Immunity-related genes are a suitable model for studying effects of selection at the genomic level. Some of them are highly conserved due to functional constraints and purifying selection, while others are variable and change quickly to cope with the variation of pathogens. The SLC11A1 gene encodes a transporter protein mediating antimicrobial activity of macrophages. Little is known about the patterns of selection shaping this gene during evolution. Although it is a typical evolutionarily conserved gene, functionally important polymorphisms associated with various diseases were identified in humans and other species. We analyzed the genomic organization, genetic variation, and evolution of the SLC11A1 gene in the family Equidae to identify patterns of selection within this important gene. Nucleotide SLC11A1 sequences were shown to be highly conserved in ten equid species, with more than 97 % sequence identity across the family. Single nucleotide polymorphisms (SNPs) were found in the coding and noncoding regions of the gene. Seven codon sites were identified to be under strong purifying selection. Codons located in three regions, including the glycosylated extracellular loop, were shown to be under diversifying selection. A 3-bp indel resulting in a deletion of the amino acid 321 in the predicted protein was observed in all horses, while it has been maintained in all other equid species. This codon comprised in an N-glycosylation site was found to be under positive selection. Interspecific variation in the presence of predicted N-glycosylation sites was observed.

• MeSH
• Equidae genetika   MeSH
• fylogeneze MeSH
• genomika MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• kodon genetika   MeSH
• molekulární evoluce * MeSH
• proteiny přenášející kationty genetika   MeSH
• selekce (genetika) genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• dítě MeSH
• efektivita organizační MeSH
• kvalita zdravotní péče MeSH
• laryngoskopie MeSH
• péče o pacienty v kritickém stavu MeSH
• pooperační péče MeSH
• výsledek terapie MeSH
• Check Tag
• dítě MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• dětská chirurgie
• otorinolaryngologie
• NLK Publikační typ
• brožury

• MeSH
• dechová terapie MeSH
• ventilace umělá s přerušovaným přetlakem MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• pneumologie a ftizeologie

• MeSH
• dítě MeSH
• esenciální léky aplikace a dávkování   MeSH
• informační služby o lécích MeSH
• spotřeba léčiv MeSH
• Check Tag
• dítě MeSH

• Konspekt
• Farmacie. Farmakologie
• NLK Obory
• pediatrie
• farmacie a farmakologie
• farmacie a farmakologie
• NLK Publikační typ
• publikace WHO

Targeting mutations to specific genomic loci is invaluable for assessing in vivo the effect of these changes on the biological role of the gene in study. Here, we attempted to introduce a mutation that was previously implicated in an increased heat stability of the mesophilic cyanobacterium Synechocystis sp. PCC6803 via homologous recombination to the psbA gene of Chlamydomonas reinhardtii. For that, we established a strategy for targeted mutagenesis that was derived from the efficient genome-wide homologous-recombination-based methodology that was used to target individual genes of Saccharomyces cerevisiae. While the isolated mutants did not show any benefit under elevated temperature conditions, the new strategy proved to be efficient for C. reinhardtii even in the absence of direct positive selection.

