Jandzik, David*
Dotaz
Zobrazit nápovědu
The last two populations of the Hungarian meadow viper Vipera ursinii rakosiensis were thought to persist in the steppe fragments of Hungary until meadow vipers were discovered in central Romania (Transylvania), suggesting a possible existence of remnant populations elsewhere. We assessed the phylogenetic position of the Transylvanian vipers using 2030 bp of mitochondrial DNA sequence. We showed that they were closely related to the Hungarian vipers, while those from northeastern Romania (Moldavia) and Danube Delta belonged to the subspecies Vipera ursinii moldavica. Montane subspecies from Europe (Vipera ursinii ursinii and Vipera ursinii macrops) formed a sister clade to the two lowland subspecies. Vipera renardi formed a sister clade to V. ursinii, with populations from the Greater Caucasus (Vipera renardi lotievi) and Tien Shan (Vipera renardi tienshanica) as the sister group to Vipera renardi renardi, and Vipera renardi eriwanensis from the Lesser Caucasus as the most basal taxon in the species. Our results illustrate that the divergence between the lowland and montane populations occurred separately in each species and several times in V. renardi. We demonstrated that the recently discovered Transylvanian population is the third surviving population of V. u. rakosiensis and the only known population outside of Hungary.
The apparent evolvability of the vertebrate head skeleton has allowed a diverse array of shapes, sizes, and compositions of the head in order to better adapt species to their environments. This encompasses feeding, breathing, sensing, and communicating: the head skeleton somehow participated in the evolution of all these critical processes for the last 500 million years. Through evolution, present head diversity was made possible via developmental modifications to the first head skeletal genetic program. Understanding the development of the vertebrate common ancestor's head skeleton is thus an important step in identifying how different lineages have respectively achieved their many innovations in the head. To this end, cyclostomes (jawless vertebrates) are extremely useful, having diverged from jawed vertebrates approximately 400 million years ago, at the deepest node within living vertebrates. From this ancestral vantage point (that is, the node connecting cyclostomes and gnathostomes) we can best identify the earliest major differences in development between vertebrate classes, and start to address how these might translate onto morphology. In this review we survey what is currently known about the cell biology and gene expression during head development in modern vertebrates, allowing us to better characterize the developmental genetics driving head skeleton formation in the most recent common ancestor of all living vertebrates. By pairing this vertebrate composite with information from fossil chordates, we can also deduce how gene regulatory modules might have been arranged in the ancestral vertebrate head. Together, we can immediately begin to understand which aspects of head skeletal development are the most conserved, and which are divergent, informing us as to when the first differences appear during development, and thus which pathways or cell types might be involved in generating lineage specific shape and structure.
- MeSH
- biologická evoluce * MeSH
- genetická variace * MeSH
- hlava růst a vývoj MeSH
- lebka růst a vývoj MeSH
- obratlovci genetika růst a vývoj MeSH
- zkameněliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The maternal origin of isolated populations of the common wall lizard (Podracis muralis) in the Czech Republic, representing the north-eastern range border of the species, was addressed. We compared mitochondrial DNA sequences of the cytochrome b gene of samples from these populations with those from within the continuous range in Slovakia, the northern Balkan region, and those available from previous studies. We recorded five main haplogroups in the studied region, with all available Central European samples belonging to the same haplogroup. The star-like structure of this haplogroup suggests a scenario of relatively recent, post-glacial population expansion, which is further supported by a coalescent-based demographic analysis. The presence of unique haplotypes in two of the three isolated Czech populations together with close phylogenetic relationships to adjacent Slovak populations suggests either autochthonous origin or human-mediated introductions from geographically and genetically closest populations. We therefore support conservation programs for all three isolated Czech populations.
- MeSH
- cytochromy b genetika MeSH
- genetická variace * MeSH
- haplotypy MeSH
- ještěři klasifikace genetika MeSH
- mitochondriální DNA genetika MeSH
- populační růst MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
It is the first time that Crimean-Congo haemorrhagic fever virus (CCHFV), causing potentially lethal disease of humans, has been reported from the Middle East region and from the tortoise tick Hyalomma aegyptium from a tortoise host, whose epidemiological significance may have remained almost completely overlooked so far. We used RT-PCR to screen for 245 ticks collected from 38 Testudo graeca tortoise individuals. Results of our genetic screening provide unambiguous evidence of occurrence of CCHFV in this region and host, suggesting a potentially important role of H. aegyptium in CCHF epidemiology.
