Parallel adaptive radiations have arisen following the colonization of islands by lizards and lakes by fishes. In these classic examples, parallel adaptive radiation is a response to the ecological opportunities afforded by the colonization of novel ecosystems and similar adaptive landscapes that favour the evolution of similar suites of ecomorphs, despite independent evolutionary histories. Here, we demonstrate that parallel adaptive radiations of cichlid fishes arose in South American rivers. Speciation-assembled communities of pike cichlids (Crenicichla) have independently diversified into similar suites of novel ecomorphs in the Uruguay and Paraná Rivers, including crevice feeders, periphyton grazers and molluscivores. There were bursts in phenotypic evolution associated with the colonization of each river and the subsequent expansion of morphospace following the evolution of the ecomorphs. These riverine clades demonstrate that characteristics emblematic of textbook parallel adaptive radiations of island- and lake-dwelling assemblages are feasible evolutionary outcomes even in labile ecosystems such as rivers.
- MeSH
- Adaptation, Biological genetics MeSH
- Biological Evolution * MeSH
- Cichlids anatomy & histology genetics MeSH
- Ecosystem MeSH
- Phenotype MeSH
- Phylogeny MeSH
- Polymorphism, Single Nucleotide genetics MeSH
- Lakes MeSH
- Islands MeSH
- Rivers * MeSH
- Whole Genome Sequencing MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Geographicals
- Islands MeSH
- Uruguay MeSH
BACKGROUND: Darwin's evolutionary theory could easily explain the evolution of adaptive traits (organs and behavioral patterns) in asexual but not in sexual organisms. Two models, the selfish gene theory and frozen plasticity theory were suggested to explain evolution of adaptive traits in sexual organisms in past 30 years. RESULTS: The frozen plasticity theory suggests that sexual species can evolve new adaptations only when their members are genetically uniform, i.e. only after a portion of the population of the original species had split off, balanced on the edge of extinction for several generations, and then undergone rapid expansion. After a short period of time, estimated on the basis of paleontological data to correspond to 1-2% of the duration of the species, polymorphism accumulates in the gene pool due to frequency-dependent selection; and thus, in each generation, new mutations occur in the presence of different alleles and therefore change their selection coefficients from generation to generation. The species ceases to behave in an evolutionarily plastic manner and becomes evolutionarily elastic on a microevolutionary time-scale and evolutionarily frozen on a macroevolutionary time-scale. It then exists in this state until such changes accumulate in the environment that the species becomes extinct. CONCLUSION: Frozen plasticity theory, which includes the Darwinian model of evolution as a special case--the evolution of species in a plastic state, not only offers plenty of new predictions to be tested, but also provides explanations for a much broader spectrum of known biological phenomena than classic evolutionary theories. REVIEWERS: This article was reviewed by Rob Knight, Fyodor Kondrashov and Massimo Di Giulio (nominated by David H. Ardell).
BACKGROUND: DNA methylation plays a key role in development, contributes to genome stability, and may also respond to external factors supporting adaptation and evolution. To connect different types of stimuli with particular biological processes, identifying genome regions with altered 5-methylcytosine distribution at a genome-wide scale is important. Many researchers are using the simple, reliable, and relatively inexpensive Methylation Sensitive Amplified Polymorphism (MSAP) method that is particularly useful in studies of epigenetic variation. However, electrophoretic patterns produced by the method are rather difficult to interpret, particularly when MspI and HpaII isoschizomers are used because these enzymes are methylation-sensitive, and any C within the CCGG recognition motif can be methylated in plant DNA. RESULTS: Here, we evaluate MSAP patterns with respect to current knowledge of the enzyme activities and the level and distribution of 5-methylcytosine in plant and vertebrate genomes. We discuss potential caveats related to complex MSAP patterns and provide clues regarding how to interpret them. We further show that addition of combined HpaII + MspI digestion would assist in the interpretation of the most controversial MSAP pattern represented by the signal in the HpaII but not in the MspI profile. CONCLUSIONS: We recommend modification of the MSAP protocol that definitely discerns between putative hemimethylated mCCGG and internal CmCGG sites. We believe that our view and the simple improvement will assist in correct MSAP data interpretation.