• MeSH
• Chlamydomonas reinhardtii genetika   MeSH
• fotosystém II (proteinový komplex) genetika   MeSH
• geneticky modifikované rostliny genetika   MeSH
• genom plastidový genetika   MeSH
• homologní rekombinace MeSH
• mutageneze cílená metody   MeSH
• rostlinné proteiny genetika   MeSH
• selekce (genetika) MeSH
• serin genetika   MeSH
• substituce aminokyselin MeSH
• Synechocystis genetika   MeSH
• termotolerance genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND AND AIMS: The centromere drive theory explains diversity of eukaryotic centromeres as a consequence of the recurrent conflict between centromeric repeats and centromeric histone H3 (CenH3), in which selfish centromeres exploit meiotic asymmetry and CenH3 evolves adaptively to counterbalance deleterious consequences of driving centromeres. Accordingly, adaptively evolving CenH3 has so far been observed only in eukaryotes with asymmetric meiosis. However, if such evolution is a consequence of centromere drive, it should depend not only on meiotic asymmetry but also on monocentric or holokinetic chromosomal structure. Selective pressures acting on CenH3 have never been investigated in organisms with holokinetic meiosis despite the fact that holokinetic chromosomes have been hypothesized to suppress centromere drive. Therefore, the present study evaluates selective pressures acting on the CenH3 gene in holokinetic organisms for the first time, specifically in the representatives of the plant genus Luzula (Juncaceae), in which the kinetochore formation is not co-localized with any type of centromeric repeat. METHODS: PCR, cloning and sequencing, and database searches were used to obtain coding CenH3 sequences from Luzula species. Codon substitution models were employed to infer selective regimes acting on CenH3 in Luzula KEY RESULTS: In addition to the two previously published CenH3 sequences from L. nivea, 16 new CenH3 sequences have been isolated from 12 Luzula species. Two CenH3 isoforms in Luzula that originated by a duplication event prior to the divergence of analysed species were found. No signs of positive selection acting on CenH3 in Luzula were detected. Instead, evidence was found that selection on CenH3 of Luzula might have been relaxed. CONCLUSIONS: The results indicate that holokinetism itself may suppress centromere drive and, therefore, holokinetic chromosomes might have evolved as a defence against centromere drive.

• MeSH
• centromera genetika   MeSH
• chromozomy rostlin genetika   MeSH
• fylogeneze MeSH
• genom rostlinný genetika   MeSH
• histony genetika   MeSH
• Magnoliopsida genetika   MeSH
• meióza genetika   MeSH
• sekvenční analýza DNA MeSH
• sekvenční seřazení MeSH
• selekce (genetika) genetika   MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Understanding the mechanisms and selective forces leading to adaptive radiations and origin of biodiversity is a major goal of evolutionary biology. Acrocephalus warblers are small passerines that underwent an adaptive radiation in the last approximately 10 million years that gave rise to 37 extant species, many of which still hybridize in nature. Acrocephalus warblers have served as model organisms for a wide variety of ecological and behavioral studies, yet our knowledge of mechanisms and selective forces driving their radiation is limited. Here we studied patterns of interspecific gene flow and selection across three European Acrocephalus warblers to get a first insight into mechanisms of radiation of this avian group. RESULTS: We analyzed nucleotide variation at eight nuclear loci in three hybridizing Acrocephalus species with overlapping breeding ranges in Europe. Using an isolation-with-migration model for multiple populations, we found evidence for unidirectional gene flow from A. scirpaceus to A. palustris and from A. palustris to A. dumetorum. Gene flow was higher between genetically more closely related A. scirpaceus and A. palustris than between ecologically more similar A. palustris and A. dumetorum, suggesting that gradual accumulation of intrinsic barriers rather than divergent ecological selection are more efficient in restricting interspecific gene flow in Acrocephalus warblers. Although levels of genetic differentiation between different species pairs were in general not correlated, we found signatures of apparently independent instances of positive selection at the same two Z-linked loci in multiple species. CONCLUSIONS: Our study brings the first evidence that gene flow occurred during Acrocephalus radiation and not only between sister species. Interspecific gene flow could thus be an important source of genetic variation in individual Acrocephalus species and could have accelerated adaptive evolution and speciation rate in this avian group by creating novel genetic combinations and new phenotypes. Independent instances of positive selection at the same loci in multiple species indicate an interesting possibility that the same loci might have contributed to reproductive isolation in several speciation events.

• MeSH
• biodiverzita MeSH
• biologická evoluce MeSH
• fenotyp MeSH
• genetická variace MeSH
• hybridizace genetická MeSH
• pohlavní chromozomy * MeSH
• reprodukční izolace MeSH
• selekce (genetika) * MeSH
• tok genů * MeSH
• vznik druhů (genetika) MeSH
• zpěvní ptáci genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Evropa MeSH

