The frequencies of the serum amyloid A2 alleles in healthy (Turkish, Azerbaijan and Kazakh) populations

The Amyloid A1 (AA1) and A2 (AA2) proteins, which result from proteolytic cleavage of the Serum Amyloid A1 (SAA1) and A2 (SAA2) proteins, are major protein components of the Amyloid A deposits found in secondary amyloidosis. This study determines frequency of serum amyloid A2 alleles (alpha, beta) in healthy Turkish, Azerbaijan and Kazakh subjects. Two hundred Turkish, sixty five Azerbaijan and sixty five Kazakh healthy individuals were studied by previously described the PCR-RFLP methods. Our data revealed that the frequencies of the alpha and beta alleles at the SAA2 locus in the Turkish healthy population were different when compared to those in Azerbaijan and Kazakh healthy populations (p = 0.014 and p = 0.02), respectively. In contrast, the difference between alpha and beta alleles at the SAA2 locus was not different in both Kazakh and Azerbaijan healthy populations (p = 0.882).     

Biased Gene Conversion Skews Allele Frequencies in Human Populations,Increasing the Disease Burden of Recessive Alleles

Gene conversion results in the nonreciprocal transfer of genetic information between two recombining sequences, and there is evidence that this process is biased toward G and C alleles. However, the strength of GC-biased gene conversion (gBGC) in human populations and its effects on hereditary disease have yet to be assessed on a genomic scale. Using high-coverage whole-genome sequences of African hunter-gatherers, agricultural populations, and primate outgroups, we quantified the effects of GC-biased gene conversion on population genomic data sets. We find that genetic distances (F_ST and population branch statistics) are modified by gBGC. In addition, the site frequency spectrum is left-shifted when ancestral alleles are favored by gBGC and right-shifted when derived alleles are favored by gBGC. Allele frequency shifts due to gBGC mimic the effects of natural selection. As expected, these effects are strongest in high-recombination regions of the human genome. By comparing the relative rates of fixation of unbiased and biased sites, the strength of gene conversion was estimated to be on the order of Nb ≈ 0.05 to 0.09. We also find that derived alleles favored by gBGC are much more likely to be homozygous than derived alleles at unbiased SNPs (+42.2% to 62.8%). This results in a curse of the converted, whereby gBGC causes substantial increases in hereditary disease risks. Taken together, our findings reveal that GC-biased gene conversion has important population genetic and public health implications.     

人类免疫球蛋白同种异型G2M（23）因子在中国人群中的分布

应用单克隆抗体酶联免疫吸附吸附抑制实验,对我国３个民族８个群体２１０４份血样进行了免疫球蛋白同种异型Ｇ２ｍ（２３）因子检测。经多元相关和多元回归分析发现,中国人Ｇ２ｍ（２３）基因频率分布呈沿海拔高度和纬度变化的渐变群,据此建立了可预测中国人群Ｇ２Ｍ（２３）基因频率的多元回归方程,本文还讨论了Ｇ２ｍ（２３）基因频率形成渐变群的原因。     

Gene Frequencies and Heterozygosity for the AB0 and RH Blood Group Alleles in the Populations of Two Cities of Donetsk Oblast, Ukraine

The frequencies of the AB0 and RH blood group alleles and heterozygosity indices were determined for the populations of two large industrial cities of Gorlovka and Mariupol. In the population of Gorlovka the gene frequencies were as follows: AB0*0 = 0.576,AB0*A = 0.266, AB0*B = 0.158, and RH*D = 0.592, in Mariupol the frequencies were AB0*0 = 0.584, AB0*A = 0.265, AB0*B = 0.151, and RH*D = 0.604. In Gorlovka the heterozygosity indices in respect to the AB0 andRH alleles were 0.572 and 0.483, respectively; in Mariupol, 0.566 and 0.478, respectively. There were no statistically significant differences between the two populations in respect to the genetic markers analyzed. However, the heterozygosity values obtained were more similar to the corresponding estimates for some populations of Russia, than for the total population of the Ukraine.     

Serum Amyloid A Truncations in Type 2 Diabetes Mellitus

Serum Amyloid A (SAA) is an acute phase protein complex consisting of several abundant isoforms. The N- terminus of SAA is critical to its function in amyloid formation. SAA is frequently truncated, either missing an arginine or an arginine-serine dipeptide, resulting in isoforms that may influence the capacity to form amyloid. However, the relative abundance of truncated SAA in diabetes and chronic kidney disease is not known.

Methods

Using mass spectrometric immunoassay, the abundance of SAA truncations relative to the native variants was examined in plasma of 91 participants with type 2 diabetes and chronic kidney disease and 69 participants without diabetes.

Results

The ratio of SAA 1.1 (missing N-terminal arginine) to native SAA 1.1 was lower in diabetics compared to non-diabetics (p = 0.004), and in males compared to females (p<0.001). This ratio was negatively correlated with glycated hemoglobin (r = −0.32, p<0.001) and triglyceride concentrations (r = −0.37, p<0.001), and positively correlated with HDL cholesterol concentrations (r = 0.32, p<0.001).

