Despite the homogenizing effect of strong gene flow between two populations, adaptation under symmetric divergent selection pressures results in partial reproductive isolation: adaptive substitutions act as local barriers to gene flow, and if divergent selection continues unimpeded, this will result in complete reproductive isolation of the two populations, i.e. speciation. However, a key issue in framing the process of speciation as a tension between local adaptation and the homogenizing force of gene flow is that the mutation process is blind to changes in the environment and therefore tends to limit adaptation. Here we investigate how globally beneficial mutations (GBMs) affect divergent local adaptation and reproductive isolation. When phenotypic divergence is finite, we show that the presence of GBMs limits local adaptation, generating a persistent genetic load at the loci that contribute to the trait under divergent selection and reducing genome-wide divergence. Furthermore, we show that while GBMs cannot prohibit the process of continuous differentiation, they induce a substantial delay in the genome-wide shutdown of gene flow. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

• Klíčová slova
• divergent selection, ecological speciation, gene flow, local adaptation, reproductive isolation,
• MeSH
• biologická adaptace genetika   MeSH
• modely genetické MeSH
• reprodukční izolace * MeSH
• selekce (genetika) fyziologie   MeSH
• tok genů * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Czech Air-Force prepares an introduction of a new generation of aircraft with high maneuvering possibilities. The possibility of making full use of the aircraft flight properties assumes sufficient pilot's +Gz tolerance and also its improvement during the new flight training system. The optimal method to achieve this purpose is the human centrifuge utilization. For the Czech Republic, the building or the renting of a human centrifuge for the pilot's selection is unfortunately very expensive. In our institute we are interested in the analysis of the possibilities of the lower body negative pressure (LBNP) technique for the basic pilot's selection with low level of +Gz tolerance, using the examination of the orthostatic cardiovascular reactions of the pilot's organism.

• MeSH
• abdominální dekomprese * MeSH
• hypergravitace * MeSH
• krevní tlak fyziologie   MeSH
• letadla MeSH
• letecké a kosmické lékařství MeSH
• lidé MeSH
• ozbrojené síly MeSH
• pletysmografie MeSH
• srdeční frekvence MeSH
• výběr pracovníků * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).

• Klíčová slova
• Sahel, admixture, genome-wide diversity, selection,
• MeSH
• acetyltransferasy genetika   MeSH
• genom lidský * MeSH
• haplotypy MeSH
• hemoragické horečky virové genetika   MeSH
• jednonukleotidový polymorfismus MeSH
• krevní skupiny - systém Duffy genetika   MeSH
• lidé MeSH
• malárie genetika   MeSH
• MCM komplex, komponenta 6 genetika   MeSH
• meningitida genetika   MeSH
• migrace lidstva * MeSH
• proteiny buněčného cyklu MeSH
• proteiny genetika   MeSH
• receptory buněčného povrchu genetika   MeSH
• receptory spřažené s G-proteiny genetika   MeSH
• selekce (genetika) * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Afrika MeSH
• Názvy látek
• acetyltransferasy MeSH
• ACKR1 protein, human MeSH Prohlížeč
• ALMS1 protein, human MeSH Prohlížeč
• krevní skupiny - systém Duffy MeSH
• MCM komplex, komponenta 6 MeSH
• MCM6 protein, human MeSH Prohlížeč
• NAT8 protein, human MeSH Prohlížeč
• proteiny buněčného cyklu MeSH
• proteiny MeSH
• receptory buněčného povrchu MeSH
• receptory spřažené s G-proteiny MeSH
• TAS2R1 protein, human MeSH Prohlížeč

