Cryptic Dotaz Zobrazit nápovědu
Mutations in SNRP200 gene cause autosomal-dominant retinal disorder retinitis pigmentosa (RP). The protein product of SNRNP200 is BRR2, a DExD/H box RNA helicase crucial for pre-mRNA splicing. In this study, we prepared p.S1087L and p.R1090L mutations of human BRR2 using bacterial artificial chromosome recombineering and stably expressed them in human cell culture. Mutations in BRR2 did not compromise snRNP assembly and both mutants were incorporated into the spliceosome just as the wild-type (wt) protein. Surprisingly, cells expressing RP mutants exhibited increased splicing efficiency of the LDHA gene. Next, we found that depletion of endogenous BRR2 enhanced usage of a β-globin cryptic splice site while splicing at the correct splice site was inhibited. Proper splicing of optimal and cryptic splice sites was restored in cells expressing BRR2-wt but not in cells expressing RP mutants. Taken together, our data suggest that BRR2 is an important factor in 5'-splice-site recognition and that the RP-linked mutations c.3260C>T (p.S1087L) and c.3269G>T (p.R1090L) affect this BRR2 function.
- Klíčová slova
- RNA splicing, SNRP200, U5 snRNP, cryptic splice sites, retinitis pigmentosa,
- MeSH
- alternativní sestřih MeSH
- beta-globiny genetika metabolismus MeSH
- HeLa buňky MeSH
- klonování DNA MeSH
- lidé MeSH
- místa sestřihu RNA genetika MeSH
- mutace * MeSH
- prekurzory RNA genetika metabolismus MeSH
- reportérové geny MeSH
- retinopathia pigmentosa genetika MeSH
- ribonukleoproteiny malé jaderné genetika MeSH
- RNA-helikasy genetika MeSH
- spliceozomy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- beta-globiny MeSH
- místa sestřihu RNA MeSH
- prekurzory RNA MeSH
- ribonukleoproteiny malé jaderné MeSH
- RNA-helikasy MeSH
- SNRNP200 protein, human MeSH Prohlížeč
Naive use of molecular data may lead to ambiguous conclusions, especially within the context of "cryptic" species. Here, we integrated molecular and morphometric data to evaluate phylogenetic relationships in the widespread terrestrial micro-snail genus, Euconulus. We analyzed mitochondrial (16S + COII) and nuclear (ITS1 + ITS2) sequence across 94 populations from Europe, Asia and North America within the nominate species E. alderi, E. fulvus and E. polygyratus, and used the southeastern USA E. chersinus, E. dentatus, and E. trochulus as comparative outgroups. Phylogeny was reconstructed using four different reconstruction methods to identify robust, well-supported topological features. We then performed discriminant analysis on shell measurements between these genetically-identified species-level clades. These analyses provided evidence for a biologically valid North American "cryptic" species within E. alderi. However, while highly supported polyphyletic structure was also observed within E. fulvus, disagreement in placement of individuals between mtDNA and nDNA clades, lack of morphological differences, and presence of potential hybrids imply that these lineages do not rise to the threshold as biologically valid cryptic species, and rather appear to simply represent a complex of geographically structured populations within a single species. These results caution that entering into a cryptic species hypothesis should not be undertaken lightly, and should be optimally supported along multiple lines of evidence. Generally, post-hoc analyses of macro-scale features should be conducted to attempt identification of previously ignored diagnostic traits. If such traits cannot be found, i.e. in the case of potentially "fully cryptic" species, additional criteria should be met to propound a cryptic species hypothesis, including the agreement in tree topology among both mtDNA and nDNA, and little (or no) evidence of hybridization based on a critical analysis of sequence chromatograms. Even when the above conditions are satisfied, it only implies that the cryptic species hypothesis is plausible, but should optimally be subjected to further careful examination.
