Population genetics of the people of Iran II. Genetic differentiation and population structure

The genetic structure of six populations of Iran (Turks, Kurds, Lurs, Zabolis, Baluchis and Zoroastrians) was examined using data on blood groups, serum proteins and cell enzymes. Our results show conclusively that there are genetic differences among the six populations and the analysis of superimposed R and S matrices defined Harpending & Jenkins (1973) show by that the dispersion of some of the alleles correspond to the dispersion of the populations. The F_ST estimates are not large enough to favour selection on any of the loci studied. The F_IT and F_IS estimates are positive and moderately high suggesting that the genetic differentiation to some extent is influenced by inbreeding.     

Population genetics of chimpanzee blood groups

A series of 60 chimpanzees (Pan troglodytes) were tested for their human-type A-B-O blood groups and for ten simian-type blood factors. Of the 60 chimpanzees four were group O and 56 group A; combining this with our previous results, among 274 chimpanzees there were 36 group O and 238 group A. Gene frequency analysis of the V-A-B types (determined by three antisera, anti- V ^c, anti- A ^c and anti- B ^c) of the 60 chimpanzees indicated inheritance by four allelic genes, namely, the amorphic gene v and the three additional alleles v^A, v^B and V. This theory allows for the existence of ten genotypes but only seven V-A-B phenotypes, since the type V.AB is excluded. Gene frequency analysis confirmed that C^c and c^c are contrasting antigens determined by corresponding allelic genes. The distribution of the C-c-E-F types among the 60 chimpanzees, as well as among 133 chimpanzees previously tested, is compatible with the postulation of five allelic genes, namely, the amorph c, and the alleles C^E, C^F, C^EF and the very rare allele C. The blood factor G ^c appears to define a separate blood group system, independent of the V-A-B and C-E-F systems. The newly defined blood factor Lindsay appears to be related to the V-A-B system, while factor H ^c may be related to the C-E-F system.     

Genetic studies in Saudi Arabia: red cell enzyme, haemoglobin and serum protein polymorphisms.

Population genetic studies in Saudi Arabia are performed for EsD, GPT, AcP, ADA, AK, 6-PGD, PGM, C3, Tf, Hp, Gc, Pi, Bf, Hb, ABO-blood groups and Rh-factor, level of the third component of complement and immunoglobulins. The data are compared with reported frequencies in European and African populations.     

Genetic studies in Ecuador: Acetylator phenotypes,red cell enzyme and serum protein polymorphisms of Shuara Indians

Population genetic studies of Shuara Indians in Ecuador are performed for GPT, AP, PGM₁, Ak, EsD, 6-PGD, Hp, Gc, C3, Bg, ChE, Tf, Pi, Bf phenotypes, IgG, IgA, IgM, C3, C3-proactivator, C4 levels and acetylator phenotypes. Some systems having a polymorphism in many other populations showed a lack of some of those alleles in the population under study (C3, ChE, Tf, AK and almost absent 6-PGD, Bg, Bf).     

Genetic studies of free-ranging macaques of Cayo Santiago. I. Description of the population and some nonpolymorphic red cell enzymes.

Phenotypes of eight red cell enzymes at nine genetic loci were determined in the semi-free-ranging population of rhesus macaques; Macaca mulatta, that inhabit Cayo Santiago. The following enzymes were examined electrophoretically: adenosine deaminase, glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, indophenol oxidase, lactate dehydrogenase, malate dehydrogenase, phosphoglucomutase-1, phosphoglumutase-2, and purine nucleoside phosphorylase. Hemolysates from at least 372 animals were analyzed, and no variants of the enzymes were observed with the exception of malate dehydrogenase. Three animals displaying a variant form of malate dehydrogenase were found.     

Genetic systems of red cell blood groups in goats.

