Group-specific component (Gc) and transferrin (Tf) subtypes ascertained by isoelectric focusing

Simultaneous subtyping of Gc and TfC by isoelectric focusing allows us to compute the following gene frequencies for the Belgian population: Gc1S = 0.543 Gc1F = 0.167 Gc2 = 0.290 TfC1 = 0.784 TfC2 = 0.206 TfB = 0.007 TfD = 0.003. The Gc bands were precipitated by sulfosalicylic acid instead of by immunofixation.     

Gc subtypes in Finns, Swedes and Swedish Lapps

The group-specific component (Gc) subtypes were determined by isoelectric focusing and immunoblotting. The gene frequencies in the Swedish Lapps were Gc1F = 0.412, Gc1S = 0.367 and Gc2 = 0.221, which was significantly different from the frequencies found in Finns and in the populations of northern and central Sweden (p less than 0.001). The gene frequencies in the Swedish Lapps, although similar to those in Asiatic populations, are probably not reflecting an Asiatic influence, since the accumulated genetic information on the Swedish Lapps suggests that founder effect and genetic drift are to a large extent responsible for the peculiar gene pool of the original Lapp population.     

Gc and C3 polymorphisms in Central Sardinia

The distribution of phenotypes and gene frequencies of the group-specific component (Gc) and C3 complement were studied in Central Sardinian sample. The gene frequencies were:Gc1 = 0.733; C3F = 0.237.     

Gc and C3 polymorphisms in South Sardinia

The distribution of phenotypes and gene frequencies of the group-specific component (Gc) and C3 complement were studied in South Sardinia. The gene frequencies were: Gc1 = 0.7346; C3F = 0.1963.     

Group-specific component (Gc): subtypes in the Finnish population. Description of a new allele and an apparent mother-child incompatibility

The group-specific component (Gc) subtypes were determined in 575 adult Finns by immunoblotting after isoelectric focusing in agarose gel. The gene frequencies were Gc1S = 0.661, Gc1F = 0.139 and Gc2 = 0.200. This material included one rare allele, a more acidically focusing Gc 2 (named Gc 2A18). The phenotypes of 200 mother-child pairs studied were in accordance with the three-allelic mode of inheritance. An apparent mother-child incompatibility observed during routine paternity testing is reported.     

Genetic polymorphism of group-specific component/vitamin-D-binding protein subtypes in six populations from north-eastern China

On six populations from North-Eastern China the frequencies of Gc subtypes were studied by isoelectric focusing on ultra-thin polyacrylamidegel followed by the improved sulfosalicylic acid precipitation. The following Gc subtype allele frequencies could be observed in the Han (Harbin), Ewenki, Tahur, Mongolian, Oroquen and Xibe populations: Gc*1F = 0.4246, 0.4941, 0.4479, 0.4077, 0.4606 and 0.4503; Gc*1S = 0.2587, 0.2936, 0.3151, 0.2822, 0.3370 and 0.3035; Gc*2 = 0.3065, 0.2064, 0.2266, 0.3006, 0.2022 and 0.2388. In addition to this 16 individuals of five populations showed rare Gc variant alleles (1A3, 1A8, 1A9, 1A14, 1C?).     

Distribution of group-specific component/vitamin-D-binding protein subtypes in Saudi Arabia

The distribution of group-specific component (Gc) phenotypes and the Gc allele frequencies were investigated in 1,082 individuals from five different provinces of Saudi Arabia by the combined use of isoelectric focusing and immunofixation. Between provinces variations in the Gc allele frequencies were found. Gc1S decreased and Gc1F increased from the northwest to the southeast in Saudi Arabia. The overall frequencies in Saudi Arabia were 0.236 for Gc1F, 0.610 for Gc1S, 0.150 for Gc2 and 0.004 for rare alleles. The observed frequencies did not differ significantly from those found in other population samples from the Middle East. In nine samples rare Gc variants were found.     

Protein subtype polymorphisms (Gc and Tf) in a Catalan population from Gerona (northeastern Spain)

The Tf and Gc polymorphic subtype variants have been examined by means of isoelectric focusing in a population sample from two subpyrenean regions in the province of Gerona (Northeast Spain). The estimated allele frequencies were Tf*C1 = 0.774, Tf*C2 = 0.167, TF*C3 = 0.055, TF*B = 0.004; Gc*1F = 0.129, Gc*1S = 0.555 and Gc*2 = 0.316. These values are in general similar to those so far reported in other Spanish populations. The comparisons between our data and those published in Spain, indicate that the present sample is closer to Barcelona than to the other groups compared.     