OBJECTIVES: Genome-wide meta-analyses of clinically defined gout were performed to identify subtype-specific susceptibility loci. Evaluation using selection pressure analysis with these loci was also conducted to investigate genetic risks characteristic of the Japanese population over the last 2000-3000 years. METHODS: Two genome-wide association studies (GWASs) of 3053 clinically defined gout cases and 4554 controls from Japanese males were performed using the Japonica Array and Illumina Array platforms. About 7.2 million single-nucleotide polymorphisms were meta-analysed after imputation. Patients were then divided into four clinical subtypes (the renal underexcretion type, renal overload type, combined type and normal type), and meta-analyses were conducted in the same manner. Selection pressure analyses using singleton density score were also performed on each subtype. RESULTS: In addition to the eight loci we reported previously, two novel loci, PIBF1 and ACSM2B, were identified at a genome-wide significance level (p<5.0×10-8) from a GWAS meta-analysis of all gout patients, and other two novel intergenic loci, CD2-PTGFRN and SLC28A3-NTRK2, from normal type gout patients. Subtype-dependent patterns of Manhattan plots were observed with subtype GWASs of gout patients, indicating that these subtype-specific loci suggest differences in pathophysiology along patients' gout subtypes. Selection pressure analysis revealed significant enrichment of selection pressure on ABCG2 in addition to ALDH2 loci for all subtypes except for normal type gout. CONCLUSIONS: Our findings on subtype GWAS meta-analyses and selection pressure analysis of gout will assist elucidation of the subtype-dependent molecular targets and evolutionary involvement among genotype, phenotype and subtype-specific tailor-made medicine/prevention of gout and hyperuricaemia.

• Klíčová slova
• Japanese, genome-wide association study (GWAS), gout/hyperuricaemia, selection pressure analysis, subtype specific locus,
• MeSH
• ABC transportér z rodiny G, člen 2 genetika   MeSH
• celogenomová asociační studie * MeSH
• dna (nemoc) epidemiologie   genetika   MeSH
• fenotyp MeSH
• genetická predispozice k nemoci etnologie   MeSH
• genetické lokusy MeSH
• genotyp MeSH
• hodnocení rizik MeSH
• incidence MeSH
• lidé MeSH
• mitochondriální aldehyddehydrogenasa genetika   MeSH
• nádorové proteiny genetika   MeSH
• prognóza MeSH
• referenční hodnoty MeSH
• studie případů a kontrol MeSH
• stupeň závažnosti nemoci MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• metaanalýza MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Japonsko MeSH
• Názvy látek
• ABC transportér z rodiny G, člen 2 MeSH
• ABCG2 protein, human MeSH Prohlížeč
• ALDH2 protein, human MeSH Prohlížeč
• mitochondriální aldehyddehydrogenasa MeSH
• nádorové proteiny MeSH

Disease can act as a driving force in shaping genetic makeup across populations, even species, if the impacts influence a particularly sensitive part of their life cycles. White-nose disease is caused by a fungal pathogen infecting bats during hibernation. The mycosis has caused massive population declines of susceptible species in North America, particularly in the genus Myotis. However, Myotis bats appear to tolerate infection in Eurasia, where the fungal pathogen has co-evolved with its bat hosts for an extended period of time. Therefore, with susceptible and tolerant populations, the fungal disease provides a unique opportunity to tease apart factors contributing to tolerance at a genomic level to and gain an understanding of the evolution of non-harmful in host-parasite interactions. To investigate if the fungal disease has caused adaptation on a genomic level in Eurasian bat species, we adopted both whole-genome sequencing approaches and a literature search to compile a set of 300 genes from which to investigate signals of positive selection in genomes of 11 Eurasian bats at the codon-level. Our results indicate significant positive selection in 38 genes, many of which have a marked role in responses to infection. Our findings suggest that white-nose syndrome may have applied a significant selective pressure on Eurasian Myotis-bats in the past, which can contribute their survival in co-existence with the pathogen. Our findings provide an insight on the selective pressure pathogens afflict on their hosts using methodology that can be adapted to other host-pathogen study systems.

