Genetic structure of the population of Ashkhabad City of the Turkmen SSR]

Some genetical demographic characteristics of population of Ashkhabad city were studied by direct interviewing of women aged over 18 years. The influence of urbanization on the basic genetical-demographic indices was found, the indices being essentially different from those of rural population studied elsewhere. Analysis of intensity and the structure of marriage migrations showed considerable ethnic subdivision in Ashkhabad population and stability of marriage policy in an every ethnic group. The level and structure of inbreeding as well as positive marriage assortativity are of the same order as in the Turkmen rural population.     

Hereditary Diseases of Nervous System in the Population of Vladimir Oblast

The first population genetic study of hereditary disorders of the nervous system (HDNS) in Vladimir oblast was carried out. A total of 1622900 subjects, including 1306200 from the urban and 316700 from the rural population, were tested. The population examined was characterized by virtually homogenous ethnic structure, with Russians constituting 95.76%. Pooled prevalence of HDNS in Vladimir oblast corresponded to the average prevalence for other Russian populations. Substantial differences between urban and rural populations in respect of the population load of HDNS and its nosological structure were not observed. A total of 22 nosological forms of HDNS were revealed, including thirteen autosomal dominant (193 families with 272 affected individuals), seven autosomal recessive (59 families with 66 affected individuals), and two X-linked (15 families with 17 affected individuals) diseases. The composition of the HDNS spectrum nucleus in Vladimir oblast displayed a number of differences from that in the majority of other populations examined. The HDNS in different regions of the area tested were characterized by different prevalence and spectrum. The data obtained may constitute a basis for regional registration of HDNS in Vladimir oblast.     

Dynamics of the Genetic Demographic Structure of the Kursk Oblast Population: Migration Processes

Marriage records from parish books of the second half of the 19th century and marriage records of 1967–1970 and 1993–1995 obtained from registry offices were used to analyze the dynamics of genetically significant parameters of migration and marriage structure with respect to spouses' birthplaces in populations of different hierarchical levels in the Kursk oblast. It was found that, among the persons contracting marriage (both males and females), the proportions of those who were born in the same population and those who were born in any population of the Kursk oblast decreased by about one third and one fifth, respectively, for the 130-year period. In rural and small urban populations, the coefficients of marriage migration in the 19th century were an order of magnitude lower than in the 20th century. The immigration to urban populations was maximum in the late 1960s (m = 0.745 in small towns and m = 0.680 in Kursk), and that to rural populations, in the 1990s (m = 0.344). In both urban and rural populations, the mean distance between the spouses" birthplaces has increased by several times for the period studied. The endogamy level has decreased approximately twofold: from 0.797 to 0.380 in Kursk, from 0.897 to 0.419 in small towns, and from 0.958 to 0.440 in rural districts. The marriage assortativeness with respect to birthplace was maximum in the late 19th century (K = 0.393–0.491) and minimum in the 1960s (K= 0.155–0.246). The increase in genetic diversity of the urban population of the Kursk oblast due to migration has been slowing down since the late 20th century, whereas the outbreeding level is still increasing in rural populations.     

Hereditary diseases of nervous system in the population of Vladimir province

The first population genetic study of hereditary disorders of the nervous system (HDNS) in Vladimir oblast was carried out. A total of 1,622,900 subjects, including 1,306,200 from the urban and 316,700 from the rural population, were tested. The population examined was characterized by virtually homogenous ethnic structure, with Russians constituting 95.76%. Pooled prevalence of HDNS in Vladimir oblast corresponded to the average prevalence for other Russian populations. Substantial differences between urban and rural populations in respect of the population load of HDNS and its nosological structure were not observed. A total of 22 nosological forms of HDNS were revealed, including thirteen autosomal dominant (193 families with 272 affected individuals), seven autosomal recessive (59 families with 66 affected individuals), and two X-linked (15 families with 17 affected individuals) diseases. The composition of the HDNS spectrum "nucleus" in Vladimir oblast displayed a number of differences from that in the majority of other populations examined. The HDNS in different regions of the area tested were characterized by different prevalence and spectrum. The data obtained may constitute a basis for regional registration of HDNS in Vladimir oblast.     

Population and demographic study of the Turkmen Tekke

Genetical and demographic studies of typical rural population of Turkomen teke in Yangi-Kala village of the Ashkhabad region (about 5.000 inhabitants) were performed through the examination of a sample of 3528 persons. The population is characterised by intensive growth (mean number of children per one woman is 6.17), a high level of endogamy (the total coefficient of inbreeding being 0.010912), preserving the traditional marriage system (91.9 and 8.1% of intrageneric and intergeneric marriages, respectively). Migration does not significantly influence endogamy, because it takes place among kin families.     

