scholarly journals Molecular Identification and Appraisal of the Genetic Variation of Taenia saginata in Central Regions of Vietnam

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 70
Author(s):  
Giang Tran Thi ◽  
Ilenia Azzena ◽  
Fabio Scarpa ◽  
Piero Cossu ◽  
Cong Danh Le ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Mitochondrial Gene ◽  
Lao Pdr ◽  
Human Populations ◽  
Taenia Saginata ◽  
Asian Countries ◽  
Central Regions ◽  
Coi Sequences ◽  
Globally Distributed ◽  
Insight Into

Taenia saginata is a globally distributed tapeworm responsible for human taeniasis due to the ingestion of raw or undercooked beef. T. saginata is present in several Asian countries, including China, Thailand, Lao PDR, Cambodia, and Vietnam, but little is known about its genetic variation. Studying the tapeworm’s phylogeographic patterns is crucial to better understanding their association with the geographic distribution of taeniasis/cysticercosis in human populations. In the present study, 38 specimens of this putative species were collected in central regions of Vietnam and analysed using the mitochondrial gene Cytochrome c Oxidase subunit I (COI) as a molecular marker to assess the correct species identification and investigate the level of genetic variation at different geographic scales. Phylogenetic and phylogeographic analyses were carried out on a dataset that included COI sequences from Vietnamese specimens and from all conspecifics available in GenBank to date. The results showed that the collected Vietnamese specimens belonged to the species T. saginata. In Southeast Asia, signs of a possible founder effect were discovered, with the most common haplotypes frequent and present in many countries, except Lao PDR, which shares its most common haplotype only with individuals from Thailand. Remarkably, a unique taxonomic entity was found worldwide, even though the available COI sequences of T. saginata belonging to non-Asiatic countries are, at present, limited. Therefore, future studies including more COI sequences from a higher number of countries and the use of a combined molecular approach with multiple genetic markers would be useful to provide deeper insight into the global genetic variation of this species.

scholarly journals Characterization of X-Linked SNP genotypic variation in globally distributed human populations

2010 ◽  
Vol 11 (1) ◽  
pp. R10 ◽  
Author(s):  
Amanda M Casto ◽  
Jun Z Li ◽  
Devin Absher ◽  
Richard Myers ◽  
Sohini Ramachandran ◽  
...  
Keyword(s):  
Genotypic Variation ◽  
Human Populations ◽  
Globally Distributed

scholarly journals Different historical generation intervals in human populations inferred from Neanderthal fragment lengths and patterns of mutation accumulation

2021 ◽  
Author(s):  
Moisès Coll Macià ◽  
Laurits Skov ◽  
Benjamin Marco Peter ◽  
Mikkel Heide Schierup
Keyword(s):  
Fragment Length ◽  
Human Populations ◽  
Female Age ◽  
Generation Interval ◽  
The Past ◽  
Geographical Regions ◽  
Neanderthal Admixture ◽  
Rate Of Decay ◽  
Out Of Africa ◽  
Insight Into

AbstractAfter the main out-of-Africa event, humans interbred with Neanderthals leaving 1-2% of Neanderthal DNA scattered in small fragments in all non-African genomes today1,2. Here we investigate the size distribution of these fragments in non-African genomes3. We find consistent differences in fragment length distributions across Eurasia with 11% longer fragments in East Asians than in West Eurasians. By comparing extant populations and ancient samples, we show that these differences are due to a different rate of decay in length by recombination since the Neanderthal admixture. In line with this, we observe a strong correlation between the average fragment length and the accumulation of derived mutations, similar to what is expected by changing the ages at reproduction as estimated from trio studies4. Altogether, our results suggest consistent differences in the generation interval across Eurasia, by up to 20% (e.g. 25 versus 30 years), over the past 40,000 years. We use sex-specific accumulations of derived alleles to infer how these changes in generation intervals between geographical regions could have been mainly driven by shifts in either male or female age of reproduction, or both. We also find that previously reported variation in the mutational spectrum5 may be largely explained by changes to the generation interval and not by changes to the underlying mutational mechanism. We conclude that Neanderthal fragment lengths provide unique insight into differences of a key demographic parameter among human populations over the recent history.

scholarly journals Genomic and demographic processes differentially influence genetic variation across the X chromosome

2021 ◽  
Author(s):  
Daniel J. Cotter ◽  
Timothy H. Webster ◽  
Melissa A. Wilson
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Linkage Disequilibrium ◽  
X Chromosome ◽  
Global Scale ◽  
Careful Consideration ◽  
Human Populations ◽  
Evolutionary Forces ◽  
Ideal System ◽  
Demographic Patterns

AbstractMutation, recombination, selection, and demography affect genetic variation across the genome. Increased mutation and recombination both lead to increases in genetic diversity in a region-specific manner, while complex demographic patterns shape patterns of diversity on a more global scale. The X chromosome is particularly interesting because it contains several distinct regions that are subject to different combinations and strengths of these processes, notably the pseudoautosomal regions (PARs) and the X-transposed region (XTR). The X chromosome thus can serve as a unique model for studying how genetic and demographic forces act in different contexts to shape patterns of observed variation. Here we investigate diversity, divergence, and linkage disequilibrium in each region of the X chromosome using genomic data from 26 human populations. We find that both diversity and substitution rate are consistently elevated in PAR1 and the XTR compared to the rest of the X chromosome. In contrast, linkage disequilibrium is lowest in PAR1 and highest on the non-recombining X chromosome, with the XTR falling in between, suggesting that the XTR (usually included in the non-recombining X) may need to be considered separately in future studies. We also observed strong population-specific effects on genetic diversity; not only does genetic variation differ on the X and autosomes among populations, but the effects of linked selection on the X relative to autosomes have been shaped by population-specific history. The substantial variation in patterns of variation across these regions provides insight into the unique evolutionary history contained within the X chromosome.Significance StatementDemography and selection affect the X chromosome differently from non-sex chromosomes. However, the X chromosome can be subdivided into multiple distinct regions that facilitate even more fine-scaled assessment of these processes. Here we study regions of the human X chromosome in 26 populations to find evidence that recombination may be mutagenic in humans and that the X-transposed region may undergo recombination. Further we observe that the effects of selection and demography act differently on the X chromosome relative to the autosomes across human populations. Together, our results highlight profound regional differences across the X chromosome, simultaneously making it an ideal system for exploring the action of evolutionary forces as well as necessitating its careful consideration and treatment in genomic analyses.