Evidence is presented for six genetic systems of goat red cell blood groups. The A system presently consists of one specificity, two alleles, two phenotypes (A1 and no-A1) and appears to be homologous to the A system of sheep. The B system, like its homologue in sheep, is very complex. Fourteen of 21 specificities detected in the present study, i.e. B2, B3, B4, B5, B7, B8, B9, B10, B11, B14, B15, B16, B17 and B20, belong to the B system which involves a large number of phenogroups (31 different B phenogroups identified in 26 sires). Because of their homology with sheep C and R systems, two other genetic systems of goat blood groups are named C and R respectively. Each of the two goat systems is presently a one blood group specificity, two phenotype (C12 and no-C12; R and no-R detectable on the red cells) two allele system. Two specificities, namely E6 and E18, belong to a genetic system called E in which four phenotypes are under the control of two alleles codominant and one recessive at a single locus. The F system involves but a single pair of alleles and two phenotypes (F19 and no-F19). Because of its low frequency in the goats tested, the X13 specificity remains unassigned.     

Blood groups, serum proteins, and red cell enzymes in the Nganasans (Tavghi)-reindeer hunters from Taimir Peninsula

The Nganasans are made up of two recently tribal populations. These, the Avam and Vadey, were established in the seventeenth century from small reindeer hunting bands, themselves apparently descended from the Yukaghir. Data on 13 blood systems have been described for the first time in the Vadey Nganasans, and the results compared with those previously reported for the two Avam subgroups. As a whole, the Nganasans are characterized by low frequency of B blood group, high frequencies of Ns, cDE, Fy(a), Hp(2), absence of A2, P(c), K, and apparently an absence of cde alleles or haplotypes. Measurement of intrapopulation heterogeneity reveals significant divergence among the two Avam subdivisions (chi 2/16=57.59; P less than 0.001), as well as between the total Avam and Vadey (chi 2/17=79.31; P less than 0.001). Founder principle, and local genetic drift, are believed to account for the greater difference between the Avam and Vadey subgroups than that observed between the two Avam populations. The Nganasans of the Taimir Peninsula appear to be the last group of reindeer hunters remaining in Northern Siberia. For ages they have lived in relative isolation, and therefore are the least touched genetically, either by surrounding herding groups originating in Southern Siberia, or by recent Caucasian admixture.     

Blood group antigens and the population genetics of Macaca mulatta on Cayo Santiago. I. Genetic differentiation of social groups

The red blood cell phenotypes for eight polymorphic loci were determined for 293 free-ranging Macaca mulatta living on Cayo Santiago; this number represents the total population of the island, disposed in four social groups plus peripheral males. The rhesus population shows significant genetic heterogeneity over blood group systems (loci) and social groups. No particular genetic locus or social group is solely responsible for the genetic heterogeneity observed. The distributions of genotypes for two loci (G and H) do not deviate significantly from Hardy-Weinberg expectations within social groups or in the population as a whole. Correction of the equilibrium expectations for the effect of population subdivision yields no statistically significant results. Overall, the results suggest that the interaction of a variety of processes (random genetic drift, founder effect, migration and selection) may be responsible for the diversity observed. These data, combined with those from further studies, may allow an application of behavioral and genetic knowledge to the study of microevolutionary processes among nonhuman primates.     

Genetic study in Greek Sarakatsans. I. Blood groups and enzyme polymorphisms

A random sample from the endogamic population of Greek Sarakatsans has been studied for eight blood groups, eleven enzymic genetic systems and haemoglobin variants. The allelic frequencies of the polymorphic loci have been compared with those of other samples from the Greek mainland and other European populations. The Sarakatsans tend to resemble their neighbours. The comparison with European populations indicates that the Sarakatsans have gene frequencies similar to other Mediterranean and European populations. However, the monomorphism of the Kell system, the low frequency of the ACP^*B, AK^*1 and GLO^*1 allelas and the high frequency of the ACP^*C, ESD^*1 and GPT^*1 alleles, are some of the distinguishing features of Sarakatsans. Furthermore, the Sarakatsans are not a high risk population for G6PD deficiency and haemoglobinopathies.     

