mutability
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- MeSH
- Escherichia coli účinky léků MeSH
- lidé MeSH
- mutace MeSH
- thymin fyziologie MeSH
- ultrafialové záření MeSH
- Check Tag
- lidé MeSH
- MeSH
- buněčné linie účinky záření MeSH
- morčata MeSH
- mutageny MeSH
- radiační genetika MeSH
- techniky in vitro MeSH
- tolerance záření MeSH
- Check Tag
- morčata MeSH
- Publikační typ
- srovnávací studie MeSH
Non-B nucleic acids structures have arisen as key contributors to genetic variation in SARS-CoV-2. Herein, we investigated the presence of defining spike protein mutations falling within inverted repeats (IRs) for 18 SARS-CoV-2 variants, discussed the potential roles of G-quadruplexes (G4s) in SARS-CoV-2 biology, and identified potential pseudoknots within the SARS-CoV-2 genome. Surprisingly, there was a large variation in the number of defining spike protein mutations arising within IRs between variants and these were more likely to occur in the stem region of the predicted hairpin stem-loop secondary structure. Notably, mutations implicated in ACE2 binding and propagation (e.g., ΔH69/V70, N501Y, and D614G) were likely to occur within IRs, whilst mutations involved in antibody neutralization and reduced vaccine efficacy (e.g., T19R, ΔE156, ΔF157, R158G, and G446S) were rarely found within IRs. We also predicted that RNA pseudoknots could predominantly be found within, or next to, 29 mutations found in the SARS-CoV-2 spike protein. Finally, the Omicron variants BA.2, BA.4, BA.5, BA.2.12.1, and BA.2.75 appear to have lost two of the predicted G4-forming sequences found in other variants. These were found in nsp2 and the sequence complementary to the conserved stem-loop II-like motif (S2M) in the 3' untranslated region (UTR). Taken together, non-B nucleic acids structures likely play an integral role in SARS-CoV-2 evolution and genetic diversity.
Co s námi bude? Kam spěje lidstvo? – jsou otázky, které si klademe snad od chvíle, kdy se počítáme mezi druh označovaný jako moudrý. Někdy právem, jindy neprávem. Lidský druh se osamostatnil v pleistocénu a vyvíjel se do dnešních dob jak po stránce živočišné, tak duševní; snad vzletnější by bylo říkat jak fyzické, tak kulturní. V naší úvaze se zabýváme otázkami o stabilitě hmoty, z níž se naše fyzické já odvozuje – naším genomem a jeho vývojem, který v pohledu nazpět lze částečně rekonstruovat, pohledem do budoucnosti jen tušit. Popisujeme zákonitosti vývoje lidského genomu a vlivy, které na něj působí; pokoušíme se je i modelovat, a porovnávat s výsledky výzkumů na zvířatech, kde máme možnost i experimentovat. To, že často docházíme k protichůdným závěrům, svědčí o tom, na jak obtížném terénu se pohybujeme, a proto i naše vývody musíme brát s velkou opatrností, neboť se velice snadno můžeme svými představami nechat zavést. Z definovaných vlivů, které působí na naše genomy jako na součásti celkového genofondu lidstva, se pokoušíme hodnotit stav mutability, mutační zátěže, kvality genů/alel, efektivní velikosti populace, a míry migrace.
Where do we go and what will happen with our genomes? Viewed as a reflection of what we know about our origin as Homo sapiens, history and forecast. Archeogenetics tries to find our sourcing place and to explain how humans occupied the globe. One of the first theories based on mtDNA polymorphisms@ studies stressed on our African origin followed by stepwise dispersal all over the world which took approximately 80 000 years. But not all findings agreed with this assumption if based on nuclear loci and supported multifocal origin of humans. The process of establishing a new species – Homo sapiens, is still not fully understood and many questions remained unanswered. From the point of view of population genetics we can assume that: 1. Mutability (natural or from internal causes) does not change though we cannot neglect suspicion that environment could influence its increase. The content of harming mutations in our genome, due to the protective effect of health care, which blocks natural selection, is increasing and moreover changes of our life style opened the door for manifestation of week deleterious alleles accumulated during foregoing period of evolution. Also prolongation of our life span is accompanied with effects of genotypes positively selected because of their positive effect on our reproductive period but which could be harmful during postreproductive stage – antagonistic pleiotropy. 2. According traditional assumption on the quality of new mutations is that they are either neutral or harming. Changes which are drift-dependent are becoming reduced. 3. Effective population size (steady state could be supposed or some increase due to more intensive local migration). 4. Migration (In spite of absence of corresponding demographic data) seems to be nowadays more intensive than it was in the past.
- MeSH
- demografie MeSH
- genetika trendy MeSH
- genom lidský MeSH
- lidé MeSH
- mutageneze genetika MeSH
- populační dynamika trendy MeSH
- stárnutí genetika MeSH
- Check Tag
- lidé MeSH
The effect of two phenolic compounds vanillin (4-hydroxy-3-methoxybenzaldehyde) and lignin on the development of drug/antibiotic resistance in Salmonella typhimurium was studied. Using the modified Ames test we have shown that vanillin alone has negligible effect on spontaneous mutability to ciprofloxacin and gentamicin resistance. At the tested concentrations vanillin reduces the toxicity of 4-nitroquinoline-N-oxide (4NQO) and reduces the ability of this compound to induce mutations leading to ciprofloxacin but not to gentamicin resistance. Lignin at higher concentrations increases mutagenicity to ciprofloxacin resistance and possess considerable inhibition effect on the spontaneous and 4NQO induced mutability to gentamicin resistance.
- MeSH
- bakteriální léková rezistence účinky léků genetika MeSH
- benzaldehydy farmakologie MeSH
- ciprofloxacin farmakologie MeSH
- fenoly farmakologie MeSH
- gentamiciny farmakologie MeSH
- lignin farmakologie MeSH
- mutace účinky léků MeSH
- Salmonella typhimurium účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In this paper we investigated the ability of 2-nitrofluorene to induce mutations leading to antibiotic resistance in quinolone-sensitive strain Salmonella typhimurium. After preincubation of bacteria with 2-nitrofluorene, the frequency of mutation to ciprofloxacin resistance was 57 fold higher than in the case of spontaneous mutability. Some of resultant resistant colonies showed a great increase of ciprofloxacin MIC.
- MeSH
- antiinfekční látky farmakologie MeSH
- bakteriální geny účinky léků MeSH
- bakteriální léková rezistence genetika MeSH
- ciprofloxacin farmakologie MeSH
- fluoreny farmakologie MeSH
- mutace účinky léků MeSH
- Salmonella typhimurium účinky léků genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
