[Genetic demography of populations of three megalopolises in relation to the problem of creating genetic databases].

Based on data collected from urban residents by questionnaire, the basic parameters of the genetic-demographic structure of populations of the three megalopolises, i.e., Moscow, Kharkov, and Minsk, have been calculated, including the migration coefficients and their dynamics in generations, the radius of the cities migration attraction, the parameters of marriage structure (the proportion ofinterethnic marriages, the level of intraethnic assortative mating, the marital distances), and the gene flow between the ethnic groups. It is shown that the representatives of the most numerous ethnic groups in each megalopolis have considerable amount of admixture. For Russians of Moscow, Ukrainians of Kharkov, and Belarusians of Minsk, the proportion of individuals whose ancestors were all born in the given city for at least three generations and belonged to the same nationality turned out to be very low (4.75% in Moscow, 1.83% in Kharkov, and 3.13% in Minsk). This finding questions the formation of a reference population in the megalopolis as a sampling of aboriginals of certain ethnic origins. In the paper, we justify principles of creating genetic databases for the population of the megalopolis taking into account the complexity and dynamism of its population structure.

[Variation of the parameters of natural reproduction and Crow's indices in the ethnic groups of Dagestan].

Using the 2002 All-Russian population census data, the parameters of differential fertility as a component of natural selection (Crow's indices) have been calculated for women of seven age cohorts of the seven most numerous ethnic groups of the Republic of Dagestan. It has been shown that in the population of Dagestan in the second half of the 20th century the intensities of two types of selection tended to decrease, viz., intragroup selection relaxed in each ethnic group due to considerable reduction of interfamily variance in fertility and intergroup selection relaxed due to reduction ofinterethnic differences in fertility. A reduction of the average number of offspring (kappa) was observed in all ethnic groups, suggesting the spread of birth regulation practices (abortion and contraception). Nevertheless, all Muslim groups (aboriginal Dagestan ethnic groups and Azerbaijanis) are still characterized by an extended pattern of reproduction (2.7 < kappa < 3.3); in Russians kappa = 2.1. Interethnic differentials in natural reproduction rates, along with migration processes, account for the dynamics of the ethnic composition and gene-pool structure of the population of the Republic of Dagestan.

[Variation of morphophysiological and genetic demographic traits in children with congenital cleft lip and palate].

Medical records and questionnaire data have been used to analyze morphophysiological (the birth weight and length) and genetic demographic (maternal age and marriage structure) traits in a sample of children with orofacial malformations (OMs, cleft palate and/or cleft lip) living in Krasnodar krai, Russia. The sample of children with malformations (including premature infants) differs from the control group in lower birth weight and length and a lower proportion of children with morphophysiological values close to the population average values, as well as a higher family exogamy level estimated on the basis of marriage structure in the parental and preceding generations. The risk of congenital cleft palate and/or cleft lip is considerably increased if the material age is over 35 years or, to a lower degree, if it is under 20 years.

[Population genetic study of Russian cosmonauts and test subjects: genetic demographic parameters and immunogenetic markers].

Genetic demographic characteristics and immunogenetic markers (blood groups ABO, Rhesus, MNSs, P, Duffy, Kidd, and Kell) have been studied in a group of 132 Russian cosmonauts and test subjects (CTSG). Analysis of pedigrees has shown a high exogamy in the preceding generations: almost half of the subjects have mixed ethnic background. According to the results of genetic demographic analysis, a sample from the Moscow population was used as control group (CG). Comparison between the CTSG and CG has demonstrated significant differences in genotype frequencies for several blood group systems. The CTSG is characterized by a decreased proportion of rare interlocus genotypic combinations and an increased man heterozygosity. Analysis of the distributions of individual heterozygosity for loci with codominant expression of alleles has shown that highly heterozygous loci are more frequent in the CTSG. Taking into account that the CTSG has been thoroughly selected from the general population, it is concluded that heterozygosity is related to successful adaptation to a space flight.

[Genetic-demographic processes in the Moscow population in the mid 1990's. Analysis of ethnogeographic migration parameters (isolation by distance)]. / Genetiko-demograficheskie protsessy v moskovskoi populiatsii v seredine 90-x godov. Analiz étnogeograficheskikh parametrov migratsii: izoliatsiia rasstoianiem.

Geographic parameters of migration were analyzed on the basis of data on birthplaces of individuals who contracted marriages in Moscow 1955, 1980, and 1994 to 1995. It was shown that the relationship between the migration rate and distance significantly changed in the 1990s. Investigation of ethnic composition of migrants demonstrated that an increase of migration activity of residents of Transcaucasia and North Caucasus recorded in 1990s was associated with an increase in migration to Moscow of representatives of indigenous populations of these regions rather than with repatriation of Russians. Analysis of migration with the use of the Malecot's model of isolation by distance showed that genetically effective migration accounted for 1/7, 1/3, and 1/4 of the total marital migration rate in 1995, 1980, and 1990, respectively. An increase in mean migration distance in 1995 to 1980 is explained mainly by a decrease in the proportion of short-range migration. The level of isolation by distance was extremely low and showed a trend to further decrease during the 40-year time interval. Parameters of the model indicated that at present the population of the central part of the Moscow oblast in the 80-km zone from the city center should be assigned to the Moscow population.