• Klíčová slova
• Adaptation, Bats, Disease, Fungal pathogen, Positive selection, Tolerance,
• MeSH
• Chiroptera * mikrobiologie   genetika   MeSH
• genom MeSH
• genomika metody   MeSH
• interakce hostitele a patogenu genetika   MeSH
• molekulární evoluce MeSH
• mykózy mikrobiologie   veterinární   MeSH
• sekvenování celého genomu MeSH
• selekce (genetika) * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Selective hunting can affect demographic characteristics and phenotypic traits of the targeted species. Hunting systems often involve harvesting quotas based on sex, age and/or size categories to avoid selective pressure. However, it is difficult to assess whether such regulations deter hunters from targeting larger "trophy" animals with longer horns that may have evolutionary consequences. Here, we compile 44,088 annually resolved and absolutely dated measurements of Alpine ibex (Capra ibex) horn growth increments from 8,355 males, harvested between 1978 and 2013, in the eastern Swiss Canton of Grisons. We aim to determine whether male ibex with longer horns were preferentially targeted, causing animals with early rapid horn growth to have shorter lives, and whether such hunting selection translated into long-term trends in horn size over the past four decades. Results show that medium- to longer-horned adult males had a higher probability of being harvested than shorter-horned individuals of the same age and that regulations do affect the hunters' behaviour. Nevertheless, phenotypic traits such as horn length, as well as body size and weight, remained stable over the study period. Although selective trophy hunting still occurs, it did not cause a measurable evolutionary response in Grisons' Alpine ibex populations; managed and surveyed since 1978. Nevertheless, further research is needed to understand whether phenotypic trait development is coinfluenced by other, potentially compensatory factors that may possibly mask the effects of selective, long-term hunting pressure.

• Klíčová slova
• Capra ibex, Alpine ungulate, Swiss Alps, evolutionary change, horn growth, phenotypic plasticity, trophy hunting, wildlife management,
• MeSH
• fenotyp MeSH
• kozy genetika   růst a vývoj   MeSH
• lidské činnosti * MeSH
• rohy růst a vývoj   MeSH
• selekce (genetika) * MeSH
• sporty MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Švýcarsko MeSH

Populations evolve by accumulating advantageous mutations. Every population has some spatial structure that can be modeled by an underlying network. The network then influences the probability that new advantageous mutations fixate. Amplifiers of selection are networks that increase the fixation probability of advantageous mutants, as compared to the unstructured fully-connected network. Whether or not a network is an amplifier depends on the choice of the random process that governs the evolutionary dynamics. Two popular choices are Moran process with Birth-death updating and Moran process with death-Birth updating. Interestingly, while some networks are amplifiers under Birth-death updating and other networks are amplifiers under death-Birth updating, so far no spatial structures have been found that function as an amplifier under both types of updating simultaneously. In this work, we identify networks that act as amplifiers of selection under both versions of the Moran process. The amplifiers are robust, modular, and increase fixation probability for any mutant fitness advantage in a range r ∈ (1, 1.2). To complement this positive result, we also prove that for certain quantities closely related to fixation probability, it is impossible to improve them simultaneously for both versions of the Moran process. Together, our results highlight how the two versions of the Moran process differ and what they have in common.

• MeSH
• biologická evoluce * MeSH
• biologické modely * MeSH
• mutace MeSH
• populační dynamika MeSH
• pravděpodobnost MeSH
• selekce (genetika) MeSH
• Publikační typ
• časopisecké články MeSH

Impressive advances in molecular genetic techniques allow to analyze the effects of natural selection on the development of human genome. For example, the trend towards blonde hair and blue eyes was documented. The approach to analyze possible effects of natural selection on the evolution of recent phenotypes with high risk of cardiovascular disease has not been described yet. A possible effect on the evolution of two main risk factors - hypercholesterolemia and hypertension - is presented. The close relationship of non-HDL cholesterol blood concentration to the proportion of pro-inflammatory macrophages in human visceral adipose tissue might be a result of long-lasting natural selection. Individuals with higher proportion of this phenotype might also display a higher ability to fight infection, which was very common in human setting from prehistory until Middle Ages. Successful battle against infections increased the probability to survive till reproductive age. Similar hypothesis was proposed to explain frequent hypertension in African Americans. A long-lasting selection for higher ability to conserve sodium during long-term adaptation to low sodium intake and hot weather was followed by a short-term (but very hard) natural selection of individuals during transatlantic slave transport. Only those with very high capability to retain sodium were able to survive. Natural selection of phenotypes with high plasma cholesterol concentration and/or high blood pressure is recently potentiated by high-fat high-sodium diet and overnutrition. This hypothesis is also supported by the advantage of familial hypercholesterolemia in the 19th century (at the time of high infection disease mortality) in contrast to the disadvantage of familial hypercholesterolemia during the actual period of high cardiovascular disease mortality.

