Genetic polymorphism of delta-aminolevulinate dehydrase in several population groups in Israel

The genetic polymorphism of red cell delta aminolevulinate dehydrase (ALADH) has been investigated in several population groups in Israel: Ashkenazi Jews, non-Ashkenazi Jews from North Africa, Egypt, Turkey, Iraq, Iran, Yemen and the Balkans, and Arabs. The distribution of the ALADH genes was not homogeneous (chi 2 = 36.83; d.f. = 8; p less than 0.0005). A significantly higher frequency of the ALADH2 gene was observed among the Ashkenazi Jews (0.2021) than among the non-Ashkenazi Jews and Arabs (gene frequencies 0.0825-0.1290) or all the other population samples so far studied (Liberia, Japan, Italy, Germany and Spain).     

Genetic heterogeneity of delta-aminolevulinate dehydrase and phosphoglycolate phosphatase in north-west Spain

The distribution of delta-aminolevulinate dehydrase and phosphoglycolate phosphatase phenotypes was analyzed in 500 autochthonous individuals from the Galician population (north-west Spain). The gene frequencies for PGP2 and ALADH2 obtained in Galicia have proved to be the lowest of all the European populations so far examined. Comparisons with other world populations were also made.     

Aminolevulinate dehydratase (E.C. 4.2.1.24): Linkage analysis

Summary Linkage data on aminolevulinate dehydratase (ALADH, E.C. 4.2.1.24) and a series of other human genetic markers are presented. One hundred and two families (25 of them being informative) from southwestern Germany were tested. Close linkage (=0.05) between ALADH and the following markers could be excluded: Rh, PGM₁, Fy, ACP1, MNSs, HLA, Bf, GLO, PGM₃, Jk, Pi, PGP, K, GPT. There is some evidence of possible linkage with HPA.     

Polymorphism of delta-aminolevulinic acid dehydratase in Basque populations

Human red cell delta-aminolevulinic acid dehydratase (ALADH; EC 4.2.1.24) polymorphism was studied in three population samples of the Basque Country. The frequency of the ALADH2 was around 0.08 and similar to that in other European countries.     

Gene frequencies of the enzymes ALADH, GOT2, GPT, PGM3, SAHH and UMPK in a Swiss population

The polymorphisms of the enzymes ALADH, GOT2, GPT, PGM3, SAHH, and UMPK have been studied in a population of Northern Switzerland (Zürich). The results are compared with those of other European populations.     

Phenotype and gene distribution of alpha-1-antitrypsin in a North Italian population.

A group of 202 unrelated Italians were screened for alpha1-antitrypsin using agarose-acrylamide electrophoresis and isoelectric focusing. The S and F gene frequencies were comparable to those found among Greeks and North European populations but they differed considerably from the frequencies found among Spaniards and Portuguese. The other gene frequencies appeared to be comparable to other populations, studied.     

Restriction fragment length polymorphisms of three collagen genes in Russians and Buryats.

The restriction fragment length polymorphisms (RFLPs) of 3 collagen genes have been studied in two USSR populations. Four high-frequency alleles, also reported in other populations, were observed. The frequencies of alleles for the polymorphic sites MspI and EcoRI of the COL1A2 gene, HindIII of the COL2A1 gene and EcoRI of the COL3A1 gene were found to be 0.836, 0.398, 0.447 and 0.786, respectively, in Russians from Moscow (Caucasians), and 0.883, 0.519, 0.648 and 0.809, respectively, in Buryats from the Baikal region (Mongoloids). The RFLPs showed a fair agreement with the Hardy-Weinberg equilibrium. The frequencies were compared with those of other populations.     

Meiotic Gene Conversion Mutants in SACCHAROMYCES CEREVISIAE . I. Isolation and Characterization of pms1-1 and pms1-2

The pms1 mutants, isolated on the basis of sharply elevated meiotic prototroph frequencies for two closely linked his4 alleles, display pleiotropic phenotypes in meiotic and mitotic cells. Two isolates carrying recessive mutations in PMS1 were characterized. They identify a function required to maintain low postmeiotic segregation (PMS) frequencies at many heterozygous sites. In addition, they are mitotic mutators. In mutant diploids, spore viability is reduced, and among survivors, gene conversion and postmeiotic segregation frequencies are increased, but reciprocal exchange frequencies are not affected. The conversion event pattern is also dramatically changed in multiply marked regions in pms1 homozygotes. The PMS1 locus maps near MET4 on chromosome XIV. The PMS1 gene may identify an excision-resynthesis long patch mismatch correction function or a function that facilitates correction tract elongation. The PMS1 gene product may also play an important role in spontaneous mitotic mutation avoidance and correction of mismatches in heteroduplex DNA formed during spontaneous and UV-induced mitotic recombination. Based on meiotic recombination models emphasizing mismatch correction in heteroduplex DNA intermediates, this interpretation is favored, but alternative interpretations involving longer recombination intermediates in the mutants are also considered.     