Dynamics of the genetic demographic structure of the Kursk province population: migration processes

Marriage records from parish books of the second half of the 19th century and marriage records of 1967-1970 and 1993-1995 obtained from registry offices were used to analyze the dynamics of genetically significant parameters of migration and marriage structure with respect to spouses' birthplaces in populations of different hierarchical levels in the Kursk oblast. It was found that, among the persons contracting marriage (both males and females), the proportions of those who were born in the same population and those who were born in any population of the Kursk oblast decreased by about one third and one fifth, respectively, for the 130-year period. In rural and small urban populations, the coefficients of marriage migration in the 19th century were an order of magnitude lower than in the 20th century. The immigration to urban populations was maximum in the late 1960s (m = 0.745 in small towns and m = 0.680 in Kursk), and that to rural populations, in the 1990s (m = 0.344). In both urban and rural populations, the mean distance between the spouses' birthplaces has increased by several times for the period studied. The endogamy level has decreased approximately twofold: from 0.797 to 0.380 in Kursk, from 0.897 to 0.419 in small towns, and from 0.958 to 0.440 in rural districts. The marriage assortativeness with respect to birthplace was maximum in the late 19th century (K = 0.393-0.491) and minimum in the 1960s (K = 0.155-0.246). The increase in genetic diversity of the urban population of the Kursk oblast due to migration has been slowing down since the late 20th century, whereas the outbreeding level is still increasing in rural populations.     

Burden of monogenic hereditary pathologies of the residents of Ashkhabad in the Turkmen SSR]

The results of medico-genetic investigation of population of Ashkhabad city are presented involving 229 thousand individuals (118230 Turkomans, 94050 Russians and 16720 subjects of other nationalities). Aggravation values the ethnic groups studied are as follows: Turkomen--AD (autosome-dominant = 0.86 per 1000 subjects, AR (autosome-recessive) = 2.31 per 1000 subjects, attached X chromosomes = 0.52 per 1000 males; Russians--AD = 0.93 per 1000 subjects, AR = 0.84, attached X chromosomes = 0.17 per 1000 males; other nationalities AD = 0.81, AR = 1.43, attached X chromosomes = 0.27. Aggravation of the urban Turkomen population is more valid than that of rural people. Relationship between non-accidental inbreeding rate and aggravation with autosome-recessive pathology is shown for several ethnic subdivisions of the population studied.     

Medical genetic study of the population of Turkmenia. III. Hereditary pathology in Turkmen Nokhurlis

Medical-genetic investigations were carried out in isolated population of Nokhurlis inhabiting some villages of Ashkhabad and Krasnovodsk provinces. A high coefficient of inbreeding, high endogamy, and low coefficients of migration were found for this population. Two hereditary disorders are relatively frequent among the Nokhurlis and lacking in neighboring populations. The frequency of the autosomal dominant gene for congenital cataract is 0.26% and that of the autosomal recessive gene for a peculiar form of obesity is 2.47%. In both cases, the main factor affecting gene accumulation appears to be the result of genetical drift effect. The total load of hereditary diseases of higher in Nokhurlis than in other Turkmen populations. The connection between the population structure of Nokhurlis and the accumulation of hereditary disorders is discussed.     

Genetic dissection of interactions between wheat flour starch and its components in two populations using two QTL mapping methods