- MeSH
- fylogeneze MeSH
- haplotypy MeSH
- infestace klíšťaty epidemiologie mikrobiologie veterinární MeSH
- klíšťata virologie MeSH
- virus krymsko-konžské hemoragické horečky genetika izolace a purifikace MeSH
- želvy parazitologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Sýrie MeSH
- Turecko MeSH
Four species of legless anguid lizard genus Anguis have been currently recognized: A. fragilis from western and central Europe, A. colchica from eastern Europe and western Asia, A. graeca from southern Balkans, and A. cephallonica from the Peloponnese. Slow worms from the Italian Peninsula have been considered conspecific with A. fragilis, despite the fact that the region served as an important speciation center for European flora and fauna, and included some Pleistocene glacial refugia. We used mitochondrial and nuclear DNA sequences to investigate the systematic and phylogenetic position of the Italian slow-worm populations and morphological analyses to test for phenotypic differentiation from A. fragilis from other parts of Europe. Our phylogenetic analyses revealed that Italian slow worms form a distinct deeply differentiated mtDNA clade, which presumably diverged during or shortly after the basal radiation within the genus Anguis. In addition, the specimens assigned to this clade bear distinct haplotypes in nuclear PRLR gene and show morphological differentiation from A. fragilis. Based on the differentiation in all three independent markers, we propose to assign the Italian clade species level under the name Anguis veronensisPollini, 1818. The newly recognized species is distributed throughout the Italian Peninsula to the Southern Alps and south-eastern France. We hypothesize that the Tertiary Alpine orogeny with subsequent vicariance might have played a role in differentiation of this species. The current genetic variability was later presumably shaped in multiple glacial refugia within the Italian Peninsula, with the first splitting event separating populations from the region of the Dolomite Mountains.
- MeSH
- Bayesova věta MeSH
- biologická evoluce * MeSH
- buněčné jádro genetika MeSH
- fylogeneze * MeSH
- genetická variace MeSH
- haplotypy MeSH
- ještěři anatomie a histologie klasifikace genetika MeSH
- mitochondriální DNA genetika MeSH
- pravděpodobnostní funkce MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Itálie MeSH
The generic name Hemolivia has been used for haemogregarines characterized by morphological and biological features. The few molecular studies, focused on other haemogregarine genera but involving Hemolivia samples, indicated its close relationship to the genus Hepatozoon. Here we analyze molecular data for Hemolivia from a broad geographic area and host spectrum and provide detailed morphological documentation of the included samples. Based on molecular analyses in context of other haemogregarines, we demonstrate that several sequences deposited in GenBank from isolates described as Hepatozoon belong to the Hemolivia cluster. This illustrates the overall difficulty with recognizing Hemolivia and Hepatozoon without sufficient morphological and molecular information. The close proximity of both genera is also reflected in uncertainty about their precise phylogeny when using 18S rDNA. They cluster with almost identical likelihood either as two sister taxa or as monophyletic Hemolivia within paraphyletic Hepatozoon. However, regardless of these difficulties, the results presented here provide a reliable background for the unequivocal placement of new samples into the Hemolivia/ Hepatozoon complex.
- MeSH
- Coccidia klasifikace cytologie genetika izolace a purifikace MeSH
- fylogeneze MeSH
- mikroskopie MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA chemie genetika MeSH
- ribozomální DNA chemie genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- shluková analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In most vertebrates, pharyngeal arches form in a stereotypic anterior-to-posterior progression. To gain insight into the mechanisms underlying evolutionary changes in pharyngeal arch development, here we investigate embryos and larvae of bichirs. Bichirs represent the earliest diverged living group of ray-finned fishes, and possess intriguing traits otherwise typical for lobe-finned fishes such as ventral paired lungs and larval external gills. In bichir embryos, we find that the anteroposterior way of formation of cranial segments is modified by the unique acceleration of the entire hyoid arch segment, with earlier and orchestrated development of the endodermal, mesodermal, and neural crest tissues. This major heterochronic shift in the anteroposterior developmental sequence enables early appearance of the external gills that represent key breathing organs of bichir free-living embryos and early larvae. Bichirs thus stay as unique models for understanding developmental mechanisms facilitating increased breathing capacity.
BACKGROUND: Genetic architecture of a species is a result of historical changes in population size and extent of distribution related to climatic and environmental factors and contemporary processes of dispersal and gene flow. Population-size and range contractions, expansions and shifts have a substantial effect on genetic diversity and intraspecific divergence, which is further shaped by gene-flow limiting barriers. The Balkans, as one of the most important sources of European biodiversity, is a region where many temperate species persisted during the Pleistocene glaciations and where high topographic heterogeneity offers suitable conditions for local adaptations of populations. In this study, we investigated the phylogeographical patterns and demographic histories of four species of semifossorial slow-worm lizards (genus Anguis) present in the Balkan Peninsula, and tested the relationship between genetic diversity and topographic heterogeneity of the inhabited ranges. RESULTS: We inferred phylogenetic relationships, compared genetic structure and historical demography of slow worms using nucleotide sequence variation of mitochondrial DNA. Four Anguis species with mostly parapatric distributions occur in the Balkan Peninsula. They show different levels of genetic diversity. A signature of population growth was detected in all four species but with various courses in particular populations. We found a strong correlation between genetic diversity of slow-worm populations and topographic ruggedness of the ranges (mountain systems) they inhabit. Areas with more rugged terrain harbour higher genetic diversity. CONCLUSIONS: Phylogeographical pattern of the genus Anguis in the Balkans is concordant with the refugia-within-refugia model previously proposed for both several other taxa in the region and other main European Peninsulas. While slow-worm populations from the southern refugia mostly have restricted distributions and have not dispersed much from their refugial areas, populations from the extra-Mediterranean refugia in northern parts of the Balkans have colonized vast areas of eastern, central, and western Europe. Besides climatic historical events, the heterogeneous topography of the Balkans has also played an important role in shaping genetic diversity of slow worms.