Behavioural isolation may lead to complete speciation when partial postzygotic isolation acts in the presence of divergent-specific mate-recognition systems. These conditions exist where Mus musculus musculus and M. m. domesticus come into contact and hybridize. We studied two mate-recognition signal systems, based on urinary and salivary proteins, across a Central European portion of the mouse hybrid zone. Introgression of the genomic regions responsible for these signals: the major urinary proteins (MUPs) and androgen binding proteins (ABPs), respectively, was compared to introgression at loci assumed to be nearly neutral and those under selection against hybridization. The preference of individuals taken from across the zone regarding these signals was measured in Y mazes, and we develop a model for the analysis of the transition of such traits under reinforcement selection. The strongest assortative preferences were found in males for urine and females for ABP. Clinal analyses confirm nearly neutral introgression of an Abp locus and two loci closely linked to the Abp gene cluster, whereas two markers flanking the Mup gene region reveal unexpected introgression. Geographic change in the preference traits matches our reinforcement selection model significantly better than standard cline models. Our study confirms that behavioural barriers are important components of reproductive isolation between the house mouse subspecies.

• MeSH
• alely MeSH
• chování zvířat MeSH
• genetické lokusy genetika   MeSH
• genetické markery MeSH
• hybridizace genetická MeSH
• modely genetické MeSH
• myši MeSH
• posilování (psychologie) MeSH
• pravděpodobnostní funkce MeSH
• savčí chromozomy genetika   MeSH
• selekce (genetika) MeSH
• zeměpis MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geografické názvy
• Evropa MeSH

A positive selection system using phosphomannose isomerase was employed for Agrobacterium tumefaciens mediated transformation of lettuce (Lactuca sativa L. var. 'Achát'). It was shown that the mannose-based selection system works very well with the lettuce genotype used, reaching up to 25% transformation efficiency on the medium with 20 g/L mannose and 20 g/L sucrose. The best transformation efficacy with the commonly-used kanamycin at 100 mg/L as a selection agent was 21%. Southern blot analyses of thirteen chosen mannose-resistant regenerants revealed that some of them have clonal origin, about one-half harbour a single T-DNA copy and one plant contains an incomplete T-DNA segment with only the left part of T-DNA with the pmi gene present in the genomic DNA. The following Northern analysis showed transcriptional activity of the introduced pmi gene in all plants analysed with very high differences in the level of pmi specific mRNA. The results demonstrate that both mannose and kanamycin provide comparable transformation efficiencies in our lettuce genotype. An alternative selection method with mannose as a selection agent is now available for lettuce transgenosis.

• MeSH
• Agrobacterium tumefaciens genetika   MeSH
• geneticky modifikované rostliny MeSH
• mannosa-6-fosfátisomerasa genetika   MeSH
• salát (hlávkový) enzymologie   genetika   růst a vývoj   MeSH
• selekce (genetika) MeSH
• transformace genetická MeSH
• výhonky rostlin enzymologie   genetika   růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Úvod: Řada studií prokázala vliv srdeční resynchronizační léčby (CRT) na zlepšení funkčního stavu a navození reverzní remodelace levé komory. Při současných indikačních kritériích je popisováno až 30–40 % pacientů nereagujících na CRT, tzv. non-responderů. Cíl: U pacientů s přístroji CRT posoudit vliv CRT na změnu funkční třídy NYHA a na změnu echokardiografi ckých parametrů, posoudit vliv etiologie srdečního selhání a vstupního rytmu a stanovit predikční schopnost šířky komplexu QRS a parametrů komorové dyssynchronie na účinek CRT. Pacienti a metody: Bylo hodnoceno 194 pacientů po úspěšné implantaci přístroje CRT. Stanovení funkční třídy NYHA, šířky komplexu QRS a echokardiografi ckých parametrů včetně parametrů komorové dyssynchronie (SPWMD – septal-to-posterior wall motion delay, Ts-bas-lat – časový rozdíl v maximální systolické rychlosti septa a laterální stěny v TDI zobrazení, IVMD – interventrikulární mechanické zpoždění) provedeno před implantací a tři měsíce, příp. 12 měsíců po implantaci. Výsledky: Zlepšení funkční třídy NYHA tři měsíce po implantaci bylo významné oproti stavu před implantací a významně lepší než stav 12 měsíců po implantaci. Responderů (pacienti se zlepšením třídy NYHA) bylo 61 %, resp. 49 % po třech, resp. 12 měsících po implantaci. Respondeři vykazovali zlepšení ejekční frakce (LVEF) a zmenšení end-diastolického a end-systolického rozměru (LVEDD, LVESD) na rozdíl od non-responderů. Účinek CRT byl srovnatelný u pacientů s ischemickou a neischemickou kardiomyopatií a horší u pacientů s fi brilací síní ve srovnání s pacienty se sinusovým rytmem. Zlepšení parametrů komorové dyssynchronie bylo patrné u všech podskupin pacientů. Šířka komplexu QRS a SPWMD vykazovaly relativně dobrou senzitivitu, ale špatnou specifi citu, IVMD naopak. Šířka komplexu QRS a IVMD měly lepší výpovědní hodnotu u pacientů s neischemickou kardiomyopatií. Závěr: CRT vede ke zlepšení třídy NYHA, LVEF, LVEDD a LVESD. Zlepšení je patrno jen u responderů. Účinek CRT se neliší podle etiologie srdečního selhání. Pacienti s fi brilací síní profi tují z CRT méně. Žádný z testovaných parametrů komorové dyssynchronie nevykazoval dobrou predikční schopnost. Naše závěry jsou podobné s výsledky multicentrické kontrolované studie PROSPECT a SCART.