Starch content and its components are important for determining wheat end-use quality and yield. However, little information is available about their interactions at the QTL/gene level in more than one population using different QTL mapping methods. Therefore, to dissect these interactions, two mapping populations from two locations over 2 years were used. The QTLs for the populations were analyzed by unconditional and conditional QTL mapping by two different analysis methods. In the two populations, there were a total of 24 unconditional additive QTLs detected for flour amylose (FAMS), flour amylopectin (FAMP), flour total starch (FTSC), and the ratio of FAMS to FAMP using ICIMapping4.1 methods, but 26 unconditional QTLs were found using QTLNetwork2.0 methods. Of these QTLs, 10 stable major additive QTLs were identified in more than one environment, mainly distributed on chromosomes 3B, 4A, 5A, and 7D. The maximum percentage of phenotypic variance explained (PVE) reached 54.31%. Two new unconditional major additive QTLs on chromosome 3B (Qftsc3B and Qfamp3B) were found. A total of 23 and 19 conditional additive QTLs were identified in the two populations using two different methods, respectively. Of which, eight and six stable major conditional QTLs were detected on chromosomes 3B, 4A, and 7D, respectively. New repressed QTLs were identified, such as Qftsc/fams5B-1 and Qftsc/fams5B-2. There were 20 epistatic unconditional and 15 conditional QTLs detected. In all, important QTLs on chromosomes 3B, 4A, and 7A were found in both populations. However, the number of important QTLs in the special recombinant inbred line (RIL) population was higher than that in the double haploid (DH) population, especially on chromosomes 7D and 5B. Moreover, the QTLs on chromosomes 4A, 7A, and 7D were close to the Wx-1 loci in the RIL population. These indicated better results can be obtained by a special population to target traits than by a common population. The important QTLs on key chromosomes can always be detected no matter what kinds of populations are used, such as the QTLs on chromosome 4A. In addition, QTL clusters were found on chromosomes 4A, 3B, 7A, 7D, and 5A in the two populations, indicating these chromosome regions were very important for starch biosynthesis.     

Mutagens in the feces of 3 South-African populations at different levels of risk for colon cancer.

The incidence of mutagens in the feces of 3 South-African populations at different risk levels for colon cancer has been determined. Lyophilized fecal samples were extracted with ether and the mutagenicity of the extracts determined using the Salmonella/mammalian microsome mutagenicity test. 19% of the samples from urban white South-Africans, a population at a high risk for colon cancer, were mutagenic using Salmonella typhimurium strain TA100. This incidence was significantly greater (p less than 0.001) than the incidence of mutagen excretion in the low-risk populations of urban blacks (2%) and rural blacks (0%). This pattern was also obtained using Salmonella typhimurium strain TA98. The incidence of mutagen excretion for urban whites was 10%, as compared to 5% and 2% for urban and rural blacks, respectively.     

Dynamics of microbial populations in soil: Indigenous microorganisms degrading 2,4-dinitrophenol

The mineralization of 2,4-dinitrophenol (DNP) and changes in the DNP-mineralizing population over a wide range of DNP concentrations were monitored to evaluate the dynamics of the DNP-mineralizing populations in two soils (soils 1 and 2). Curves of CO₂ evolution were analyzed using nonlinear regression analysis and models incorporating parameters for population size and growth rate. The results of these analyses were compared to independent estimates of the DNP-mineralizing population from most-probable-number (MPN) determinations. The combined results of these analyses showed that 0.1g of DNP g^–1 of soil was too low a concentration to support maintenance or growth of the DNP-mineralizing population, whereas all higher concentrations supported either maintenance or growth of the population in soil 1. Independent estimates of population size showed good agreement between the nonlinear regression and MPN techniques, especially at initial DNP concentrations below 100g g^–1. Estimates of both population size and maximum specific growth rate varied with concentration, possibly indicating the existence of two different DNP-mineralizing populations in soil 1. In the other soil tested (soil 2), the population of DNP-mineralizers was much lower than in the first soil, and no evidence of two populations was obtained. In soil 2, good agreement between the nonlinear regression and MPN estimates of population size was also obtained. Results of this study demonstrate the power of using testable models of population dynamics to obtain useful estimates of parameters of microbial growth and survival in soil.     

Marital and migration structure and inbreeding in the Adyg population]

Endogamy and gametic indices for both Russian and Adyg populations living in the Adyg autonomous region of Krasnodar district were determined on different levels of territorial units: village, rural, community (a group of villagers) and rural region. Inbreeding coefficient was estimated for Adyg population and its structure analysed: a random component contributes mostly to the inbreeding coefficient (Fst = 0.00991), non-random component of the inbreeding coefficient being Fis = 0.010009, which testifies to negative marital assortativity among Adygs. Local inbreeding "a" and decline in the inbreeding "phi" coefficient at a distance from 0 to 500 km were calculated using the Malecot's formula: the coefficient "a" was found to be 0.00397, which is in good accordance with the Fst.     