- MeSH
- biodiverzita MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- ještěři genetika MeSH
- mitochondriální DNA genetika MeSH
- molekulární evoluce MeSH
- polymorfismus genetický MeSH
- tok genů MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Balkánský poloostrov MeSH
Ticks are important vectors of various microorganisms, including bacteria. In this study, we examined Hyalomma aegyptium ticks collected from 240 spur-thighed tortoises Testudo graeca at 42 localities in the Mediterranean and Middle East and analysed them for the presence of bacteria of the genera Anaplasma, Borrelia, Coxiella, and Rickettsia. Altogether, 576 out of 928 analysed ticks (62.1%) were positive for at least one of the tested bacteria. The highest prevalence in individual ticks was found for Borrelia turcica (43.6%), followed by Rickettsia (12.3%) and Anaplasma (6.1%). No sample was positive for Coxiella burnetii. Among Rickettsia, we detected two species, Rickettsia africae and Rickettsia aeschlimannii, and also other unspecified Rickettsia. Anaplasma (100% identity with A. phagocytophilum) was detected at 15 (35%) out of 42 studied localities, any of Rickettsia at 28 (67%), and B. turcica at 32 (76%) localities. The geographic distribution of the studied microorganisms varied, with none of them detected in Syria, and only Rickettsia spp. detected in Morocco. Sequence analysis revealed substantial genetic variability in all detected agents, with the most variable (36 new haplotypes) being glpQ gene used as a marker for B. turcica. We also analysed the prevalence of various co-infections among studied ticks, with the mean number of co-infected ticks per tortoise increased with the number of ticks per tortoise. However, the frequencies of co-infected ticks do not indicate the presence of antagonistic or synergistic facilitative interactions between the agents. According to our data, we could expect that the eco-epidemiological importance of H. aegyptium does not stem from their tortoise hosts but rather from the low host specificity of its larvae and nymphs, feeding on a wider spectrum of reptilian, avian, and mammalian hosts.
- MeSH
- Anaplasma * izolace a purifikace MeSH
- Borrelia izolace a purifikace MeSH
- Coxiella izolace a purifikace genetika MeSH
- infestace klíšťaty veterinární epidemiologie parazitologie MeSH
- Ixodidae * mikrobiologie růst a vývoj MeSH
- Rickettsia * izolace a purifikace MeSH
- želvy * mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Střední východ MeSH
- Středomoří MeSH
Kotschy's Gecko, Mediodactylus kotschyi, is a small gecko native to southeastern Europe and the Levant. It displays great morphological variation with a large number of morphologically recognized subspecies. However, it has been suggested that it constitutes a species complex of several yet unrecognized species. In this study, we used multilocus sequence data (three mitochondrial and three nuclear gene fragments) to estimate the phylogenetic relationships of 174 specimens from 129 sampling localities, covering a substantial part of the distribution range of the species. Our results revealed high genetic diversity of M. kotschyi populations and contributed to our knowledge about the phylogenetic relationships and the estimation of the divergence times between them. Diversification within M. kotschyi began approximately 15 million years ago (Mya) in the Middle Miocene, whereas the diversification within most of the major clades have been occurred in the last 5 Mya. Species delimitation analysis suggests there exists five species within the complex, and we propose to tentatively recognize the following taxa as full species: M. kotschyi (mainland Balkans, most of Aegean islands, and Italy), M. orientalis (Levant, Cyprus, southern Anatolia, and south-eastern Aegean islands), M. danilewskii (Black Sea region and south-western Anatolia), M. bartoni (Crete), and M. oertzeni (southern Dodecanese Islands). This newly recognized diversity underlines the complex biogeographical history of the Eastern Mediterranean region.
- MeSH
- Bayesova věta MeSH
- časové faktory MeSH
- druhová specificita MeSH
- fylogeneze * MeSH
- genetická variace * MeSH
- genetické lokusy * MeSH
- ještěři klasifikace genetika MeSH
- mitochondriální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční seřazení MeSH
- zeměpis MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