Conclusion

The relative abundance of the N-terminal arginine truncation of SAA1.1 is significantly decreased in diabetes and negatively correlates with measures of glycemic and lipid control.     

Frequencies of four genetic polymorphisms in the CYP1A2 gene in Turkish population

Cytochrome P450 (CYP) 1A2 gene is involved in the metabolic activation of several carcinogens and altered metabolization of some clinically used drugs. We aimed to investigate the distributions of genetic polymorphisms -3860 (G/A)(CYP1A2*1C) and -2467 (T/del)(CYP1A2*1D) in the 5'-flanking region and -739 (T/G)(CYP1A2*1E) and -163(C/A)(CYP1A2*1F) in the first intron of the CYP1A2 gene in 110 unrelated healthy Turkish volunteers by PCR-RFLP technique. The frequencies of each polymorphism in Turkish population were found as 0.04, 0.92, 0.01, 0.27 for CYP1A2*1C, CYP1A2*1D, CYP1A2*1E, CYP1A2*1F, respectively. Compared with other populations, CYP1A2*1D has been found to be significantly increased in Turkish population. On the other hand, in general, the frequencies of the other polymorphisms were concordant with those in the Egyptian and Caucasian populations, and were different from those in the Japanese, Chinese and Ethiopian populations. Our results suggest that due to increased frequency of CYP1A2*1D in Turkish population, functional significance of CYP1A2*1D should be evaluated. It might be screened to determine the relationship between CYP1A2*1D and CYP1A2 related drug metabolisms in associated groups.     

Frequencies of the CCR2-64I and SDF1-3"A Alleles Associated with Progression of the HIV-1 Disease in Healthy Individuals from Moscow

The frequencies of two mutations associated with the development of clinical symptoms upon infection with human immunodeficiency virus type 1 (HIV-1) were determined in a cohort of individuals from Moscow. Allelic frequency of the first mutation, CC2-64I, causing the substitution of valine with isoleucine in the CCR2 chemokine receptor, was 0.1106 (95% confidence interval, 0.0714–0.1498). The frequency of the second mutation, the G to A substitution in the 3"-untranslated region of the stromal-derived factor 1 encoding gene, SDF1- 3"A, was 0.2125 (95% confidential interval, 0.1608–0.2642). Both values were slightly higher than those obtained earlier for Western European countries. This result can be explained by higher proportion of migrants from Asian regions, characterized by higher frequencies of these mutations, in the population of Moscow.     

Statistical Studies on Protein Polymorphism in Natural Populations. III. Distribution of Allele Frequencies and the Number of Alleles per Locus

With the aim of understanding the mechanism of maintenance of protein polymorphism, we have studied the properties of allele frequency distribution and the number of alleles per locus, using gene-frequency data from a wide range of organisms (mammals, birds, reptiles, amphibians, Drosophila and non-Drosophila invertebrates) in which 20 or more loci with at least 100 genes were sampled. The observed distribution of allele frequencies was U-shaped in all of the 138 populations (mostly species or subspecies) examined and generally agreed with the theoretical distribution expected under the mutation-drift hypothesis, though there was a significant excess of rare alleles (gene frequency, 0 ~ 0.05) in about a quarter of the populations. The agreement between the mutation-drift theory and observed data was quite satisfactory for the numbers of polymorphic (gene frequency, 0.05 ~ 0.95) and monomorphic (0.95 ~ 1.0) alleles.—The observed pattern of allele-frequency distribution was incompatible with the prediction from the overdominance hypothesis. The observed correlations of the numbers of rare alleles, polymorphic alleles and monomorphic alleles with heterozygosity were of the order of magnitude that was expected under the mutation-drift hypothesis. Our results did not support the view that intracistronic recombination is an important source of genetic variation. The total number of alleles per locus was positively correlated with molecular weight in most of the species examined, and the magnitude of the correlation was consistent with the theoretical prediction from mutation-drift hypothesis. The correlation between molecular weight and the number of alleles was generally higher than the correlation between molecular weight and heterozygosity, as expected.     

The Frequencies of Alleles of Single Nucleotide Substitutions in the CCK and CCK2R Genes in Some Russian Cattle Breeds

Russian Journal of Genetics - Allele frequencies of three substitutions in the CCK (rs42891945 and rs42891946) and CCKBR (rs42670352) genes were identified in three Russian cattle breeds: Holstein...     

Determination of Knockdown Resistance (kdr) Allele Frequencies (T929I mutation) in Head Louse Populations from Mexico,Canada, and Peru

The head louse Pediculus humanus capitis (De Geer) is a hematophagous ectoparasite that inhabits the human scalp. The infestations are asymptomatic; however, skin irritation from scratching occasionally may cause secondary bacterial infections. The present study determined the presence and frequency of the knockdown resistance (kdr) mutation T929I in 245 head lice collected from Mexico, Peru, and Canada. Head lice were collected manually using a comb in the private head lice control clinic. Allele mutation at T9291 was present in 100% of the total sampled populations (245 lice) examined. In addition, 4.89% of the lice were homozygous susceptible, whereas 6.93% heterozygous and 88.16% homozygous were resistant, respectively. This represents the second report in Mexico and Quebec and fist in Lima.     