- Klíčová slova
- Cryptic species, Euconulus, Holarctic range, Micro-land snails, Phylogeny, Shell morphology,
- MeSH
- analýza hlavních komponent MeSH
- buněčné jádro genetika MeSH
- fylogeneze MeSH
- hlemýždi klasifikace genetika MeSH
- pravděpodobnostní funkce MeSH
- respirační komplex IV klasifikace genetika MeSH
- RNA ribozomální 16S klasifikace genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- sekvenční seřazení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- respirační komplex IV MeSH
- RNA ribozomální 16S MeSH
Cryptic invasions are defined as the introduction and spread of non-native lineages within the species' native range (intra-specific cryptic invasion) or the invasion of non-native species that goes unnoticed due to misidentification as a native or another invasive species (inter-specific cryptic invasion). While population-specific attributes are acknowledged to play a critical role in the success and impact of biological invasions in general, our knowledge of the causes and consequences of cryptic invasions is largely neglected. Cryptic invasions are inherently difficult to recognize and, despite being likely widespread, often go undetected. In this review, we analyse the sources, mechanisms, and consequences of cryptic invasions. Using a bibliometric survey, we first quantify the relative proportion of study questions, taxa, and geographic regions. We then highlight the value of comparative information from archived specimens in uncovering the occurrence and timing of cryptic invasions. We examine the mechanisms of cryptic invasions and emphasise the role of anthropogenic environmental changes on the arrival of cryptic invaders. We then discuss the role of interspecific biological interactions in the success of cryptic invasions and the role of hybridization between native and non-native lineages in cryptic invasions. We examine the competitive advantage of some invasive lineages in key physiological, ecological or sexually-selected traits. We argue that cryptic invasions, often undetected, may trigger subsequent rapid range expansions. We suggest that cryptic invasions are much more common than currently acknowledged. We highlight the role of coevolved associations (host-parasite, mutualism, herbivory), inherently population-specific, in the impacts of cryptic invasions on local communities. Finally, we outline a framework to manage intraspecific cryptic invasions.
- Klíčová slova
- Bibliometric, Biological invasions, Conspecific invader, Invasiveness,
- MeSH
- ekologie MeSH
- ekosystém * MeSH
- zavlečené druhy * MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The sympatric occurrence of closely related lineages displaying conserved morphological and ecological traits is often characteristic of free-living microbes. Gene flow, recombination, selection, and mutations govern the genetic variability between these cryptic lineages and drive their differentiation. However, sequencing conservative molecular markers (e.g., 16S rRNA) coupled with insufficient population-level sampling hindered the study of intra-species genetic diversity and speciation in cyanobacteria. We used phylogenomics and a population genomic approach to investigate the extent of local genomic diversity and the mechanisms underlying sympatric speciation of Laspinema thermale. We found two cryptic lineages of Laspinema. The lineages were highly genetically diverse, with recombination occurring more frequently within than between them. That suggests the existence of a barrier to gene flow, which further maintains divergence. Genomic regions of high population differentiation harbored genes associated with possible adaptations to high/low light conditions and stress stimuli, although with a weak diversifying selection. Overall, the diversification of Laspinema species might have been affected by both genomic and ecological processes.
- Klíčová slova
- cryptic species, cyanobacteria, gene flow, phylogenomics, recombination, sympatric speciation,
- Publikační typ
- časopisecké články MeSH
Numerous plant species are expanding their native ranges due to anthropogenic environmental change. Because cytotypes of polyploid complexes often show similar morphologies, there may be unnoticed range expansions (i.e. cryptic invasions) of one cytotype into regions where only the other cytotype is native. We critically revised herbarium specimens of diploid and tetraploid Centaurea stoebe, collected across Europe between 1790 and 2023. Based on their distribution in natural and relict habitats and phylogeographic data, we estimated the native ranges of both cytotypes. Diploids are native across their entire European range, whereas tetraploids are native only to South-Eastern Europe and have recently expanded their range toward Central Europe. The proportion of tetraploids has exponentially increased over time in their expanded but not in their native range. This cryptic invasion predominantly occurred in ruderal habitats and enlarged the climatic niche of tetraploids toward a more oceanic climate. We conclude that spatio-temporally explicit assessments of range shifts, habitat preferences and niche evolution can improve our understanding of cryptic invasions. We also emphasize the value of herbarium specimens for accurate estimation of species´ native ranges, with fundamental implications for the design of research studies and the assessment of biodiversity trends.
