Some blood genetic characteristics of several Sudanese tribes

The distribution of ABO and Rhesus blood groups, serum haptoglobin, and transferrin; red cell glucose-6-phosphate dehydrogenase and acid phosphatase; and hemoglobin was studied among the two aboriginal negroid tribes (Nuba and Fur); the Nilotic tribe; five tribes of Arab ancestory; and a mixed group of other minor tribes of Arab origin. The Nilotic and Nuba tribes were genetically quite distinct from the rest, with lower R1, R2, and r in the Rhesus system and low HbS and Gd-. The Arab tribes had a genetic structure which was intermediate between that of the original negroid population of the Sudan and the Arabs to the north. However, some of the Arab tribes had special genetical characteristics, e.g., Messeria had high TfD1; both Messeria and Hawazma had high HbS and Gd-, while GdA was higher only in the Hawazma. The Gaalin had very low HbS, Ro, GdA, and Gd-, suggestive of less negroid admixture compared to Messeria and Hawazma. The Fur, though an aboriginal negroid tribe, had genetic characteristics similar to Arabs.     

The denied land rights of the indigenous peoples and their endangered livelihood and survival: the case of the Nuba of the Sudan

The current situation of indigenous peoples in the Sudan is the result of the independent state's adoption of land and other policies identical to those introduced by colonialists more than a century ago. The Sudanese state has not only unwittingly maintained some colonial coercive institutions and policies but it has introduced more aggressive ones and brutally deployed them against its indigenous peoples, particularly the Nuba. In the light of this, this paper attempts to demonstrate analytically how some historical and contemporary socio-political dynamics have continued systematically to deprive these indigenous Nuba peoples of their customary land, and to assess to what extent the recently concluded Comprehensive Peace Agreement (CPA) has been successful in addressing the land question as one of the root causes of the recurring civil wars in the Sudan in general and in the Nuba Mountains in particular.     

Some blood genetic markers of selected tribes in Western Saudi Arabia

A total of 292 randomly selected subjects belonging to two indigenous Arab tribes (Harbi and Ghamid) and two immigrant tribes (Mograbi and Mowallad), residents in Western Saudi Arabia, have been tested for genetic variants of six blood groups, four serum proteins, and five red cell enzyme systems. The distribution of the polymorphic systems was different between indigenous and immigrant tribes, and the present Arab population shows a considerable degree of admixture from the surrounding countries, in particular Africa.     

Genetic heterogeneity among the Negroid and Arab tribes of the Sudan

Genetic distance analysis was carried out among seven tribes of the Sudan comprising three Negroid (Nuba, Fur, and Nilotes) and four Arab tribes (Beja, Gaalin, Hawazma, and Messeria) on the basis of six polymorphic loci (ABO and Rhesus blood groups; haemoglobin and red cell glucose-6-phosphate dehydrogenase; serum haptoglobin and transferrin polymorphisms) controlling 21 alleles and compared with the Arab and Negroid populations in neighbouring countries. The Nuba and Nilotes have been found to have Negroid genetic characteristics, while the Fur are intermediate between the Arabs and Negroids. The Beja and Gaalin tribes have more pronounced Arab genetic characteristics than the Hawazma and Messeria, who have a great deal of Negroid admixture.     

Balancing selection response and rate of inbreeding by including genetic relationships in selection decisions

An iterative selection strategy, based on estimated breeding values (EBV) and average relationship among selected individuals, is proposed to optimise the balance between genetic response and inbreeding. Stochastic simulation was used to compare rates of inbreeding and genetic gain with those of other strategies. For a range of heritabilities, population sizes and mating ratios, the iterative strategy, denoted ADJEBV, outperforms other strategies, giving the greatest genetic gain at a given rate of inbreeding and the least breeding at a given genetic gain. Where selection is currently by truncation on the EBV, with a restriction on the number of full-sibs selected, it should be possible to maintain similar levels of genetic gain and inbreeding with a reduction in population size of 10–30%, by changing to the iterative strategy. If performance is measured by the reduction in cumulative inbreeding without losing more than a given amount of genetic gain relative to results obtained under truncation selection on the EBV, then with the EBV based on a family index, the performance of ADJEBV is greater at low heritability, and is generally greater than where EBV are based on individual records. When comparisons of genetic response and inbreeding are made for alternative breeding scheme designs, schemes which give higher genetic gain within acceptable inbreeding levels would usually be favoured. If comparisons are made on this basis, then the selection method used should be ADJEBV, which maximises the genetic gain for a given level of inbreeding. The results indicated that all selection strategies used to reduce inbreeding had very small effects on the variance of gain, and so differences in this respect are unlikely to affect choices among selection strategies. Selection criteria are recommended based on maximising a selection objective which specifies the desired balance between genetic gain and inbreeding.     