Distribution of hereditary blood groups among Indians in South America. 3. In Bolivia

Blood samples were procured from the following populations of putatively pure Indians in Bolivia: 503 Aymará from the Altiplano and Yungas, 30 Chama, 11 Tacana, 14 Chácobo, 109 Itonama, 67 Moré, and 27 Sirionó from the Beni and lowland rainforest. Erythrocytes from these 761 specimens were tested for antigens in the A-B-O, M-N-S-s, P, Rh-Hr, Lutheran, Kell-Cellano, Lewis, Duffy, Kidd, and Diego systems, and for the Wright agglutinogen. The serum samples were tested for haptoglobins and transferrins; and hemolysates were prepared and examined for hemoglobin types. Results of these tests are presented as phenotypes and calculated gene frequencies on appropriate tables. A map is included to show the locations of the populations from which blood samples were obtained. Frequencies are generally high for the O gene, it being the only gene of the ABO system which appears in the Chama, Chácobo and Sirionó. The presence of A₁, A₂ or B genes in the Bolivian Indians is interpreted as being most probably of caucasoid introduction. Excepting the Sirionó the frequencies are high for M and low for N genes as is usual for Amerinds, the M gene being the only one detected in the Chama. The s gene frequency in high and the S low except in the small isolated Chácobo population in which S gene frequency is extremely high for Amerinds. Inbreeding and perhaps genetic drift in this small isolate may account for this aberrancy from normal. The Bolivian specimens presented the high frequencies for genes R¹ (CDe) and R² (cDE) and the low frequencies for genes r (cde) and R⁰ (cDe) usually observed in American Indians. The Lu^a factor was observed in only one of 120 Aymará at Santa Fe in the Yungas. The Lu^a factor, when observed in Amerinds, suggests foreign introduction of the responsible gene. Fy^a gene frequencies are consistently high and excepting the Aymará and Chama so also are Jk^a frequencies. Frequencies for the Diego (Di^a) factor vary from 3.70% in 27 Sirionó to 73.33% in 30 Chama. No K, Mi^a, Vw or Wr^a antigens were demonstrable in the Indian blood samples from Bolivia. Phenotypes and calculated gene frequencies for haptoglobins and transferrins are presented. All Bolivian Indian bloods tested electrophoretically contained only hemoglobin (A) as a major component.     

Singular solutions of the diffusion equation of population genetics

The forward diffusion equation for gene frequency dynamics is solved subject to the condition that the total probability is conserved at all times. This can lead to solutions developing singular spikes (Dirac delta functions) at the gene frequencies 0 and 1. When such spikes appear in solutions they signal gene loss or gene fixation, with the "weight" associated with the spikes corresponding to the probability of loss or fixation. The forward diffusion equation is thus solved for all gene frequencies, namely the absorbing frequencies of 0 and 1 along with the continuous range of gene frequencies on the interval (0,1) that excludes the frequencies of 0 and 1. Previously, the probabilities of the absorbing frequencies of 0 and 1 were found by appeal to the backward diffusion equation, while those in the continuous range (0,1) were found from the forward diffusion equation. Our unified approach does not require two separate equations for a complete dynamical treatment of all gene frequencies within a diffusion approximation framework. For cases involving mutation, migration and selection, it is shown that a property of the deterministic part of gene frequency dynamics determines when fixation and loss can occur. It is also shown how solution of the forward equation, at long times, leads to the standard result for the fixation probability.     

Plasma cholinesterase studies on south-eastern Bantu of Mozambique.

Blood samples from four Bantu tribes in South-East Mozambique have been phenotyped for the plasma cholinesterase variants of the E1 locus. A control roup of 153 Portuguese residents in Mozambique have also been phenotyped. The frequencies of both the E1a and E1f genes in the Portuguese population is very similar to those in other Caucasian populations. The absence of the E1a gene in the four Bantu tribes provides more evidence of the rarity of this gene in Negroid populations. There is an increased frequency of E1f gene in all tribes as compared with previous surveys. The Ronga and Bitonga tribes have similar E1f frequencies of 0.047 and 0.048, respectively. The Shangana has an E1f frequency of 0.060, and the corresponding figure for the Chopi tribe is 0.089. The latter is the highest recorded frequency for this gene. The results give some support to the doubts concerning the affiliation of the Chopi tribe.     

Chloroplast Genetics of Chlamydomonas. II. Mapping by Cosegregation Frequency Analysis

This paper presents segregation and cosegregation data for a set of 15 chloroplast genes of Chlamydomonas, and uses these data to generate a linear map of the chloroplast genome. The data were derived from pedigree analysis of a total of 1596 zoospore clones resulting from 12 crosses in each of which 4 to 7 pairs of chloroplast alleles were segregating. The crosses are a subset of those previously described (Sager and Ramanis 1976). By means of pedigree analysis, Type II segregations (nonreciprocal conversion-like events) were distinguished from Type III segregations (reciprocal events). The average frequency of Type II segregation was found to be the same for all 15 genes, indicating randomness of this event with respect to map location (Figure 1). Type III segregations occurred with a different and characteristic frequency for each gene, and were interpreted as a measure of the distance of each gene from the postulated centromere-like attachment point.Cosegregations, involving two or more genes, occurred with frequencies characteristic of the particular genes and much lower than expected for the product of single-gene events, indicating strong positive interference. Pairwise cosegregation frequencies provided unambiguous data for the gene order, confirmed by cosegregation runs of three or more genes. Apparent lengths of cosegregation runs, as fractions of the total map, indicate much longer stretches of gene conversion-like events than have been reported for other genetic systems. Comparisons of cosegregation frequencies in cross 20 after 15', 30' and 15' UV irradiation of the mt(+) before mating, indicate little if any consistent effect of this irradiation on segregation events.     