- Klíčová slova
- Centaurea stoebe (spotted knapweed), climatic niche, colonization ability, cryptic invasion, herbarium specimens, polyploidy, range expansion, ruderal habitats,
- MeSH
- Centaurea * genetika fyziologie MeSH
- diploidie MeSH
- ekosystém MeSH
- fylogeografie MeSH
- polyploidie * MeSH
- zavlečené druhy * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa MeSH
During surveys of Phytophthora diversity in natural and semi-natural Fagaceae forests in Austria, Italy and Portugal, four new cryptic species were isolated from rhizosphere soil samples. Multigene phylogeny based on nuclear ITS, ß-tubulin and HSP90 and mitochondrial cox1 and NADH1 gene sequences demonstrated that two species, P. tyrrhenica and P. vulcanica spp. nov., belong to phylogenetic Clade 7a, while the other two species, P. castanetorum and P. tubulina spp. nov., clustered together with P. quercina forming a new clade, named here as Clade 12. All four new species are homothallic and have low optimum and maximum temperatures for growth and very slow growth rates at their respective optimum temperature. They differed from each other and from related species by a unique combination of morphological characters, cardinal temperatures, and growth rates. Pathogenicity of all Phytophthora species to the root system of their respective host species was demonstrated in soil infestation trials.
- Klíčová slova
- Clade 7, Phytophthora quercina, cryptic species, evolution, homothallic, phylogeny, species radiation,
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Despite the wealth of studies dealing with the invasions of alien plants, invasions of alien genotypes of native species (cryptic invasions) have been vastly neglected. The impact of cryptic invasions on the biodiversity of plant communities can, however, be significant. Inland saline habitats and halophytes (i.e., salt-tolerant plant species) are especially threatened by this phenomenon as they inhabit fragmented remnants of largely destroyed habitats, but at the same time some of these halophytic species are rapidly spreading along salt-treated roads. To study potential cryptic invasion of halophytes, the patterns of genome size and ploidy variation in the Puccinellia distans complex (Poaceae), the most rapidly spreading roadside halophyte in Central Europe, were investigated. METHODS: DNA flow cytometry with confirmatory chromosome counts were employed to assess ploidy levels of 1414 individuals from 133 populations of the P. distans complex. In addition, climatic niche modelling was used to predict the distributions of selected cytotypes. RESULTS: Eight groups differing in ploidy level and/or genome size were discovered, one diploid (2x; 2n = 14), two tetraploid (4xA, 4xB; 2n = 28), one pentaploid (5x; 2n = 35), three hexaploid (6xA, 6xB, 6xC; 2n = 42), and one heptaploid (7x; 2n = 49). The hexaploids (mostly the 6xC cytotype) were widespread through the study area, spreading intensively in both anthropogenic and natural habitats and probably hybridizing with the natural habitat dwelling tetraploids. In contrast, the non-hexaploid cytotypes rarely spread and were predominantly confined to natural habitats. DISCUSSION: The extensive spread of the hexaploid cytotypes along roadsides has most likely facilitated their incursion into natural habitats. The colonization of new natural habitats by the hexaploids may pose a threat to the indigenous Puccinellia populations by compromising their genetic integrity and/or by outcompeting them.
- Klíčová slova
- Puccinellia distans agg., cryptic invasion, cytogeography, flow cytometry, genetic pollution, halophyte, polyploidy,
- Publikační typ
- časopisecké články MeSH
Cyanobacterial taxonomy is entering the genomic era, but only a few taxonomic studies have employed population genomics, which provides a framework and a multitude of tools to understand species boundaries. Phylogenomic and population genomic analyses previously suggested that several cryptic lineages emerged within the genus Laspinema. Here, we apply population genomics to define boundaries between these lineages and propose two new cryptic species, Laspinema olomoucense and L. palackyanum. Moreover, we sampled soil and puddles across Central Europe and sequenced the 16S rRNA gene and 16S-23S ITS region of the isolated Laspinema strains. Together with database mining of 16S rRNA gene sequences, we determined that the genus Laspinema has a cosmopolitan distribution and inhabits a wide variety of habitats, including freshwater, saline water, mangroves, soil crusts, soils, puddles, and the human body.