Microsatellite diversity among the primitive tribes of India

The present study was undertaken to determine the extent of diversity at 12 microsatellite short tandem repeat (STR) loci in seven primitive tribal populations of India with diverse linguistic and geographic backgrounds. DNA samples of 160 unrelated individuals were analyzed for 12 STR loci by multiplex polymerase chain reaction (PCR). Gene diversity analysis suggested that the average heterozygosity was uniformly high ( >0.7) in these groups and varied from 0.705 to 0.794. The Hardy-Weinberg equilibrium analysis revealed that these populations were in genetic equilibrium at almost all the loci. The overall G(ST) value was high (G(ST) = 0.051; range between 0.026 and 0.098 among the loci), reflecting the degree of differentiation/heterogeneity of seven populations studied for these loci. The cluster analysis and multidimensional scaling of genetic distances reveal two broad clusters of populations, besides Moolu Kurumba maintaining their distinct genetic identity vis-à-vis other populations. The genetic affinity for the three tribes of the Indo-European family could be explained based on geography and Language but not for the four Dravidian tribes as reflected by the NJT and MDS plots. For the overall data, the insignificant MANTEL correlations between genetic, linguistic and geographic distances suggest that the genetic variation among these tribes is not patterned along geographic and/or linguistic lines.     

A study of some genetic characteristics of the Fur and Baggara tribes of the Sudan

The average inbreeding coefficients of the highly consanguineous Fur and Baggara tribes of Western Sudan were 0.04167 and 0.04450, respectively. Two hundred ninety-eight subjects from the two tribes were tested for polymorphism of hemoglobins, seven red cell enzymes, and four serum proteins. The Baggara showed a higher gene frequency of HbS and TfD and lower gene frequency of GdA and PC compared to the Fur. Both tribes showed a low gene frequency of PGM1 and high frequency of G6PD deficiency when compared to other Sudanese tribes. In spite of the high degree of inbreeding, no significant deviation from the Hardy-Weinburg equilibrium was observed in either tribe. The effects of inbreeding seem to be offset by mixing between the two tribes on Gabal Marra Plateau. The flow of the sickle gene from the Baggara into the Fur and other Sudanese tribes is discussed.     

Some blood genetic markers in the Korkus of Central India

A sample of 102 individuals from the Korkus tribe, an Australoid race inhabiting Central India, was studied for the distribution of haemoglobin and ten red cell enzyme types. Polymorphism was observed in G6P dehydrogenase, acid phosphatase, adenylate kinase and glyoxalase I types and in phosphoglucomutase subtypes. The lactate and malate dehydrogenases, glucose phosphate isomerase and superoxide dismutase systems were monomorphic. A single case of HbAS was observed. The Korkus were found to have GdA+; lower frequencies of pa, AK2, GLO1 and PGM2+ were observed in the Korkus in comparison to other related tribes and caste Hindus of the same region.     

近交对单倍体-二倍体种群平衡遗传多态性的影响

本文通过对一个双等位基因位点在产雄孤雌生殖遗传体系下不完全同胞交配的模拟 ,研究了在显性、共显性和超显性遗传模式下近交对平衡多态性的影响。结果显示 :相对于二倍体 -二倍体种群 ,不完全同胞交配会减少产雄孤雌生殖种群的遗传变异。然而 ,在各种情况下 ,近交对单倍体 -二倍体种群的总体影响不如对二倍体 -二倍体种群极端     

Ethnic communities in Israel: The genetic blood markers of the Moroccan Jews

One hundred and ninety-six Moroccan Jews now settled in Israel were typed for 7 blood groups, 12 red cell enzymes and 2 plasma protein systems. Their blood group picture is in agreement with results previously obtained on different samples of Moroccan Jews: rather high B in ABO, somewhat elevated frequencies of cDE and cDe in Rh and K in Kell. Differences in various blood markers exist between them and other North African Jewish communities. This fact, together with data on disease distribution and HLA frequencies, supports our assumption that Jews in the North African diaspora lived as small secluded isolates even within the same geographical zones. Comparisons with meager data on the neighboring non-Jewish populations do not disclose any resemblance to either Arab or Berber inhabitants of Morocco.     

