lizard
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BACKGROUND: Despite the fact that numerous reptile species are widely studied by the researchers, information describing the detailed structure of particular organs in many reptiles is missing. MATERIALS AND METHODS: The tongue of the sand lizard (Lacerta agilis) was examined under the light and scanning electron microscope. It is divided into bifurcated apex, corpus and bifurcated radix. The tip of the lingual apex is devoid of lingual papillae. RESULTS: The remaining dorsal surface of the tongue bears either fused papillae in the form of caudally directed ridges or individual papillae represented by mu- shroom-like or semilunar prominences (lingual apex) or fish scale-like papillae (lingual corpus) and horizontally laid ridges extending in the form of lobulated prominences (lingual corpus, lingual radix). Regardless of the shape, lingual papillae contain numerous muscle fibres and they are all considered to be mechanical. The lingual epithelium changes from the simple squamous into stratified squamous in the caudal direction. No salivary glands or sensory structures were recognised. CONCLUSIONS: This description is to be used mainly for comparative studies. It could also help to understand how different lizards capture the pray.
- MeSH
- jazyk ultrastruktura MeSH
- ještěři anatomie a histologie MeSH
- mikroskopie elektronová rastrovací MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Four out of twenty (20%) specimens of the lizard Scincus hemprichii Wiegmann, collected in Saudi Arabia were infected with a previously undescribed species of Choleoeimeria. Oocysts of Choleoeimeria jazanensis sp. n. are cylindroidal, 26 x 15 microm, with a smooth bilayered wall and a shape index of 1.7. Oocyst residuum and micropyle are absent. Sporocysts are subspherical, 10 x 7 microm, with a shape index of 1.3. The Stieda body is absent. Sporozoites are banana-shaped, 10 x 3 microm, with one refractile body and enclosed the fine granulated sporocyst residuum. The endogenous development is confined to the gall bladder epithelium, with infected cells being displaced from the epithelium layer towards lumen. Mature meronts are subspherical and estimates to produce 9-12 merozoites. Microgamonts are spherical in shape with diameter of 13 microm. Macrogamonts are subspherical with a prominent nucleus in centre and wall-forming bodies at periphery.
- MeSH
- Eimeriidae klasifikace cytologie izolace a purifikace MeSH
- ještěři parazitologie MeSH
- kokcidióza epidemiologie parazitologie veterinární MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Saudská Arábie MeSH
Reptiles use pterin and carotenoid pigments to produce yellow, orange, and red colors. These conspicuous colors serve a diversity of signaling functions, but their molecular basis remains unresolved. Here, we show that the genomes of sympatric color morphs of the European common wall lizard (Podarcis muralis), which differ in orange and yellow pigmentation and in their ecology and behavior, are virtually undifferentiated. Genetic differences are restricted to two small regulatory regions near genes associated with pterin [sepiapterin reductase (SPR)] and carotenoid [beta-carotene oxygenase 2 (BCO2)] metabolism, demonstrating that a core gene in the housekeeping pathway of pterin biosynthesis has been coopted for bright coloration in reptiles and indicating that these loci exert pleiotropic effects on other aspects of physiology. Pigmentation differences are explained by extremely divergent alleles, and haplotype analysis revealed abundant transspecific allele sharing with other lacertids exhibiting color polymorphisms. The evolution of these conspicuous color ornaments is the result of ancient genetic variation and cross-species hybridization.