Genetic demographic study of shors in Tashtagolskii raion of Kemerovo oblast: Population dynamics and changes in the sex and age composition

The population dynamics and changes in the sex and age structure of the Shor populations of four rural district municipalities of Tashtagolskii raion of Kemerovo oblast (Kyzyl-Shorskii, Ust-Anzasskii, Ust-Kolzasskii, and Ust-Kabyrzinsskii) with time have been analyzed. The Shor populations have been found to have contained a high proportion of people under 18 years of age during two periods, 1940–1955 and 1970–1975 (38.12–46.38 and 40.98–54.97%, respectively). However, the population reproduction pattern changed into the “reduced” one in all the municipalities studied by the early 2000s. Although there are some regional variations, a common trend towards rural population aging has formed: the man age in the Tashtagolskii raion population has increased by 7.52 and 6.94 years for men and women, respectively, during two generations; the natural sex ratio has been disturbed in both the prereproductive and reproductive populations. The total population size and effective reproductive size have decreased in three out of the four rural subpopulations studied.     

Genetic analysis assessed by microsatellites for a diallel mating design of two geographical stocks of the blood clam <Emphasis Type="Italic">Tegillarca granosa</Emphasis>

To determine the potential for productive efficiency and genetic improvement in the blood clam Tegillarca granosa, four offspring populations (ZZ, ZK, KZ and KK) were produced from a diallel mating of two different geographical stocks (Z and K). The levels of genetic diversity and population structures of four populations were analyzed using 14 polymorphic microsatellites. The results showed that the mean observed heterozygosities (Ho) of reciprocal cross populations (ZK and KZ) was higher than those of pure populations(ZZ and KK). The largest values of genetic differentiation coefficient (F_st?=?0.067) and Nei’s unbiased genetic distance (Dc?=?0.263) were between ZK and KZ, and the smallest (F_st?=?0.020, Dc?=?0.116) were between ZZ and KK, which revealed that the largest genetic divergence was between the two reciprocal cross populations and the smallest was between two pure populations. This study demonstrated that the reciprocal cross populations of T. granosa had an extensive genetic difference and improvement, which may be advantageous for future breeding studies.     

Reproductive compensation in human populations

Reproductive compensation was studied in Russian (family planning) and Middle-Asian (with natural reproduction) urban and rural populations. Questionnaires were used describing postreproductive-age women having at least one pregnancy. The presence of reproductive compensation in a population was identified by comparison of two groups: "loaded" and "unloaded" by values of total and effective fertility. Families with excessive (compared with the mean population value) pregnancy outcome failure (spontaneous abortions, stillbirths, preproductive-age deaths of children) were ascribed to the loaded group. Reproductive compensation was discovered in all populations studied, which indicates that this phenomenon is wide-spread in human populations.     

Epidemiology of monogenic hereditary diseases in Rostov oblast: Population dynamic factors determining the differentiation of the load of hereditary diseases in eight districts

A genetic epidemiological study has been carried out in eight raions (districts) of Rostov oblast (region) of Russia: Tsimlyansk, Volgodonskoi, Tselina, Egorlykskaya, Millerovo, Tarasovskaya, Rodionovo-Nesvetaiskaya, and Matveevo-Kurgan raions. The population structure (the parameters of the isolation by distance model, ethnic assortative marriage, random inbreeding (F _ST), endogamy index, and ie) and the genetic demographic characteristics of the regional population (vital statistics, Crow’s index, and its components) have been analyzed. The total sample size was 320 925 subjects (including 114 106 and 206 816 urban and rural residents, respectively). The load of the main types of Mendelian diseases (autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases) has been calculated for the total sample from eight districts and separately for the urban and rural populations. Substantial differences between individual districts in the AD and AR genetic loads have been found, especially upon separation into urban and rural samples. The results of correlation analysis suggest that migration and genetic drift are the main factors of genetic differentiation of populations with respect to the prevalence of hereditary diseases.     

Historical diversification of a terra-firme forest bird superspecies: a phylogeographic perspective on the role of different hypotheses of Amazonian diversification