Genetic studies of human apolipoproteins. XVII: Population genetics of apolipoprotein polymorphisms in American Samoa

Variation in human apolipoprotein genes is a major source of phenotypic differences in human lipid metabolism. Data regarding genetic variation at apolipoprotein loci in various populations are only beginning to accumulate, and they suggest that different populations vary widely in distribution of apolipoprotein alleles. Using isoelectric focusing-immunoblotting techniques, we screened 67 serum samples from self-identified Samoan residents of American Samoa to investigate structural variation at six apolipoprotein loci: A-I, A-II, A-IV, C-II, E, and H. The APO A-I, A-II, and C-II loci were found to be monomorphic by isoelectrical focusing. In Samoans, the common three-allele polymorphism was observed for APO E, with no striking differences in frequencies from Caucasian populations. The three common alleles of the APO H locus also were identified; however, frequencies of the less common alleles (APO H*I and APO H*3) were different from those observed elsewhere for Caucasians.     

Population study of electrophoretic polymorphisms of red cell enzymes and plasma proteins in Caucasian Canadians

Blood samples from a random series of Canadian Caucasians were phenotyped for 28 red cell enzyme systems and eight plasma protein systems. Polymorphism was found in 17 and rare variants in 11 of the systems. Allele frequencies are presented for these; distribution of phenotypes is in accordance with the Hardy--Weinberg equilibrium theory. In a complementary study of families there was no evidence of de novo mutation in any of the 36 systems and they allowed a minimum estimate of the frequency of null alleles in the ADA, C2, and GPT systems.     

Reindeer Chukchi and Siberian Eskimos: Studies on blood groups,serum proteins,and red cell enzymes with regard to genetic heterogeneity

Phenotype and allelic frequencies for ABO, MNSs, P, Rh, Kell, Duffy, and Diego blood groups, as well as for transferrins (Tf), haptoglobins (Hp), phosphoglucomutase 1 (PGM₁), adenylate kinase (AK), 6-phosphogluconate dehydrogenase (PGD), and acid phosphatase (AcP) are described in 9–10 adjoining populations of Reindeer Chukchi. Additionally, one of three presently existing territorial subgroups of Siberian Eskimos was studied. The total sample size ranges from 931 to 1,066 in Chukchi, and from 99 to 102 in Eskimos, depending on the genetic system studied. Substantially reduced samples for Kidd and ABO secretion were investigated solely in the Reindeer Chukchi. Significant heterogeneity of allelic frequencies has been observed among Chukchi populations (χ = 378.47, P < 0.001). Summed genetic heterogeneity between Reindeer Chukchi and Siberian Eskimos was also found to be highly significant (χ = 186.54, P < 0.001). Both groups can be readily discriminated with only four outliers: NS , P¹, R¹, and P^a. Random genetic drift is suggested to be responsible for a large proportion of heterogeneity of allelic frequencies at the MNSs, P, and Rh blood-group system sites both among the Chukchi and Eskimos. Conversely, stabilizing selection is assumed as the principal agent maintaining homogeneous allelic frequencies at the AcP locus within the Chukchi subdivisions, whereas disruptive selection may be considered as a major factor leading to different p^a frequencies between Chukchi and Eskimos.     

Genetic polymorphisms of <Emphasis Type="Italic">XRCC1</Emphasis> (at codons 194 and 399) in Shiraz population (Fars province,southern Iran)

Objective Several potential functional polymorphisms in the DNA base excision repair gene X-ray repair cross-complementing group 1 (XRCC1) have been reported. There has been no information on interindividual variability of Arg194Trp and Arg399Gln polymorphisms of XRCC1 in the Iranian population. Due to the association between the polymorphisms of XRCC1 and the risk of some types of cancers, the present study was done. Methods The genetic polymorphisms of XRCC1 were detected by PCR-based method in 707 healthy individuals from Shiraz population, (Fars province, southern Iran). Results Considering that there was no statistically significant difference between males and females, the sex groups were pooled. The frequencies of 194Trp and 399Gln alleles were 9.05% and 33.95%, respectively. When both polymorphisms were considered, the linkage-disequilibrium was observed (D′ = 0.8986, r ² = 0.0413, P < 0.00001). Conclusion The present results indicated that the allelic frequencies in Iranian populations showed intermediate frequencies in comparison with European and other Asian countries.     

