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The Inducible Defense System: Antibody Molecules and Antigen-Antibody Reactions
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
Within a single isotype, i.e., IgGl, there may be some variation in the amino acid sequence of the C region among individuals in the population. These differences are inherited genetically and determine Ig allotypes (i.e., differences among individuals of the same species). The areas with different amino acids are called allotypic markers. The markers in humans which have been defined are Gm on gamma heavy chains, Am on alpha heavy chains, and Km (or InV) on the K light chains. Three Km (on IgD and IgE), two Am (on IgA), and over twenty Gm (on IgG) allotypes have been defined. Inheritance of these markers is autosomally controlled. In some cases the molecular structure of the allotype marker is known. For example, the KM(1,2) allotype, has leucine at position 191 in the CL domain of the kappa light chain, while Km(3) allotype has valine at this position. These allotypic markers are isoantigens. They are among the epitopes that are recognized by individuals who mount an antibody response to an immunoglobulin from another individual. These allotypic markers were used in paternity testing and in studies of population genetics prior to the development of DNA-based methods.
A Comprehensive HLA-DRB, -DQB, and -DPB Oligotyping Procedure by Hybridization with Sequence-Specific Oligonucleotide Probes
Published in M. Kam, Jeffrey L. Bidwell, Handbook of HLA TYPING TECHNIQUES, 2020
Human major histocompatibility complex (MHC) class II antigens are polymorphic cell surface heterodimers encoded by distinct a and p-chain genes. They play a key role in the control of the immune response to pathogens, in transplantation immunology, and in the susceptibility to autoimmune diseases. Histocompatibility testing allows the matching of patients and donors, and the clinical outcome of organ and bone marrow transplantation depends to a large extent on the accuracy of HLA matching. Molecular biology studies of MHC genes of the last 10 years have provided the molecular basis of the extensive diversity of HLA class II antigens.12 Indeed, the analysis of the HLA-D region led to the identification of 14 to 17 nonallelic DR, DQ, DP, DM, DN, and DO genes and to the discovery of a much larger number of alleles than was originally expected.35 These studies also provided the tools to analyze HLA polymorphism directly at the DNA level (genotyping), by hybridization with sequence-specific oligonucleotide (SSO) probes (HLA oligotyping).6 The introduction of an amplification step of the target DNA by polymerase chain reaction (PCR)7,8 has rendered HLA oligotyping compatible with its use in routine HLA typing for clinical transplantation, for large-scale studies of HLA-disease associations or for population genetics.
The Nude Mutation
Published in Miroslav Holub, Immunology of Nude Mice, 2020
In terms of population genetics, it may be remembered that “… many geneticists feel that populations still maintain too much variation for selective control. If they are right …, then we must face the possibility that many genes remain in populations because selection cannot “see” them, and therefore cannot either mark them for elimination or remove other variants by favoring them. In other words, many genes may be neutral. They may be invisible to natural selection and their increase or decrease may be a result of chance alone.”8
VEGF single nucleotide polymorphisms predict improved outcome in advanced non-small cell lung cancer patients treated with platinum-based chemotherapy
Published in Journal of Chemotherapy, 2023
Huijie Qi, Wenxin Zhang, Yan Wang, Mengxi Ge, Tianxiao Wang, Liudi Zhang, Mingkang Zhong, Xiaojin Shi, Xiaohua Liang, Qiong Zhan, Qunyi Li
Linkage disequilibrium is nonrandom association of alleles at different loci. It is a sensitive indicator of the population genetic forces that constitutes a genome [36]. Previous studies have demonstrated there was strong linkage disequilibrium between rs699947, rs833061 and rs2010963 [37, 38]. Furthermore, rs833061 and rs699947 were in full linkage disequilibrium in the genotyped population of gastric cancer [37] and metastatic renal cell carcinoma [39], which is consistent with our study. It is also reported that four VEGF gene polymorphisms (rs699947, rs1570360, rs833061 and rs2010963) are in strong linkage disequilibrium [26]. Moreover, the CTC haplotype (in the following order: rs699947, rs833061 and rs2010963) is associated with risk of the diffuse histological subtype of gastric cancer [37].
High genetic complexity but low relatedness in Plasmodium falciparum infections from Western Savannah Highlands and coastal equatorial Lowlands of Cameroon
Published in Pathogens and Global Health, 2022
Ngoh Ines Atuh, Damian Nota Anong, Fru-Cho Jerome, Eniyou Oriero, Nuredin Ibrahim Mohammed, Umberto D’Alessandro, Alfred Amambua-Ngwa
The NWR and SWR attract migration from different parts of the country and from other countries including neighboring Nigeria, most especially traders. These regions are highly connected by various transportation networks, probably facilitating the sharing of infections. The SWR especially attracts tourist who come to experience its Atlantic coastal beaches, zoos and mount Cameroon sites. However, the role of human migration and its outcome on parasite population genetic structure and gene flow patterns remains unknown. Additionally, annual rainfall, temperature, topology and vegetation are particularly different between the highland grass field areas of the NWR and the coastal equatorial forest areas of the SWR [4]. It is not known if similar parasite genotypes indeed circulate across this geographical range. A few studies have examined the multiplicity of infection and/or allelic diversity of P. falciparum parasites from the South West by genotyping P. falciparum merozoite surface proteins (MSP1 and MSP2), and glutamine rich protein (GLURP) [7–10]. These studies reported significant differences in genetic diversity driven by altitude even for sites separated by only a few kilometers [8,10].
Genetic variation and population structure analysis of Chinese Wuzhong Hui population using 30 Indels
Published in Annals of Human Biology, 2020
Xing Zou, Zheng Wang, Guanglin He, Mengge Wang, Jing Liu, Shouyu Wang, Ziwei Ye, Fei Wang, Yiping Hou
Binary genetic markers, insertions and deletions (Indels), have been widely used in population genetics and forensic studies. They have distinct features, such as smaller amplicon lengths, lower mutation rates, and no stutter, which are a combination of features of short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs; Weber et al. 2002; Pereira et al. 2009). The Hui people, one of the most widespread ethnic groups in China with a population of approximately 10.5 million, are more concentrated in the north-western provinces of China, such as Ningxia, Gansu, Qinghai, and Xinjiang. Wuzhong is one of the main settlements of Hui people in Ningxia. There are 580,000 Hui people in Wuzhong, accounting for 47.2% of the total population of the city (https://en.wikipedia.org/wiki/Wuzhong,_Ningxia). In this study, we investigated the genetic diversity and population genetic substructures in Wuzhong Hui people using the 30 Indels included in the Investigator DIPplex Kit (Qiagen, Helsinki, Finland).