中国西北地区汉,回,维,藏民族HLA—DRB基因多态性的研究

按照第１１届国际相容性抗原研讨会工作会议ＨＬＡⅡ类ＰＣＲ－ＳＳＯ分型标准和美国国立骨髓供者计划组织对ＨＬＡ ＤＲＢ位点等位基因分型要求,设计合成１对引物,扩增ＨＬＡ ＤＲＢ ＤＮＡ片段,长度为２５６ｂｐ,设计合成不同片段大小探针２７种,可检出ＤＲＢ座位上ＤＲＢ１的３９种等位基因,ＤＲＢ３的３种等位基因,ＤＲＢ４的１种等位基因和ＤＲＢ５的３４种等位基因。     

新型冠状病毒肺炎患者血清SAA、ESR、CRP检测结果分析

目的:分析新型冠状病毒肺炎(COVID-19)患者血清淀粉样蛋白A(SAA)、血沉ESR(ESR)、C-反应蛋白CRP(CRP)的临床价值。方法:以我院2020年1月至2020年2月确诊的COVID-19患者51例为实验组:其中重症患者21例,轻症患者30例,选取非感染患者30例为对照组。分析新型冠状病毒肺炎(COVID-19)患者血清SAA、ESR、CRP水平以及临床价值。结果:实验组SAA、ESR、CRP水平高于对照组(P0.05);重症组SAA、ESR、CRP水平高于轻症组(P0.05),由ROC曲线得知SAA、ESR、CRP预测COVID-19的AUC小于三者联合预测的AUC。结论:COVID-19的SAA、ESR、CRP水平会升高,三者联合预测为疾病评估、预测疾病发展的提供依据,值得临床进一步推广应用。     

The Survival of Mutants at Very Low Frequencies in Tribolium Populations

Forty population cages, each with 499 adult T. castaneum of the wild-type UPF strain, received a bb female newly mated with UPF males. Half of the immigrants had a Chicago Black genetic background, the other half a UPF background. These conditions simulate, respectively, the fate of a rare, genetically differing immigrant or the fate of a mutation in populations of considerable size. Adults were censused for 11 discrete generations. The semi-dominant autosomal black gene survived in 26 out of 40 cultures by the end of the experiment, demonstrating its selective advantage at these very low frequencies. The gene increased from an initial frequency of 0.002 to 0.055 (at generation 11) in at least one replicate. Although frequency-dependent fitness has been shown for black at higher frequencies, no such dependence could be demonstrated at the low frequencies of this study. The cultures simulating mutations (immigrants with native backgrounds) had a higher average gene frequency, different distribution of gene frequencies across replicates, and a lower extinction rate of black than did the cultures with alien background immigrants. The observations only partially fitted expectation based on a branching process model. The data show a tendency for the persistence of a few heterozygotes in cultures and for a deficiency of cultures that lost the mutant or those with many heterozygotes. The increase in frequency of black cannot be attributed to increased reproductive success of heterozygotes. The advantage of heterozygotes appears due to delayed developmental period as a result of tactile stimulation and probable differential cannibalism among pupae.     

The Evolution of Selectively Similar Electro-Phoretically Detectable Alleles in Finite Natural Populations

Most of the models of population genetics are not realistic when applied to data on electrophoretic variants of proteins because the same net charge may result from any of several amino acid combinations. In the absence of realistic models they have, however, been widely used to test competing hypotheses about the origin and maintenance of genetic variation in populations. In this paper I present a general method for determining probability generating functions for electrophoretic state differences. Then I use the method to find allelic state difference distributions for selectively similar electrophoretically detectable alleles in finite natural populations.Predicted patterns of genetic variation, both within and among species, are in reasonable accord with those found in the Drosophila willistoni group by Ayala et al. (1972) and by Ayala and Tracey (1974).     

The Diversity of Alleles at the Hsd Locus in Natural Populations of Escherichia Coli

In enteric bacteria three discrete families of type I restriction and modification systems (IA, IB and ID) are encoded by alleles of the serB-linked hsd locus. Probes specific for each of the three familes were used to monitor the distribution of related systems in 37 of the 72 wild-type Escherichia coli strains comprising the ECOR collection. All 25 members of group A in this collection were screened; 12 were probe-positive, nine have hsd genes in the IA family, two in the IB and one in the ID. Twelve strains, representing all groups other than A, were screened; five were probe-positive, one has hsd genes in the IA family, one in the IB and three in the ID. The type ID genes are the first representatives of this family in E. coli, the probe-negative strains could have alternative families of hsd genes. The type IA and IB systems added at least five new specificites to the five already identified in natural isolates of E. coli. The distribution of alleles is inconsistent with the dendrogram of the bacterial strains derived from other criteria. This discrepancy and the dissimilar coding sequences of allelic hsd genes both imply lateral transfer of hsd genes.