Effect of mass selection on the within-family genetic variance in finite populations

Summary The adequacy of an expression for the withinfamily genetic variance under pure random drift in an additive infinitesimal model was tested via simulation in populations undergoing mass selection. Two hundred or one thousand unlinked loci with two alleles at initial frequencies of 1/2 were considered. The size of the population was 100 (50 males and 50 females). Full-sib matings were carried out for 15 generations with only one male and one female chosen as parents each generation, either randomly or on an individual phenotypic value. In the unselected population, results obtained from 200 replicates were in agreement with predictions. With mass selection, within-family genetic variance was overpredicted by theory from the 12th and 4th generations for the 1,000 and 200 loci cases, respectively. Taking into account the observed change in gene frequencies in the algorithm led to a much better agreement with observed values. Results for the distribution of gene frequencies and the withinlocus genetic covariance are presented. It is concluded that the expression for the within-family genetic variance derived for pure random drift holds well for mass selection within the limits of an additive infinitesimal model.     

Study of possible genetic predisposition to endemic goitre among the Fur and Baggara tribes of the Sudan

The overall prevalence rate of endemic goitre among the Fur and Baggara tribes of Western Sudan was found to be 74%. Family studies in 60 nuclear families showed a significantly higher incidence of endemic goitre among the offspring of affected parents than among the offspring of normal parents. This suggests a possible genetic predisposition to endemic goitre. The proportion of phenylthiocarbamide (PTC) non-tasters was found to be 13% among the goitrous subjects compared to 17.5% among the non-goitrous subjects. However, the association with PTC as well as with 6 blood-genetic markers, was not statistically significant.     

Assessment of the genetic diversity and genetic relationships of Lilium in China using ISSR markers

China is a center of natural distribution and diversity of genus Lilium around the world. In the study, the genetic diversity and genetic relationships of Lilium in China were analyzed by inter-simple sequence Repeat (ISSR) markers. The 6 highly polymorphic ISSR primers were selected to amplify the 20 Lilium species. The results showed that a total of 114 DNA bands were amplified, all of which were polymorphic loci (P = 100%), the effective number of alleles (Ne) was 1.2753, and the difference value between observed number of alleles (Na) and effective number of alleles (Ne) was 0.7247, and the Nei's genetic diversity (H) was 0.2048, and the Shannon's information index (I) was 0.3503. These results indicated that there is significant genetic difference among Lilium species in China. Taking the average genetic similarity coefficient (Gs) 0.5313 as the threshold, the 20 tested Lilium species were clustered into 5 groups, which was not entirely consistent with traditional clustering by morphological traits. The results obtained from this study can provide a reference for the molecular study of Lilium germplasm resources.     

Ethnic communities in Israel: The genetic blood markers of the Babylonian Jews

One hundred eighty-eight Jewish individuals who either they or whose both parents were born in Iraq were typed for 7 blood groups (ABO, MNS, Rh, Kell, Duffy, P and Kidd), 12 red cell enzyme systems and 2 serum proteins. Iraqi Jews are characterized by a high frequency of A (in ABO), N (in MNS), low cde (Rh) and low Hp-1. Several rare electrophoretic variants were encountered: PGM₁ 6-1, PHI 3-1 and PHI 2-1, and an unidentified AK phenotype. No evidence of Negroid admixture was found in their gene pool. Comparisons with results previously obtained in Iraqi Jews show general similarities in frequencies while comparisons with neighboring non-Jewish populations suggest divergence in most systems investigated. The difficulties of assessing relationships on the basis of a few selected differences and the need for careful interpretations of similarities are emphasized.     

Mate choice evolution, dominance effects, and the maintenance of genetic variation

Female mate choice influences the maintenance of genetic variation by altering the mating success of males with different genotypes. The evolution of preferences themselves, on the other hand, depends on genetic variation present in the population. Few models have tracked this feedback between a choice gene and its effects on genetic variation, in particular when genes that determine offspring viability and attractiveness have dominance effects. Here we build a population genetic model that allows comparing the evolution of various choice rules in a single framework. We first consider preferences for good genes and show that focused preferences for homozygotes evolve more easily than broad preferences, which allow heterozygous males high mating success too. This occurs despite better maintenance of genetic diversity in the latter scenario, and we discuss why empirical findings of superior mating success of heterozygous males consequently do not immediately lead to a better understanding of the lek paradox. Our results thus suggest that the mechanisms that help maintain genetic diversity also have a flipside of making female choice an inaccurate means of producing the desired kind of offspring. We then consider preferences for heterozygosity per se, and show that these evolve only under very special conditions. Choice for compatible genotypes can evolve but its selective advantage diminishes quickly due to frequency-dependent selection. Finally, we show that our model reproduces earlier results on selfing, when the female choice strategy produces assortative mating. Overall, our model indicates that various forms of heterozygote-favouring (or variable) female choice pose a problem for the theory of sexual ornamentation based on indirect benefits, rather than a solution.     

Electrophoretic variants in three Amerindian tribes: the Baniwa, Kanamari, and Central Pano of western Brazil.