- MeSH
- alkoholoxidoreduktasy genetika fyziologie MeSH
- barva MeSH
- dioxygenasy genetika MeSH
- ještěři genetika metabolismus MeSH
- karotenoidy genetika metabolismus MeSH
- pigmentace kůže genetika MeSH
- pigmentace genetika MeSH
- polymorfismus genetický genetika MeSH
- pteriny metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Apicomplexan haemoparasites of the genera Schellackia Reichenow, 1919, and Karyolysus Labbé, 1894, seem to be common in lizards and widespread across the world. For decades, their identification has been based on morphological descriptions and life cycle patterns, with molecular characterizations, applied only recently. We used molecular characterization to confirm the identification of haemoparasites detected by microscopy in blood smears of Lacerta schreiberi Bedriaga, 1878, a lizard of the Iberian Peninsula. Since blood samples other than blood smears were not available from the studied lizards, 264 engorged ticks Ixodes ricinus (Linneaus, 1758) collected from them were used as an alternative non-invasive source of haemoparasite DNA for molecular genetic analyses. Of the 48 blood smears microscopically examined, 31 were positive for blood parasites (64.6% prevalence). We identified trophozoites and gamonts similar to Karyolysus lacazei (Labbé, 1894) (24/48; 50%) and Schellackia-like sporozoites (20/48; 41.7%). Mixed infections with both species occurred in 13 blood smears (27.1%). Sequence data were obtained for both parasites from engorged ticks. Phylogenetic analyses placed our unique haemogregarine sequence within the Karyolysus clade, nevertheless, within substantial polytomy. Thus, according to its morphology and effect on the host cell, we refer to this haemogregarine as Karyolysus cf. lacazei. Besides the Schellackia sequences being identical to a previously identified haplotype, we also obtained sequences of three new closely related haplotypes.
- MeSH
- Eucoccidiida klasifikace MeSH
- fylogeneze MeSH
- genetická variace * MeSH
- haplotypy MeSH
- ještěři parazitologie MeSH
- klíště parazitologie MeSH
- kokcidióza krev parazitologie veterinární MeSH
- protozoální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- sporozoiti genetika MeSH
- trofozoiti genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem 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
Spotted fever rickettsioses are tick-borne diseases of growing public health concern. The prevalence of rickettsia-infected ticks and their ability to parasitize humans significantly influence the risk of human infection. Altogether 466 Ixodes ricinus ticks (428 nymphs and 38 larvae) collected from 73 Lacerta schreiberi lizards were examined by PCR targeting the citrate synthetase gene gltA for the presence of Rickettsia spp. Rickettsial DNA was detected in 47% of nymphs and 31.6% of larvae. They were subsequently subjected to a second PCR reaction using primers derived from the outer membrane protein rOmpA encoding gene (ompA) to detect spotted fever group rickettsiae (SFG). This analysis shows that 41.4% of nymphs and 7.9% of larvae collected from the lizards contain DNA of SFG rickettsiae. Sequencing of 43 randomly selected samples revealed two different haplotypes, both closely related to R. monacensis (39 and 4 samples, respectively). The remaining ompA negative Rickettsia spp. samples were determined to be R. helvetica based on sequencing of ompB and gltA fragments. Our results indicate that the role of Iberian endemic lizard L. schreiberi and its ectoparasites in the ecology and epidemiology of zoonotic SFG rickettsioses may be appreciable.
- MeSH
- DNA bakterií genetika izolace a purifikace MeSH
- fylogeneze MeSH
- infestace klíšťaty parazitologie veterinární MeSH
- ještěři parazitologie MeSH
- klíště mikrobiologie MeSH
- larva mikrobiologie MeSH
- nymfa mikrobiologie MeSH
- proteiny vnější bakteriální membrány genetika metabolismus MeSH
- regulace genové exprese u bakterií fyziologie MeSH
- Rickettsia klasifikace izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Variable clutch size is unambiguously an ancestral state in reptiles. Only several lizard lineages have evolved so-called invariant clutch size, where all females lay just one or two eggs per clutch. This mode of reproduction is characteristic for geckos. In some gecko lineages, decreased fecundity in a single clutch is compensated by conspicuous shortening of interclutch intervals. The proximate mechanism of high clutch frequency in these geckos is not known. Here, we document that three subsequently laid clutches develop simultaneously in females of the Madagascar ground gecko (Paroedura picta). The extremely short interclutch intervals in this species-even as short as a week-thus could be attributed to the overlap of female reproductive cycles. Such overlap should be associated with altered female hormonal cycles. Based on measurements of hormonal levels, we suggest that cycles of estradiol and progesterone during reproductive cycles of females in P. picta are largely independent. Thus, in contrast to the presumable ancestral reptile state, higher levels of progesterone do not seem to interfere with vitellogenesis in this species. We discuss potential consequences of this derived mode of reproduction, such as possible simultaneous maternal transfer of nutrients and other yolk components to several subsequent clutches.