- Klíčová slova
- cryptic species, cyanobacteria, evolution, gene flow, new species, phylogenomics, population genomics,
- MeSH
- DNA bakterií genetika MeSH
- fylogeneze * MeSH
- půdní mikrobiologie MeSH
- RNA ribozomální 16S * analýza genetika MeSH
- sekvenční analýza DNA MeSH
- sinice * genetika klasifikace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA bakterií MeSH
- RNA ribozomální 16S * MeSH
We report the distribution of mosquitoes of the maculipennis complex in two distinct areas of the Czech Republic (Bohemia and South Moravia) and in one locality of neighbouring Slovakia with emphasis on the detection of the newly described cryptic species Anopheles daciae (Linton, Nicolescu & Harbach, 2004). A total of 691 mosquitoes were analysed using a species-specific multiplex PCR assay to differentiate between the members of the maculipennis complex. In the Czech Republic, we found Anopheles maculipennis (with a prevalence rate of 1.4%), Anopheles messeae (49.0%) and Anopheles daciae (49.6%). In Slovakia, only An. messeae (52.1%) and An. daciae (47.9%) were detected. In this study, An. daciae was documented for the first time in the two countries where it represented a markedly higher proportion of maculipennis complex species (with an overall prevalence almost reaching 50%) in comparison to previous reports from Germany, Romania and Poland. The determination of the differential distribution of maculipennis complex species will contribute to assessing risks of mosquito-borne diseases such as malaria or dirofilariasis.
- Klíčová slova
- Anopheles daciae, Anophelinae, Cryptic species, Maculipennis complex, Mosquitoes, Vector-borne diseases,
- MeSH
- Anopheles parazitologie MeSH
- Culicidae parazitologie MeSH
- dirofilarióza epidemiologie parazitologie přenos MeSH
- druhová specificita MeSH
- hmyz - vektory parazitologie MeSH
- malárie epidemiologie parazitologie přenos MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika epidemiologie MeSH
- Slovenská republika epidemiologie MeSH
Over time, mountain biota has undergone complex evolutionary histories that have left imprints on its genomic arrangement, geographical distribution and diversity of contemporary lineages. Knowledge on these biogeographical aspects still lags behind for invertebrates inhabiting the Alpine region. In the present study, we examined three scorpion species of the subgenus Euscorpius (Alpiscorpius) from the European Alps using cytogenetic and molecular phylogenetic approaches to determine the variation and population structure of extant lineages at both chromosome and genetic level, and to provide an insight into the species diversification histories. We detected considerable intraspecific variability in chromosome complements and localization of the 18S rDNA loci in all studied species. Such chromosome differences were noticeable as the existence of three [in E. (A.) alpha and E. (A.) germanus] or four [in E. (A.) gamma] range-restricted karyotypic races. These races differed from one another either by 2n [in E. (A.) alpha 2n = 54, 60, 90; in E. (A.) gamma 2n = 58, 60, 88, 86-92], or by the karyotypic formula [in E. (A.) germanus 2n = 34m + 12sm; 36m + 10sm; 42m + 4sm]. Using mitochondrial (16S rRNA, COI) and nuclear (28S rDNA) genetic markers, we examined genetic variation and reconstructed phylogenetic relationships among the karyotypic races. Both approaches provided evidence for the existence of ten deeply divergent lineages exhibiting the features of local endemics and indicating the presence of cryptic species. Molecular dating analyses suggest that these lineages diversified during the Plio-Pleistocene and this process was presumably accompanied by dynamic structural changes in the genome organization.
- Klíčová slova
- Alps, Cryptic species, Evolution, Karyotype evolution, Phylogeography, Species delimitation,
- MeSH
- alely MeSH
- časové faktory MeSH
- chromozomy genetika MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- genom MeSH
- karyotypizace MeSH
- molekulární evoluce * MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- štíři genetika MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ribozomální DNA MeSH
- RNA ribozomální 16S MeSH