- MeSH
- 5-Methylcytosine chemistry MeSH
- DNA, Plant genetics MeSH
- Epigenesis, Genetic MeSH
- DNA Methylation * MeSH
- Vertebrates genetics MeSH
- Polymorphism, Genetic * MeSH
- Restriction Mapping MeSH
- Nicotiana genetics MeSH
- Nucleic Acid Amplification Techniques methods MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Adaptive gene flow is a consequential phenomenon across all kingdoms. Although recognition is increasing, there is no study showing that bidirectional gene flow mediates adaptation at loci that manage core processes. We previously discovered concerted molecular changes among interacting members of the meiotic machinery controlling crossover number upon adaptation to whole-genome duplication (WGD) in Arabidopsis arenosa. Here we conduct a population genomic study to test the hypothesis that adaptation to WGD has been mediated by adaptive gene flow between A. arenosa and A. lyrata. We find that A. lyrata underwent WGD more recently than A. arenosa, suggesting that pre-adapted alleles have rescued nascent A. lyrata, but we also detect gene flow in the opposite direction at functionally interacting loci under the most extreme levels of selection. These data indicate that bidirectional gene flow allowed for survival after WGD, and that the merger of these species is greater than the sum of their parts.
Speciation mechanisms remain controversial. Two speciation models occur in Israeli subterranean mole rats, genus Spalax: a regional speciation cline southward of four peripatric climatic chromosomal species and a local, geologic-edaphic, genic, and sympatric speciation. Here we highlight their genome evolution. The five species were separated into five genetic clusters by single nucleotide polymorphisms, copy number variations (CNVs), repeatome, and methylome in sympatry. The regional interspecific divergence correspond to Pleistocene climatic cycles. Climate warmings caused chromosomal speciation. Triple effective population size, Ne , declines match glacial cold cycles. Adaptive genes evolved under positive selection to underground stresses and to divergent climates, involving interspecies reproductive isolation. Genomic islands evolved mainly due to adaptive evolution involving ancient polymorphisms. Repeatome, including both CNV and LINE1 repetitive elements, separated the five species. Methylation in sympatry identified geologically chalk-basalt species that differentially affect thermoregulation, hypoxia, DNA repair, P53, and other pathways. Genome adaptive evolution highlights climatic and geologic-edaphic stress evolution and the two speciation models, peripatric and sympatric.
- MeSH
- Adaptation, Biological MeSH
- Biological Evolution * MeSH
- Epigenesis, Genetic MeSH
- Genetic Variation MeSH
- Genome MeSH
- Polymorphism, Single Nucleotide MeSH
- Evolution, Molecular MeSH
- Genetics, Population MeSH
- Reproductive Isolation MeSH
- Spalax genetics physiology MeSH
- Sympatry * MeSH
- Gene Flow MeSH
- DNA Copy Number Variations MeSH
- Linkage Disequilibrium MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Israel MeSH
The columbine genus Aquilegia is a classic example of an adaptive radiation, involving a wide variety of pollinators and habitats. Here we present the genome assembly of A. coerulea 'Goldsmith', complemented by high-coverage sequencing data from 10 wild species covering the world-wide distribution. Our analyses reveal extensive allele sharing among species and demonstrate that introgression and selection played a role in the Aquilegia radiation. We also present the remarkable discovery that the evolutionary history of an entire chromosome differs from that of the rest of the genome - a phenomenon that we do not fully understand, but which highlights the need to consider chromosomes in an evolutionary context.
- MeSH
- Aquilegia genetics MeSH
- Adaptation, Biological * MeSH
- Chromosomes, Plant * MeSH
- Plant Dispersal MeSH
- Genome, Plant * MeSH
- Evolution, Molecular * MeSH
- Sequence Analysis, DNA MeSH
- Selection, Genetic MeSH
- Gene Flow MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Pertuse je významnou příčinou nemocnosti a úmrtnosti u dětí. Acelulární vakcíny jsou považovány za bezpečné, ale přibývá důkazů, že acelulární vakcíny nejsou schopny onemocnění pertusí dostatečně kontrolovat. Je třeba stávající vakcíny zlepšit nebo vyvinout nové, účinnější vakcíny.