PGM1 and Gc subtype gene frequencies in a California Hispanic population.

The gene frequencies of the subtypes of the Gc (group-specific component) protein and PGM1 (phosphoglucomutase) enzyme systems have been determined by means of isoelectric focusing for a California Hispanic population (no. = 404). The Gc subtyping, done by immunofixation on a polyacrylamide gel, gave the following results: 1s = 0.491; 1f = 0.288; 2 = 0.218; variant = 0.0025. The PGM subtyping, done on agarose gel, gave results as follows: 1+ = 0.502; 1- = 0.266; 2+ = 0.128; 2- = 0.104. Because the gene frequencies for Hispanics in both these systems are relatively evenly balanced, the systems are of great value in Hispanic paternity investigations. The average power of exclusion is calculated to be 34.4% (Gc subtyping) and 39.8% (PGM1 subtyping).     

Subtypes of serum group specific component (Gc) in normal conditions and in pathology

In the framework of the ecogenetic research programme, the data are presented on the genetic polymorphism of the vitamin D-binding protein (Gc) in various USSR populations. Blood serum samples were studied, taken from the Russians of the town Yegorievsk, Moscow Region (p = 321) and 113 Russian patients with tuberculosis using the method of isoelectrofocusing. The information was obtained of the Gc frequencies in two population units of Buryats of Aginsky and Ost-Ordynsky Autonomous Districts of Chita and Irkutsk Regions, including the Olkhon island (on the lake Baikal), in totality, 593 individuals and 13 local groups. The position of the studied Russian and Buryat groups within the gene frequency co-ordinate space is well in line with the estimated area of their localization, with regard to the world distribution. Among the Buryat populations studied, there is distinct heterogeneity for which the factor Gc1F plays a leading role within the Gc system/responsible for 92% of all possible genetic variability. Gc factor frequencies in Buryats range within the following limits: 1F.-0.3864-0.6023, 1S-0.1895-0.4535, 2-0.1364-0.2581. For the Russians of Yegorievsk and the patients with tuberculosis of Moscow and Moscow Region following allele frequencies are established: 1-F0.1169, 1S-0.5476, 2-0.1364 and 1F-0.1106, 1S-0.5531, 2-0.3363, respectively, which indicates that no association exists between Gc variants and tuberculosis. The correlation of the Gc allele frequency distribution with the ratio of insulin-independent diabetes (type 2) world-wide indicates that expression of high frequency of diseases is accompanied with comparatively rare characteristic combination of frequencies of three Gc alleles.     

Group-specific component, alpha1-antitrypsin and esterase D in Canadian Eskimos.

Three genetic markers - group-specific component (Gc), alpha1-antitrypsin, and esterase D - were examined in a population of Eskimos from Igloolik in the eastern Canadian Arctic. Gc and esterase D were found to be polymorphic. In addition to the common Gc types, an anodal variant called Gc Igloolik was found, probably identical to previously reported Gc Eskimo. Gene frequencies were Gc1: 0.6524, Gc2: 0.3373, GcIgl: 0.0104, for 338 Eskimos. Genetic types of alpha1-antitrypsin (Pi types) were mostly M, with two MS sibs who were half Caucasian, in 170 Eskimos. Frequencies of the esterase D allele in 336 Eskimos were EsD1: 0.7083, EsD2: 0.2917. The frequencies of Gc2 and EsD2 are both higher than are found in Caucasian populations.     

Group-specific component (Gc) 'subtypes' of Gc1 by isoelectric focusing in US blacks and whites.

Isoelectric focusing was applied to the Gc polymorphism. In agreement with Constans et al., we found two common 'subtypes' of Gc1 that could not be identified by conventional electrophoretic procedures. They are labeled Gc1F and Gc1S. Gc1F has a slightly lower isoelectric point than Gc1S. In groups of US blacks the allele frequencies were for Gc1F; 0.732 and for Gc1S; 0.147. In whites these figures were 0.149 and 0.572. We also found GcAb in blacks with a frequency of 0.015. The concentrations in serum of Gc protein as measured by radial immunodiffusion did not differ according to phenotype.     