[Genetic-demographic processes in the Muscovite population in the mid-1990s. Migration and emigration as a factor for changing the genetic diversity of the population]. / Genetiko-demograficheski protsessy v Moskovskoi populiatsii v seredine 1990-x godov. Migratsiia i émigratsiia kak faktora izmeneniia geneticheskogo raznoobraziia populiatsii.

On the basis of official migration statistics and marriage records, the genetic parameters of migration in the Moscow population over the past 120 years were determined. Although the number of officially registered migrants decreased, the coefficient of marriage migration in the mid-1990s was higher than in the mid-1980s (m = 0.4). The in-migrants considerably differed from Moscow-born residents with respect to their age at marriage, ethnicity, level of education, and speciality. The emigration of the Moscow residents to foreign countries was selective with respect to the educational level and adversely affected the labor, intellectual, and cultural resources of Moscow (the "braindrain"). In the long run, the observed ethnic differences between in-migrants and emigrants may considerably influence the ethnic composition and, hence, genetic diversity of the Moscow population.

[The role of migration processes in the formation of marriage structure of Moscow population. II. Assortative mating for the age, birthplace and nationality]. / Rol' migratsionnykh protsessov v formirovanii brachnoi struktury moskovskoi populiatsii. Soobshchenie II. Brachnaia assortativnost' v otnoshenii vozrasta, mest rozhdeniia i natsional'nosti suprugov.

Positive assortative mating for age at marriage, birthplace and nationality has been revealed by means of sample analysis of couples married in Moscow in 1955 and 1980. The correlation coefficient between mates for age at marriage was r = 0.81 in 1955 and r = 0.88 in 1980; the age difference between spouses had a mean of 1.55 and 2.21 years, respectively. The determinative role of migration in forming Moscow population marriage structure accounts for the fact that the greater part of marriages registered in the capital are between migrants from various regions of the USSR or between the Moscow-born and the migrants. The proportion of marriages between individuals born in Moscow has increased over 25 years from 10 to 38%, these values being significantly higher than those expected under random mating between the migrants and the Moscow-born. The contingency coefficient measuring the association between the birthplaces of husband and wife was K = 0.16 in 1955 and K = 0.11 in 1980, the preferential marriage between mates born in the same region being still significant even when marriages are registered in Moscow. The highest degrees of assortative mating were observed for nationality character: K = 0.37 in 1955 and K = 0.28 in 1980. The decrease in these values over the past 25 years has resulted in a slight growth of the proportion of international marriages (from 14.75 to 16.53%) which has not yet reached the level expected under panmixia (about 21%).

[The role of migration processes in the formation of the marriage structure of Moscow population. III. Assortative mating as a factor counteracting the outbreeding]. / Rol' migratsionnykh protsessov v formirovanii brachnoi struktury moskovskoi populiatsii. Soobshchenie III. Brachnaia assortativnost' kak faktor, protivodeistvuiushchii autbridingu.

The genetic consequence of positive assortative mating for the demographic characters in the megapolis population is being discussed.

[Role of migration processes in shaping the marriage structure of the Moscow population. I. The age, place of birth and nationality of those entering marriage]. / Rol' migratsionnykh protsessov v formirovanii brachnoi struktury moskovskoi populiatsii. Soobshchenie I. Vozrast, mesto rozhdeniia i natsional'nost' vstupaiushchikh v brak.

A genetic-demographic study of the dynamics of the Moscow population marriage structure, with respect to the age of marriage, birthplace and nationality of newlyweds has been carried out by means of sample analysis of 1955 and 1980 marriage records; some other demographic and statistic data obtained during several years were also used. The mean age of marriage being practically constant, the proportion of newlyweds younger than 20 in the reproductive part of the Moscow population was shown to be considerably higher at the beginning of the XX century than at present. The number of couples married at the postreproductive age increased in 1980, as compared with 1955. The process of migration contributing to the genetic structure of subsequent Moscow generations has been characterized quantitatively and from the spatio-geographical point of view. High values (0.57 less than m less than 0.86) of the coefficient of migration to Moscow correspond to the period of non-controlled city population growth. As a result of administrative measures for regulation of the city population growth, the value of the coefficient of migration to Moscow decreased considerably by 1980, though still remained at a rather high level (m=0.40). The mean migration distance increased from 230 km, in the beginning of XIX century to 560 km in 1955 and 1100 in 1980. Especially great was the increase of genetic contribution from Eastern and Southern regions of the USSR. The variability of the national composition also increased. These changes in the geography of migration will cause the increasing reproduction of the entire country gene pool in Moscow as a panmixia center that may result in genetic originality of the Moscow population.