Among those few hypotheses of Amazonian diversification amenable to falsification by phylogenetic and population genetics methods, three can be singled out because of their general application to vertebrates: the riverine barrier, the refuge, and the Miocene marine incursion hypotheses. I used phylogenetic and population genetics methods to reconstruct the diversification history of the upland (terra-firme) forest superspecies Xiphorhynchus spixii/elegans (Aves: Dendrocolaptidae) in Amazonia, and to evaluate predictions of the riverine barrier, refuge, and Miocene marine incursion hypotheses. Phylogeographic and population genetics analyses of the X. spixiilelegans superspecies indicated that the main prediction of the riverine barrier hypothesis (that sister lineages occur across major rivers) hold only for populations separated by "clear-water" rivers located on the Brazilian shield, in central and eastern Amazonia; in contrast, "white-water" rivers located in western Amazonia did not represent areas of primary divergence for populations of this superspecies. The main prediction derived from the refuge hypothesis (that populations of the X. spixii/elegans superspecies would show signs of past population bottlenecks and recent demographic expansions) was supported only for populations found in western Amazonia, where paleoecological data have failed to support past rainforest fragmentation and expansion of open vegetation types; conversely, populations from the eastern and central parts of Amazonia, where paleoecological data are consistent with an historical interplay between rainforest and open vegetation types, did not show population genetics attributes expected under the refuge hypothesis. Phylogeographic and population genetics data were consistent with the prediction made by the Miocene marine incursion hypothesis that populations of the X. spixii/elegans superspecies found on the Brazilian shield were older than populations from other parts of Amazonia. In contrast, the phylogeny obtained for lineages of this superspecies falsified the predicted monophyly of Brazilian shield populations, as postulated by the Miocene marine incursion hypothesis. In general, important predictions of both riverine barrier and Miocene marine incursion hypotheses were supported, indicating that they are not mutually exclusive; in fact, the data presented herein suggest that an interaction among geology, sea level changes, and hydrography created opportunities for cladogenesis in the X. spixii/elegans superspecies at different temporal and geographical scales.     

Genetic demographic study of an urban sample of Turkmen-teke with behavioral abnormalities

Genetic and demographic studies of urban sample of Turkmen-teke (Ashkhabad city) were performed among probands-36 patients with diagnosis of "schizophrenia" and their 840 relatives. Clinical analysis revealed 27.8% of phenocopies. In other 26 families the genealogical analysis showed autosomal-dominant (12 families), probably, autosomal-dominant (9 families) as well as autosomal-recessive (3 families) types of inheritance of pathology, in two families the type being not established. The empiric risk of affection was determined to be 24.2% for parents, 75.5% for sibs and 33.3% for children. Mean number of children per one woman is 3.53, which is significantly lower than mean populational number (6.17). High level of endogamy of the urban sample tested is established, the total coefficient of inbreeding being 0.009856; grandparents of the probands appeared to be exclusively of rural origin. The negative action of selection (decreased fitness), preferentially monogenic type of heredity and high level of endogamy are discussed as factors providing broad hereditary heterogeneity of schizophrenia.     

Host Differences among Florida Populations of Belonolaimus longicaudatus Rau

Three populations of Belonolaimus longicaudatus from Gainesville, Fuller''s Crossing, and Sanford, all in Florida, were tested for parasitism on Citrus jambhiri (rough lemon), Arachis hypogaea (''Early Runner'' peanut), Fragaria sp. (''Florida 90'' hybrid strawberry), and Lycopersicon esculentum (''Rutgers'' tomato). The three populations were found to be three different physiological races because: (i) the Fuller''s Crossing population reproduced well on and caused injury to rough lemon and tomato but not strawberry; (ii) the Gainesville population reproduced well on and caused injury to peanut, strawberry and tomato but not on rough lemon; (iii) the Sanford population reproduced well on and caused injury to peanut, reproduced well on tomato, but neither reproduced upon nor caused injury to strawberry or rough lemon. Morphologically, females of the Sanford population have a lower "c" value and a greater number of tail annules than those of the Gainesville and Fuller''s Crossing populations. Females and males of the Fuller''s Crossing population had higher "a" values than those of the other two populations.     

Do sexual pheromone traps provide biased information of the local gene pool in the pine processionary moth?

Abstract 1 Sexual pheromone traps are commonly used to monitor populations of the pine processionary moth, Thaumetopoea pityocampa, assuming that trapped males are representative of the breeding population. 2 For seven Italian populations, mitochondrial haplotypes (COI and COII) of adult males caught in traps were compared with those of larvae obtained from egg batches laid in the same year, to test whether the males trapped were representative of the local populations. 3 The distribution of haplotype frequencies revealed substantial homogeneity between adult males and larvae samples from the same population, except for Aosta Ruines Verrès, a population recently expanding in the south‐western Alps. In this case, the results suggested that trapped males were recruited over a wider area than local moths because haplotype diversity was higher than that of larvae. 4 A further analysis of this population using nuclear markers (AFLP) confirmed that adults, collected in pheromone traps, were genetically different from the larvae emerging in the same stand. 5 In conclusion, the assumption that trapped males are representative of breeding populations was confirmed for core populations, but has not been verified for the recently established population of Aosta Ruines Verrès. This should encourage discussion with respect to the reliability of pheromone traps in monitoring programmes of the pest, especially at the range's edge.