白、苗、土家、彝族组特异性成分亚型的研究

用薄层聚丙烯酰胺凝胶等电聚焦结合免疫固定的方法分析了中国四个少数民族的组特异性成分(Gc)的亚型分布。白族、苗族、土家族、彝族Gc~1F的基因频率分别为0.4082,0.4229,0.3592,0.4248;Gc~1S的基因频率分别为0.3035,0.2687,0.2864,0.3301,Gc~2的基因频率分别为 0.2577,0.3035,0.3342,0.2208。另外,在四个民族中发现十六个个体带有Gc的罕见变异型等位基因。     

On the variability of Gc subtypes in Italy

909 individuals from different places of Italy were analyzed for the distribution of Gc subtypes. The observed heterogeneity in the distribution of the allele frequencies was found to be statistically significant. Comparing our results with those reported by other authors it is seen that within Italy a considerable regional variation in the frequencies of the Gc subtype alleles is present. However, there are no indications for any particular distribution patterns or gradients. In one of our samples (Bari district), one case of Gc 1S-1C3 was found.     

Distribution of transferrin and group-specific component subtypes among Parsis of India

Transferrin and group-specific component subtypes were studied by isoelectric focusing of sera from 253 Parsis in India. The frequencies of TfC1, TfC2, TfC3 and TfC4 were found to be 0.8083, 0.1719, 0.019 and 0.0020, respectively. TfB was present in a frequency of 0.0059. The frequencies of Gc alleles were found to be 0.4478 for GcIF, 0.3875 for GcIS and 0.1647 for Gc2. The gene frequency of GcIF was rather high in comparison with Iranian and Indian populations.     

Population genetics of the group specific component (Gc) and phosphoglucomutase (PGM1) studied by isoelectric focusing

For the determination of the group-specific component (Gc) and phosphoglucomutase (PGM1) phenotypes, isoelectric focusing was performed on two samples, one of Jat Sikh of northwest India, the other of northeast English. The subtype frequencies of these two systems do not differentiate the two populations sampled. Synthesis of the existing data shows distinct PGM1 and Gc subtype frequencies in various ethnic and racial groups. The anthropological implication of these subtype frequencies is discussed.     

Gametocidal genes in wheat and its relatives. IV. Functional relationships between six gametocidal genes.

Gametocidal (Gc) genes in Aegilops species are known to cause gamete abortion and chromosome breakage when they are introduced into the wheat genetic background. Interactions of five Gc genes so far identified were investigated by analysis of wheat hybrids among lines carrying different gametocidal genes. As a result, the genes were classified into three functional groups. The first group includes two Gc genes of Ae. speltoides (Gc1a and Gc1b) and one gene (Gc-Sl3) on chromosome 2S1 of Ae. sharonensis. These genes were hypostatic to the genes (Gc-Sl1, Gc-Sl2) on chromosome 4S1 of Ae. longissima and Ae. sharonensis, which constitute the second group. In addition, plants carrying Gc genes of both the first and the second group produced progeny with higher frequencies of chromosome breakage than those found in the progeny of single gene carriers. It was concluded that there were specific interactions between these genes to enhance chromosome breakage. On the other hand, there was no interaction between the Gc gene (Gc-C) of Ae. triuncialis, the third group, and Gc genes belonging to the former two groups. These functional groups might be a reflection of the mechanisms by which Gc genes induce gamete abortion and chromosome breakage. Based on functional and local relationships, the symbols of the Gc genes were systematically redesignated.     

A genetic study among the Lepchas of the Darjeeling area of eastern India

A total of 215 Lepchas (75 Buddhists and 140 Christians) living in the Kalimpong subdivision, Darjeeling district, West Bengal, India, were investigated for the distribution of haemoglobin, serum proteins and red cell enzymes. The gene frequencies were as follows: HbE = 0.02; Hp1 = 0.18; TfB = 0.007; TfDChi = 0.005; Gc2 = 0.22; pa = 0.18; pc = 0.03; PGM2(1) = 0.18; PGM6(1) = 0.002; PGDc = 0.17; AK2 = 0.02; GLO1 = 0.21. The most striking features were the complete lack of G6PD deficiency and very high frequency of PGDC. The remaining loci (serum albumin, lactate dehydrogenase, malate dehydrogenase and glucose-6-phosphate dehydrogenase, phosphohexose isomerase and superoxide dismutase) were monomorphic. The gene frequencies were similar in the Buddhist and Christian Lepchas. The observed average heterozygosity (9 loci) was 0.20 in the entire sample.     

The distribution of the group specific component (Gc) in four endogamous groups of Punjab, North India

The paper reports the distribution of group specific component (Gc) types among four endogamous groups of Punjab: Jat Sikh, Khatri, Ramgarhia, and Ramdasia. A total of 418 individuals were tested for this polymorphism. The frequency of Gc1 alleles ranges between 0.7056 and 0.7636. These frequencies are compared with those obtained in other Indian populations.