Data are presented on electrophoretic variants of 25 polypeptides found in the blood serum and erythrocytes, in 812 individuals from three Amerindian tribes, the Pano, the Baniwa, and the Kanamari. Two "private polymorphisms" were encountered, of PEPB in the Pano and CAII in the Baniwa. A single example of a different PEPB variant was encountered in the Baniwa, and two possible examples of an unstable variant of HGB A2 in the Kanamari. In addition, the well-known A variant of ACP1, the Duarte variant of GALT, the 2 variant of Hp and the 2 variant of PGM1 occurred in polymorphic proportions in all three tribes, and the TFDChi variant was present as a polymorphism in the Baniwa. These data have recently been incorporated into a treatment which concludes that the eight electrophoretically-defined "private polymorphisms" thus far encountered in Amerindian tribes can be explained by a mutation pressure of 0.7 x 10(-5)/locus/generation on the assumption of neutrality of the phenotypes in question (Neel and Thompson, '78).     

RAPD markers for constructing intraspecific tomato genetic maps

The existing molecular genetic maps of the tomato, Lycopersicon spp, are constructed based on isozyme and RFLP polymorphisms between tomato species. These maps are useful for certain applications but have few markers that exhibit sufficient polymorphisms for intraspecific analysis and manipulations within the cultivated tomato. The purpose of this study was to investigate the relative potential of RAPD technology, as compared to isozymes and RFLPs, to generate polymorphic DNA markers within cultivated tomatoes. Sixteen isozymes and 25 RFLP clones that were known to detect polymorphism between L. esculentum and L. pennellii, and 313 random oligonucleotide primers were examined. None of the isozymes and only four of the RFLP clones (i.e., 16%) revealed polymorphism between the cultivated varieties whereas up to 63% of the RAPD primers detected one or more polymorphic DNA fragments between these varieties. All RAPD primers detected polymorphism between L. esculentum and L. pennellii genotypes. These results clearly indicate that RAPD technology can generate sufficient genetic markers exploiting sequence differences within cultivated tomatoes to facilitate construction of intraspecific genetic maps.Abbreviations RFLP restriction fragments length polymorphism - RAPD random amplified polymorphic DNA - PCR polymerase chain reaction - QTLs quantitative trait loci     

DNA fingerprinting: a tool for determining genetic distances between strains of poultry

Summary DNA fingerprinting, a technique based on the detection of hypervariable minisatellite regions in DNA restriction fragments, was tested for its applicability to conduct population genetics in poultry. Using MspI digestion and phage M13 DNA as a probe, between 25 and 35 minisatellite-containing DNA fragments were observed per bird. Comparison of the banding pattern of offspring with their parents revealed that the bands were inherited as stable genetic traits. The variability of the DNA fingerprinting pattern was reduced in inbred strains. DNA fingerprints of chickens from five well-defined populations of known genetic relationships were analyzed and indices of genetic distances were computed. They correctly reflected the history of these strains, indicating that DNA fingerprinting may be a powerful tool to characterize genetic relationships between different breeding populations of the same species.     

Comparative analysis of genetic diversity and population genetic structure in Abies chensiensis and Abies fargesii inferred from microsatellite markers

Abies chensiensis Tieghem and Abies fargesii Franchet are two closely related tree species of Pinaceae endemic to China. A. chensiensis is usually found scattered in small forest fragments, whereas A. fargesii is a dominant member of coniferous forest. To evaluate the genetic effect of fragmentation on A. chensiensis, a total of 24 populations were sampled from the whole distribution of the two species. Seven nuclear microsatellite loci were employed to analyze comparatively the genetic diversity and population genetic differentiation. Both A. chensiensis and A. fargesii have high level within-population genetic diversity and low inter-population genetic differentiation. Low microsatellite differentiation (2.1%) between A. fargesii and A. chensiensis was observed. But microsatellite marker was able to discriminate most populations of these two species. Compared to A. fargesii, A. chensiensi has lower allelic diversity and higher genetic differentiation among populations. It suggested the existence of negative genetic impacts of habitat fragmentation on A. chensiensis.     

The St. Lawrence Island Eskimos: genetic variation and genetic distance

The Eskimos of St. Lawrence Island have been typed for genetic variation at 44 discrete genetic loci. Three private polymorphisms, at the 2,3-diphosphoglycerate mutase, peptidase B, and purine nucleoside phosphorylase loci, have been observed, which may be useful in future studies of genetic relationships between Eskimos and other circumpolar populations. Genetic distance analysis reveals a close relationship between the St. Lawrence Island Eskimos and other Eskimo populations and that the Eskimo populations form a distinct cluster from Amerindian populations. The St. Lawrence Island Eskimos appear to be more similar to Asiatic Eskimos than to other groups. Caucasian admixture in this population is estimated to be between 2 and 7%.