Pertussis is a significant cause of chilhood morbidity and mortality. Acellular pertussis vaccines are considered safer but there is growing evidence that the acellular vaccines are unable to optimal control of pertussis disease. It is necessary to improve current vaccines and to develop new, more effective vaccines.
- Keywords
- celobuněčná vakcína, vyvanutí imunity, pertactin,
- MeSH
- Vaccines, Acellular immunology MeSH
- Adaptive Immunity immunology MeSH
- Antigens, Bacterial immunology MeSH
- Vaccines, Attenuated immunology MeSH
- Bordetella pertussis * genetics immunology pathogenicity MeSH
- DNA, Bacterial genetics MeSH
- Virulence Factors, Bordetella genetics immunology MeSH
- Humans MeSH
- Evolution, Molecular MeSH
- Whooping Cough * immunology prevention & control MeSH
- Pertussis Vaccine * immunology MeSH
- Pertussis Toxin immunology MeSH
- Polymorphism, Genetic MeSH
- Bacterial Outer Membrane Proteins genetics immunology MeSH
- Vaccination MeSH
- Check Tag
- Humans MeSH
- Publication type
- Review MeSH
Immunity exhibits extraordinarily high levels of variation. Evolution of the immune system in response to host-pathogen interactions in particular ecological contexts appears to be frequently associated with diversifying selection increasing the genetic variability. Many studies have documented that immunologically relevant polymorphism observed today may be tens of millions years old and may predate the emergence of present species. This pattern can be explained by the concept of trans-species polymorphism (TSP) predicting the maintenance and sharing of favourable functionally important alleles of immune-related genes between species due to ongoing balancing selection. Despite the generality of this concept explaining the long-lasting adaptive variation inherited from ancestors, current research in TSP has vastly focused only on major histocompatibility complex (MHC). In this review we summarise the evidence available on TSP in human and animal immune genes to reveal that TSP is not a MHC-specific evolutionary pattern. Further research should clearly pay more attention to the investigation of TSP in innate immune genes and especially pattern recognition receptors which are promising candidates for this type of evolution. More effort should also be made to distinguish TSP from convergent evolution and adaptive introgression. Identification of balanced TSP variants may represent an accurate approach in evolutionary medicine to recognise disease-resistance alleles.
- MeSH
- Alleles MeSH
- Major Histocompatibility Complex genetics immunology MeSH
- Host-Pathogen Interactions genetics immunology MeSH
- Humans MeSH
- Evolution, Molecular MeSH
- Polymorphism, Genetic genetics immunology MeSH
- Immunity, Innate genetics immunology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Cílem studie bylo hodnotit asociaci polymorfismu A1166C v genu pro AT 1 receptor pro angiotenzin II (AT 1 R) s citlivostí baroreflexu (BRS) a polymorfismů T-786C a G894T v genu pro endoteliální syntázu oxidu dusnatého (eNOS) s variabilitou v krevním tlaku (VTK) u mladých netrénovaných lidí a upozornit tak na možná rizika vzniku kardiovaskulárních onemocnění u sportovců. U 152 zdravých osob byly opakovaně registrovány fluktuace systolického a diastolického tlaku a srdeční frekvence Peňázovou metodou. Genotypy byly detekovány metodou PCR a RFLP. Byla nalezena signifikantní asociace polymorfismu A1166C v genu pro AT 1 R s BRS a polymorfismů T-786C a G894T v genu pro eNOS s VTK.
The aim of the study was to evaluate the association of polymorphism A1166C in gene encoding angiotensin II receptor (AT 1 R) with baroreflex sensitivity (RRS) and polymorphisms T-786C and G894T in gene encoding endothelial nitric oxide synthase (eNOS) with blood pressure variability (BPV) in young untrained subjects and point at possible risk factors for development of cardiovascular diseases in sportsmen. The fluctuations in systolic and diastolic blood pressure and heart rate were repeatedly registered by method by Peňáz. The genotypes were detected by PCR and RFLP. A significant association of polymorphism A1166C in gene encoding AT 1 R with BRS and of polymorphisms T-786C a G894T in gene encoding eNOS with BPV was found.