Introduction: A number of studies have documented the eff ect of cardiac resynchronization therapy (CRT) on improving functional status and inducing reverse left ventricular remodeling. Using current indication criteria, the proportion of non-responders, i.e., those not responding to CRT, has been reported to be 30–40%. Aim: To assess, in patients with CRT devices, the eff ect of CRT on changes in NYHA class and echocardiographic parameters, to assess the eff ect of heart failure etiology and baseline rhythm, and to determine the ability of QRS width and ventricular dyssynchrony parameters to predict the eff ect of CRT. Patients and methods: A total of 194 patients with successful CRT device implantation were evaluated. Their NYHA class, QRS width and echocardiographic parameters including those of ventricular dyssynchrony (septal-to-posterior wall motion delay [SPWMD], time diff erence in peak systolic septal-to-lateral wall velocity in tissue Doppler imaging [Ts-bas-lat], and interventricular mechanical delay [IVMD]) were determined prior to implantation and at 3 and/or 12 months after the procedure. Results: The improvement in NYHA class at 3 months was signifi cant compared with baseline, and signifi cant compared with 12 months post-implant. There were 61% and 49% of responders (patients with improved NYHA class) at 3 and 12 months post-implant, respectively. Compared with non-responders, responders showed improved left ventricular ejection fraction (LVEF) and decreased end-diastolic and end-systolic dimensions (LVEDD, LVESD). The eff ect of CRT was comparable in patients with ischemic and non-ischemic cardiomyopathy, and CRT was less eff ective in patients with atrial fi brillation versus those with sinus rhythm. The improvement in ventricular dyssynchrony parameters was apparent in all patient subpopulations. QRS width and SPWMD showed relatively good sensitivity but poor specifi city whereas this was just the opposite with IVMD. The predictive power of QRS width and IVMD was higher in patients with non-ischemic cardiomyopathy. Conclusion: Cardiac resynchronization therapy improves NYHA class, LVEF, LVEDD, and LVESD; however, the improvement is apparent only in responders. The eff ect of CRT is not dependent on the etiology of heart failure. The benefi t of CRT is less in patients with atrial fi brillation. None of the tested parameters of ventricular dyssynchrony showed a good predictive power. Our conclusions are similar to those reported by the multicenter controlled PROSPECT and SCART trials.

• Klíčová slova
• Komorová dyssynchronie, Výběr kandidátů CRT,
• MeSH
• dysfunkce levé srdeční komory terapie   MeSH
• echokardiografie využití   MeSH
• lidé MeSH
• prediktivní hodnota testů MeSH
• prostředky srdeční resynchronizační terapie využití   MeSH
• remodelace komor MeSH
• senzitivita a specificita MeSH
• srdeční resynchronizační terapie metody   MeSH
• srdeční selhání terapie   MeSH
• stupeň závažnosti nemoci MeSH
• výběr pacientů MeSH
• Check Tag
• lidé MeSH