• MeSH
• genom lidský genetika   MeSH
• kardiovaskulární nemoci epidemiologie   genetika   MeSH
• lidé MeSH
• molekulární evoluce * MeSH
• riziko MeSH
• selekce (genetika) genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Flowering plants show significant diversity in sexual strategies, profoundly impacting the evolution of sexual traits and associated genes. Sexual selection is one of the primary evolutionary forces driving sexual trait variation, particularly evident during pollen-pistil interactions, where pollen grains compete for fertilization and females select mating partners. Multiple mating may intensify competition among pollen donors for siring, while in contrast, self-fertilization reduces sire-sire competition, relaxing the sexual selection pressure. Traits involved in male-male competition and female choice are well described, and molecular mechanisms underlying pollen development and pollen-pistil interactions have been extensively studied in the model species Arabidopsis thaliana. However, whether these molecular mechanisms are involved in sexual selection in nature remains unclear. To address this gap, we measured intrinsic pollen performance and its interaction with female choice and investigated the associated gene expression patterns in a selfing and an outcrossing population of Arabidopsis lyrata. We found that pollen germination and pollen tube growth were significantly higher in outcrossers than selfers, and this difference was accompanied by changes in the expression of genes involved in vesicle transport and cytoskeleton. Outcrosser mother plants showed a negative impact on pollen tube growth compared to selfer mother plants, together with a difference of expression for genes involved in auxin and stress response, suggesting a potential mechanism for female choice through molecular cross talk at the post-pollination stage. Our study provides insight into the impact of sexual selection on the evolution of sexual gene expression in plants.

• Klíčová slova
• Natural variation, Pollen development, Pollen–pistil interactions, Selfing transition, Sexual gene expression, Sexual selection,
• MeSH
• Arabidopsis * genetika   fyziologie   MeSH
• opylení genetika   MeSH
• pohlavní výběr * MeSH
• pyl genetika   fyziologie   růst a vývoj   MeSH
• pylová láčka růst a vývoj   genetika   MeSH
• regulace genové exprese u rostlin MeSH
• samooplození genetika   MeSH
• Publikační typ
• časopisecké články MeSH

Selection of an interspecific hybrid Escherichia coli K12 1EA in a chemostat on xylitol yielded a stable mutant synthesizing a four-fold amount of ribitol dehydrogenase (EC 1.1.1.56). Subsequent cultivation of the mutant under increased selection pressure resulted in an accumulation of a mutant with 12-fold higher level of ribitol dehydrogenase relative to the parent strain 1EA. A selection during which a UV-mutagenized population of the 1EA mutant was cultivated in a chemostat on xylitol was accompanied by monitoring the activities of ribitol dehydrogenase and D-arabinitol dehydrogenase (EC 1.1.1.11) of two adjacent catabolite operons. A several-fold increase in the activity of the two enzymes was followed by further increase in the activity of ribitol dehydrogenase and a concomitant drop in the activity of D-arabinitol dehydrogenase. The two hyperproducing strains are compared with the parent mutant as to the rate of synthesis of the two dehydrogenases and growth parameters under the conditions of batch cultivation.

• MeSH
• bakteriální proteiny biosyntéza   genetika   MeSH
• bakteriologické techniky MeSH
• cukerné alkoholdehydrogenasy biosyntéza   genetika   MeSH
• Escherichia coli enzymologie   genetika   MeSH
• selekce (genetika) MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• cukerné alkoholdehydrogenasy MeSH
• ribitol 2-dehydrogenase MeSH Prohlížeč