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Parasites and Conservation Biology
Published in Eric S. Loker, Bruce V. Hofkin, Parasitology, 2023
Eric S. Loker, Bruce V. Hofkin
Loss of genetic diversity might have a general effect that ultimately limits the ability of individuals in the population to mount effective immune responses or it might more specifically affect immune genes directly responsible for recognizing and resisting parasites. For instance, recall from Chapters 4 and 7 that proteins encoded by loci of the major histocompatibility complex (MHC) play a major role in antigen presentation in the vertebrate adaptive immune response. MHC genes are highly polymorphic and many variant alleles are present in a typical population. If a population lacks genetic diversity, its repertoire of MHC alleles may be limited, potentially limiting its ability to present antigens derived from some parasites. The relative roles of general inbreeding depression and of reduced diversity in specific immune loci such as the MHC are often not easily teased apart in conservation studies of species endangered by parasite attack.
“Omics” Technologies in Vaccine Research
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Efficacy of the candidate antigens is desired to be valid for the majority of the target population. Therefore, polymorphisms should be considered in the selection process of the antigens. For this purpose, single nucleotide polymorphisms (SNPs) are analyzed for a set of transcripts to find out the genetic diversity. However, it is important to be cautious that the bioinformatic tool used for the analysis may identify the variants having polymorphism at one or more positions as different transcripts (Contreras et al. 2018). Additionally, polymorphisms in the genes related with immune responses, such as the genes encoding toll-like receptors (TLRs), might also have influence on the success of the vaccine (Buonaguro and Pulendran 2011).
Healthy People / Immuno-enhancement
Published in Jonathan Anomaly, Creating Future People, 2020
A simple example involves the sickle cell trait. When children are born with one allele (genetic variant) of the trait, they exhibit resistance to malaria. But when they inherit the same allele from both parents, they produce abnormal (sickle-shaped) blood cells that create a variety of health risks. According to the recent report by the Nuffield Council on Bioethics: The persistence of the recessive sickle cell trait … appears to be a consequence of its protective effect against malaria. Thus, although it causes serious disease in some cases, elimination of the trait from the population would probably have negative consequences at the population level if malaria were present. The value of genetic diversity is thus not limited to individual well-being, but to the human population as a whole and its susceptibility to disease.(2018, p. 11)
The mitochondrial DNA HVI and HVII sequences and haplogroup distribution in a population sample from Vietnam
Published in Annals of Human Biology, 2022
Nam Ngoc Nguyen, Trong Luc Hoang, Trang Hong Nguyen, Phuong Thi Le, Chi Hung Nguyen, Viet Vinh Tran, Hoang Ha Chu, Ha Hoang
A total of 145 different haplotypes were determined based on the HVI and HVII sequence data of 173 Vietnamese individuals. The haplotype information is shown in Table S2 and statistical parameters are presented in Table 1. Among 145 haplotypes, 138 were found to be unique (occurred only once) and 17 were shared by two to eight individuals. The population sample in this study had the random match probability (RMP) of 0.96%, which is higher compared to that of 0.90% and 0.37% from different Vietnamese populations as reported previously (Irwin et al. 2008; Tran et al. 2018). An explanation for this is the high presence of the haplotype 73 G 249DEL 263 G 315.1 C 16108 T 16129 A 16162 G 16172 C 16304 C (8 times) and 73 G 249DEL 263 G 315.1 C 16129 A 16172 C 16304 C (5 times) in the dataset, leading to an increase in RMP. These two haplotypes are widely distributed in Southeast and East Asian populations and presented at high frequencies in Vietnam, Thailand, Laos, Malaysia, Indonesia, and China when being searched against the EMPOP database. Nevertheless, the genetic diversity estimated in this study (0.9962) is comparable with data from Irwin et al. (2008; 0.9964) and Tran et al. (2018; 0.9983). Additionally, the power of discrimination (PD) of 0.9904 is relatively high, suggesting the usefulness of this dataset for forensic analyses.
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
A haploid dataset comprising only the dominant alleles (major electropherogram peaks) was used to report all further population genetic analysis as previously reported [23,26]. The population level genetic diversity was estimated from the Nei unbiased expected heterozygosity (He) and Linkage disequilibrium (LD) following 1000 permutations using the poppr package in R [27]. Poppr derives the He for each population as, n is the number of samples genotyped and Pi is the frequency of any ith allele at a locus for the specific population. He has a potential range from 0 (no allele diversity) to 1 (all sampled alleles are different). Multi-locus LD was calculated within populations as the standard index of association (ISA) [28], to determine if similar multi-locus haplotypes were detected in populations. ISA = (1/n – 1 ((VD/(VE) – 1), where n is the number of loci for which two individuals differ, VE and VD are the expected and observed variance respectively. Values range from 0 (no loci in LD) to 1 (all loci in LD). The Monte Carlo method was used to test for statistical significance.
Population genetic data for 12 X-STR loci in the Central Saudi region using investigator Argus X-12 amplification kit
Published in Annals of Human Biology, 2021
Safia A. Messaoudi, Saranya R. Babu, Abrar B. Alsaleh, Mohammed Albujja, Noora R. Al-Snan, Abdul Rauf Chaudhary, Ahmed Ch. Kassab, Mourad Assidi
The majority of Saudi Arabian Y-chromosome composition has been reported to be of Levantine origins (69%); with significant contributions from the East via Iran (17%), and Africa (14%) (Abu-Amero et al. 2009). This geographical and social organisation might be expected to have an effect on patterns of genetic diversity. However, allele/haplotype frequency data of forensically relevant X-STR markers in Saudi Arabia are extremely limited. The forensic and human identity testing potential of X-STRs is due to the inheritance pattern of the X-chromosome compared to other genetic markers (Szibor 2007). Among haploid markers and in addition to STRs, stable haplotypes of closely associated X-chromosome markers have proven to be a powerful, highly informative and particularly important tool in the analysis of complex kinship cases, where one or more females are involved. Such cases may benefit from the use of X-STRs which can also be applied to solve cases of missing persons, criminal incest, immigration, paternity deficiency or other similar situations (Diegoli and Coble 2015).