derived from simple mathematical models of population change.

Animals↗
PubMed1988

[Comparative studies of the population structure of a Kurd village population in Southeast Turkey. I. Morphologic regional comparison].

The paper is dealing with an anthropological investigation of a Kurdish village population from southern Turkey. We especially attached importance on the complete registration of all inhabitants to get a reliable sample for regional comparison of morphological features. Anthropological data of other Kurdish population groups are used for univariate and multivariate analysis. The resulting clusters are discussed beside the question of representation under the standpoint of regional and cultural origin of the samples.

Anthropometry↗
PubMed1987

[Genetic structure of aboriginal populations of northeastern USSR. VI. Correlations of genetic and geographic distances between populations and subpopulations].

Significant correlation of genetic distances (estimated for 17 polymorphic loci) between populations of Asia and Alaska Eskimos, coast and reindeer chuckchies, Kamchatka koryaks and Chuckotka even with geographic distances (r = 0.650; P less than 0.01) is shown. Also, significant correlation of genetic and geographic distances between 5 coast chuckchies subpopulations have been revealed (r = 0.871; P less than 0.001). The findings can indicate some ecological conditionality of population and subpopulation genetic structure's features.

Alaska↗