Distribution of haptoglobin subtypes in French Basques.

THE Hl1f, Hp1s and Hp2 gene frequencies were studied in two French population samples: one from the Toulouse area and one from a Basque district. The hp alpha1F and alpha1S polypeptide chains were determined by a simple technique. The observations were in accordance with previous findings in Caucasoid populations. The frequency of the Hp1S gene was slightly higher in the Basque sample than in the group from Toulouse.     

Esterase-D polymorphism in Assam by cellulose acetate electrophoresis.

With the help of a simplified and quick method, cellulose acetate electrophoresis, the phenotypes of esterase D were determined in an Assamese population. The gene frequencies of Es D(1) were 0.7263 and 0.2737 for Es D(2).     

Medical genetic study of the population of Turkmenia. VI. Intrapopulation variability from an analysis of marriage migrations and ABO and Hp marker systems

By the sampling procedure, the distribution of phenotypic and genotypic frequencies of ABO and Hp systems and the structure of intermarriage migration in Turkmen population was studied. The geographical subdivision of the Turkmen population coincided with its ethnic divergency. The main Turkmen tribes are highly isolated (the gametic index is 0.965 to 1.0) and the differences in gene frequencies between tribes are significant. The mean gene frequencies for the ABO system in the Turkmen population are: I0-0.5373, IA-0.2601, IB-0.2025, these being Hp1-0.284, Hp2-0.716 for the Hp system.     

Population Genetics of Drosophila Amylase. II. Geographic Patterns in D. PSEUDOOBSCURA

Morph frequencies of three related polymorphisms were determined in ten natural populations of Drosophila pseudoobscura. They are the well-known inversion polymorphism of the third chromosome and the polymorphism for alpha-amylase produced by the structural gene Amy (which resides on the third chromosome). The third polymorphism was for tissue-specific expression of Amy in adult midguts; a total of 13 different patterns of activity have been observed. The preceding paper (Powell and Lichtenfels 1979) reports evidence that the variation in Amy expression is under polygenic control. Here we show that the polymorphism for midgut patterns occurs in natural populations and is not an artifact of laboratory rearing.--From population to population, Amy allele frequencies and frequencies of inversions belonging to different phylads vary coordinately. The geographic variation in alpha-amylase midgut activity patterns is uncorrelated with that for the other two types of polymorphisms. Furthermore, no correlation was detected between activity pattern(s) and Amy genotype(s) when both were assayed in the same individual.--These results imply that whatever the evolutionary-ecological forces are that control frequencies of the structural gene variants, they are not the same factors that control the frequencies of polymorphic genetic factors responsible for the tissue-specific expression of the enzyme.     

Population Genetics of Euphydryas Butterflies. I. Genetic Variation and the Neutrality Hypothesis

Twenty-one populations of the checkerspot butterfly, Euphydryas editha, and ten populations of Euphydryas chalcedona were sampled for genetic variation at eight polymorphic enzyme loci. Both species possessed loci that were highly variable from population to population and loci that were virtually identical across all populations sampled. Our data indicate that the neutrality hypothesis is untenable for the loci studied, and therefore selection is indicated as the major factor responsible for producing these patterns. Thorough ecological work allowed gene flow to be ruled out (in almost all instances) as a factor maintaining similar gene frequencies across populations. The Lewontin-Krakauer test indicated magnitudes of heterogeneity among standardized variances of gene frequencies inconsistent with the neutrality hypothesis. The question of whether or not to correct this statistic for sample size is discussed. Observed equitability of gene frequencies of multiple allelic loci was found to be greater than that predicted under the neutrality hypothesis. Genetic differentiation persisting through two generations was found between the one pair of populations known to exchange significant numbers of individuals per generation. Two matrices of genetic distance between populations, based on the eight loci sampled, were found to be significantly correlated with a matrix of environmental distance, based on measures of fourteen environmental parameters. Correlations between gene frequencies and environmental parameters, results of multiple regression analysis, and results of principle component analysis showed strong patterns of association and of "explained" variation. The correlation analyses suggest which factors might be further investigated as proximate selective agents.     

Serum protein groups (Hp, GC, C3) in patients with gastric carcinoma.

The phenotypes and gene frequencies of 3 serum protein systems (Hp, GC and C3) were studied in 114 consecutive patients from all over Greece with gastric carcinoma. Healthy Greeks studied previously in our Department served as controls. No significant differences were found between patients and controls concerning Hp. Significant differences were found in the GC and C3 systems; GC 2-1 and C3F phenotype as well as C3*F gene frequencies were significantly higher in patients than in controls.