Population genetics and conservation of the Azorean tree Picconia azorica

Picconia azorica (Tutin) Knobl. (Oleaceae) is an endangered species, endemic to the Azores. Samples from 31 populations in 8 islands were genotyped using 8 newly developed nuclear microsatellite markers. From the amplified loci, 81% were polymorphic across all populations and the species showed a relatively high total genetic diversity (H_T = 0.7). Several populations were close to Hardy–Weinberg equilibrium while others presented positive F_IS values (0.02–0.2). The largest proportion of genetic variation (98%) occurred within populations and the level of differentiation between populations, was generally low, although 27% of the population pairwise comparisons showed relatively high differentiation values (0.25 ≤ R_ST ≤ 0.65). Relatively high levels of gene flow were also found among most populations. Using the Bayesian clustering method implemented in STRUCTURE we found a particular genetic pattern in Corvo samples, and also similarities between Santa Maria, São Miguel and Flores populations. Considerable levels of genetic admixture within P. azorica populations might have resulted from: (i) fruit dispersal by native birds; and/or (ii) human mediated dispersal between islands. Our results revealed the existence of some genetically depauperate populations needing specific conservation measures, and indicate that arbitrary translocation of individuals between islands should be avoided.     

p53 polymorphisms in Russia and Belarus: correlation of the 2-1-1 haplotype frequency with longitude

Four different polymorphisms in the human p53 gene (a 16-bp duplication in intron 3, and three RFLPs: for Bsh1236I at codon 72, for MspI in intron 6 and for BamHI in the 3 flanking region) and extended haplotypes were studied in nine geographically diverse populations from Russia and Belarus. The Yakuts differed from all other populations, as they had a significantly higher frequency of the BamHI A1 allele. Most populations did not differ significantly from each other in the frequency of the Bsh1236I polymorphism. The 16-bp duplication A1 allele and MspI A2 allele frequencies were significantly higher in the Yakut and Khant populations. Linkage disequilibrium values (D) between BamHI and other polymorphic sites were not significant in many cases; for this reason we have used the 16 bp–Bsh1236I–MspI haplotype frequencies only. Of eight possible haplotypes, five were observed in the populations investigated. Haplotype 1-2-2 was the most frequent in all populations. The next most common haplotype, 1-1-2, was present at very similar frequencies among the Byelorussians and Russians from Smolensk, but was more frequent in other populations. The frequency of haplotype 2-1-1 showed a nearly continuous decrease from West to East (from 17.857% among the Byelorussians to 0.685% in the Yakuts from the Verkhoyansk) and correlated with longitude (Spearmans r=–0.8667, P=0.0025), which may be due to natural selection and adaptation. The relationships among populations were evaluated by means of Neis D_A distances for the 16 bp–Bsh1236I–MspI haplotype frequencies. Based on the multidimensional scaling analysis a correlation between p53 haplotype frequencies and ethnicity is supposed.     

Population genetics of marine species: the interaction of natural selection and historically differentiated populations

High gene flow, particularly as mediated by larval dispersal, has usually been viewed as sufficient to limit geographic isolation as a major source of population differentiation among marine species. Despite the general observation of relatively little geographic variation among populations of high dispersal marine species many cases of divergence have been observed and natural selection has usually been invoked to explain geographic divergence. Detailed study of several allozyme polymorphisms provided additional evidence that selection may be the predominant force that determines genetic divergence in marine systems. There is, however, growing evidence that marine species with high dispersal are more subdivided than originally thought. The use of multi-locus approaches and the application of molecular techniques have provided new insight into the nature of population divergence in marine species. I argue that (1) many species, which were formerly thought to be unstructured, are in fact subdivided into genetically discrete groups, (2) it is often the case that genetically subdivided populations have distinct evolutionary histories, (3) in many cases, natural selection is the consequence of introgression between these groups, and (4) the combination of molecular assays of both nuclear and mitochondrial DNA and allozyme loci provides the best approach to understanding the evolutionary dynamics of these interacting populations.     

Distribution of blood groups, serum markers and red cell enzymes in two human populations from Northern Siberia

555 individuals were examined in relation to the ABO (with A1 and A2 subtypes), MNSs, P, Rh, Lutheran, Kell and Duffy systems. Less individuals were studied for the Kidd and Diego systems as well as for transferrins, haptoglobins and red cell enzymes, i.e. PGM1, 6-PGD, AK, and AcP. Besides, several Gm and Km (1) factors were also studied.