scholarly journals Investigation of the genetic variation in ACE2 on the structural recognition by the novel coronavirus (SARS-CoV-2)

2020 ◽  
Author(s):  
Xingyi Guo ◽  
Zhishan Chen ◽  
Yumin Xia ◽  
Weiqiang Lin ◽  
Hongzhi Li
Keyword(s):  
Genetic Variation ◽  
The Novel ◽  
S Protein ◽  
Angiotensin Converting Enzyme 2 ◽  
Missense Variants ◽  
Catalytic Metal ◽  
Using Data ◽  
Novel Coronavirus ◽  
Insight Into

Abstract Background: The outbreak of coronavirus disease (COVID-19) was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), through its surface spike glycoprotein (S-protein) recognition on the receptor Angiotensin-converting enzyme 2 (ACE2) in humans. However, it remains unclear how genetic variations in ACE2 may affect its function and structure, and consequently alter the recognition by SARS-CoV-2. Methods: We have systemically characterized missense variants in the gene ACE2 using data from the Genome Aggregation Database (gnomAD; N = 141,456). To investigate the putative deleterious role of missense variants, six existing functional prediction tools were applied to evaluate their impact. We further analyzed the structural flexibility of ACE2 and its protein-protein interface with the S-protein of SARS-CoV-2 using our developed Legion Interfaces Analysis (LiAn) program.Results: Here, we characterized a total of 12 ACE2 putative deleterious missense variants. Of those 12 variants, we further showed that p.His378Arg could directly weaken the binding of catalytic metal atom to decrease ACE2 activity and p.Ser19Pro could distort the most important helix to the S-protein. Another seven missense variants may affect secondary structures (i.e. p.Gly211Arg; p.Asp206Gly; p.Arg219Cys; p.Arg219His, p.Lys341Arg, p.Ile468Val, and p.Ser547Cys), whereas p.Ile468Val with AF = 0.01 is only present in Asian.Conclusions: We provide strong evidence of putative deleterious missense variants in ACE2 that are present in specific populations, which could disrupt the function and structure of ACE2. These findings provide novel insight into the genetic variation in ACE2 which may affect the SARS-CoV-2 recognition and infection, and COVID-19 susceptibility and treatment.

scholarly journals An insight into the polymeric structures in Asian Palmyra palm (Borassus flabellifer Linn)

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Paulraj Mosae Selvakumar ◽  
Rex Jeya Rajkumar Samdavid Thanapaul
Keyword(s):  
Climatic Conditions ◽  
Palm Tree ◽  
Asian Countries ◽  
Current Review ◽  
Medicinal Value ◽  
Native Tree ◽  
Polymeric Compounds ◽  
Value Add ◽  
Polymeric Structures ◽  
Insight Into

Palmyra Palm (Borassus flabellifer Linn) is a native tree with various ecological, medicinal, economic, and sociological benefits from Asian countries. Palmyra Palm tree-based self-reliant lifestyle and Eco-friendly community living which leads to sustainable development can be called as palmyraculture. For each component, it is the most beneficial species that has economic and medicinal value that could sustain adverse climatic conditions and resist natural calamities. Non-edible, edible, and value add-based uses could be widely categorized into the utility of the plant. Palmyra palm tree is working like a non-stop biochemical factory, creates sugars and many other useful chemicals. They also produce many useful polymeric compounds such as pectin, cellulose, hemicellulose, galactomannan, pentosan, polyphenols, and lignin. The current review gives an insight into the structural, biological and polymeric elements of Asian palmyra. . 

scholarly journals Asia Science and Technology Portals

2018 ◽  
Vol 155 ◽  
pp. 01034 ◽  
Author(s):  
Phonepaseuth Solinthone ◽  
Tatiana Rumyantseva ◽  
Anachack Phongtraychack
Keyword(s):  
Science And Technology ◽  
Lao Pdr ◽  
Asian Countries ◽  
Web Portal ◽  
Related Information ◽  
Further Development

The article presents the information about science and technology portals in Asian countries and their role in dissemination of science and technology-related information. The article describes a new Lao Science and Technology Web Portal launched by the Ministry of Science and Technology of Lao PDR in 2017. The authors analyze goals, content, functions, and benefits of the Lao Science and Technology Web portal as well as problems suppressing its further development.

scholarly journals The emergence of latent infection in the early evolution of Mycobacterium tuberculosis

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160499 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
Mark M. Tanaka
Keyword(s):  
Mathematical Model ◽  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Genetic Variation ◽  
Natural Selection ◽  
Natural History ◽  
Latent Infection ◽  
Human Populations ◽  
Safe Harbour ◽  
Active Disease

Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured.

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