- MeSH
- časové faktory MeSH
- estradiol krev MeSH
- ještěři fyziologie MeSH
- progesteron krev MeSH
- radioimunoanalýza MeSH
- rozmnožování MeSH
- velikost snůšky * MeSH
- vitelogeneze MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Madagaskar MeSH
The effects of habitat loss on the distribution of populations are often linked with species specialization degree. Specialist species can be more affected by changes in landscape structure and local patch characteristics compared to generalist species. Moreover, the spatial scale at which different land covers (eg. habitat, cropland, urban areas) affect specialist species can be smaller. Specialization is usually assumed as a constant trait along the distribution range of species. However, for several taxa, there is evidence of higher specialization degree in peripheral populations compared with populations in the core. Hence, peripheral populations should have a higher sensitivity to habitat loss, and strongest effects should be found at a smaller spatial scale. To test these expectations, we implemented a patch-landscape approach at different spatial scales, and compared effects of landscape structure and patch characteristics on occupancy probability among northern peripheral, more specialized populations (Czech Republic) and core populations (Bulgaria) of the eastern green lizard Lacerta viridis. We found that landscape structure and patch characteristics affect differently the occupancy probability of Lacerta viridis in each region. Strongest effects of habitat loss were found at a spatial scale of 150m around patches in the periphery, but at a scale of 500m in the core. In the periphery occupancy probability of populations was principally affected by landscape composition, and the effect of habitat quality was stronger compared to core populations. In the core, persistence of populations was mainly explained by characteristics of the spatial configuration of habitat patches. We discuss possible ecological mechanisms behind the relationship between sensitivity to habitat loss, populations' specialization degree and position in the distribution range, and suggest conservation measures for L. viridis.
- MeSH
- ekologie metody MeSH
- ekosystém MeSH
- ještěři růst a vývoj MeSH
- pravděpodobnost MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Bulharsko MeSH
- Česká republika MeSH
BACKGROUND: The accumulation of repetitive sequences such as microsatellites during the differentiation of sex chromosomes has not been studied in most squamate reptiles (lizards, amphisbaenians and snakes), a group which has a large diversity of sex determining systems. It is known that the Bkm repeats containing tandem arrays of GATA tetranucleotides are highly accumulated on the degenerated W chromosomes in advanced snakes. Similar, potentially homologous, repetitive sequences were found on sex chromosomes in other vertebrates. Using FISH with probes containing all possible mono-, di-, and tri-nucleotide sequences and GATA, we studied the genome distribution of microsatellite repeats on sex chromosomes in two lizard species (the gecko Coleonyx elegans and the lacertid Eremias velox) with independently evolved sex chromosomes. The gecko possesses heteromorphic euchromatic sex chromosomes, while sex chromosomes in the lacertid are homomorphic and the W chromosome is highly heterochromatic. Our aim was to test whether microsatellite distribution on sex chromosomes corresponds to the stage of their heteromorphism or heterochromatinization. Moreover, because the lizards lie phylogenetically between snakes and other vertebrates with the Bkm-related repeats on sex chromosomes, the knowledge of their repetitive sequence is informative for the determination of conserved versus convergently evolved repetitive sequences across vertebrate lineages. RESULTS: Heteromorphic sex chromosomes of C. elegans do not show any sign of microsatellite accumulation. On the other hand, in E. velox, certain microsatellite sequences are extensively accumulated over the whole length or parts of the W chromosome, while others, including GATA, are absent on this heterochromatinized sex chromosome. CONCLUSION: The accumulation of microsatellite repeats corresponds to the stage of heterochromatinization of sex chromosomes rather than to their heteromorphism. The lack of GATA repeats on the sex chromosomes of both lizards suggests that the Bkm-related repeats on sex chromosomes in snakes and other vertebrates evolved convergently. The comparison of microsatellite sequences accumulated on sex chromosomes in E. velox and in other eukaryotic organisms suggests that historical contingency, not characteristics of particular sequences, plays a major role in the determination of which microsatellite sequence is accumulated on the sex chromosomes in a particular lineage.
- MeSH
- genom MeSH
- heterochromatin MeSH
- hybridizace in situ fluorescenční MeSH
- ještěři genetika MeSH
- mikrosatelitní repetice genetika MeSH
- pohlavní chromozomy genetika MeSH
- repetitivní sekvence nukleových kyselin MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
