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1.
J Helminthol ; 94: e97, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31679527

RESUMO

Several factors influence the dynamics and structure of parasite communities. Our goal was to investigate how the community composition, prevalence and abundance of parasites change across seven populations of the exotic lizard Hemidactylus mabouia in Northeast Brazil, and to describe ontogenetic and sex variations. We found differences in the composition of component communities and patterns of infection according to the host body size across the lizard populations. We did not find any variation between the sexes regarding epidemiological patterns, which can probably be explained by the similar diet and habitat use of male and female H. mabouia. An unusually high abundance and prevalence of trematodes infecting this host lizard was apparent when we compared other native lizard hosts, and we suggest that local environmental conditions might be advantageous to the development and life cycle of these parasites due to the abundance of all the intermediate and definitive hosts.


Assuntos
Lagartos/parasitologia , Parasitos/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Animais , Tamanho Corporal , Brasil/epidemiologia , Ecossistema , Feminino , Lagartos/classificação , Lagartos/crescimento & desenvolvimento , Masculino , Parasitos/classificação , Parasitos/genética , Parasitos/fisiologia , Doenças Parasitárias em Animais/epidemiologia
2.
Zool Res ; 40(5): 456-465, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31502428

RESUMO

Mountain Dragons of the genus Diploderma Hallowell, 1861 were recently resurrected from the paraphyletic genus Japalura sensu lato (Wang et al., 2019a). Despite the recent split, Diploderma still represents one of the most diverse groups of agamid lizard from Asia, including 25 species recognized currently, with most species found in China ((Wang et al., 2019a, 2019b). Although increasing attention has been paid to cryptic diversity within the genus in Southwest China during the past decade, most studies have focused on a single species complex, D. flaviceps, only (Manthey et al., 2012; Wang et al., 2015, 2016, 2017, 2019a), with few studies on other congeners that also have widespread distributions. One such example is D. dymondi (Boulenger, 1906).


Assuntos
Distribuição Animal , Lagartos/classificação , Animais , China , DNA Mitocondrial/genética , Feminino , Lagartos/genética , Masculino , Filogenia , Especificidade da Espécie
3.
BMC Evol Biol ; 19(1): 178, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492110

RESUMO

BACKGROUND: Fossil evidence suggests that extant North American lizard genera (north of Mexico) evolved during the Miocene. Although fossils of the clade Phrynosomatidae (spiny lizards and sand lizards) have been reported, there have been no previously described fossils of the fringe-toed sand lizards (Uma). In the extant biota, Uma inhabit arid deserts, and members of the western clade of Uma are restricted to sand dunes or other habitats containing fine-grained sand. RESULTS: I describe the first known fossil of Uma and refer the fossil to the total clade of Uma with an apomorphy-based diagnosis. The fossil is a partial premaxilla that was found in the Miocene strata of the Dove Spring Formation of southern California, dating to 8.77 Ma. The paleoenvironment of the Dove Spring Formation was semiarid and contained ephemeral streams that facilitated deposition, and there is no evidence of sand dune deposits in the strata containing the locality from which the Uma fossil was found. Divergence time analyses of a concatenated molecular dataset with four fossil calibrations support a Neogene origin of the total clade of Uma and of the crown clade of Uma. Those analyses also estimated a Neogene divergence between Uma scoparia and the Uma notata complex. Multispecies coalescent analyses with one fossil calibration inferred a Paleogene origin for the total clade of Uma and a Pliocene or Pleistocene divergence between Uma scoparia and the Uma notata complex. The fossil and the total and crown clades of Uma precede the evolution of modern desert ecosystems in the southwestern United States and northern Mexico by millions of years. CONCLUSIONS: The total clade and the crown clade of Uma were not restricted to arid deserts throughout their evolutionary histories. I demonstrate that an apomorphy-based diagnosis can be used to identify fossils of isolated skeletal elements for at least one clade of phrynosomatid lizard, and suggest exercising caution when using environmental tolerances of extant taxa to hypothesize paleoecological reconstructions.


Assuntos
Fósseis , Lagartos/classificação , Lagartos/genética , Animais , Evolução Biológica , California , Ecologia , Ecossistema , Lagartos/anatomia & histologia , México , Filogenia
4.
Zoology (Jena) ; 134: 16-26, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31146904

RESUMO

Segmentation gives rise to the anterior-posterior axis in many animals, and in vertebrates this axis comprises serially arranged vertebrae. Modifications to the vertebral column abound, and a recurring, but functionally understudied, change is the elongation of the body through the addition and/or elongation of vertebrae. Here, we compared the vertebral and axial kinematics of the robustly limbed Fire skink (Riopa fernandi) representing the ancestral form, the limbless European glass lizard (Ophisaurus apodus), and the Northern water snake (Nerodia sipedon). We induced these animals to traverse through channels and peg arrays of varied widths and densities, respectively, using high-speed X-ray and light video. We found that even though the snake had substantially more and shorter vertebrae than either lizard, intervertebral joint angles did not differ between species in most treatment levels. All three species decreased the amplitude and wavelength of their undulations as channels narrowed and the lizard species increased wave frequency in narrower channels. In peg arrays, both lizard species decreased wave amplitude, while the snake showed no differences. All three species maintained similar wavelengths and frequencies as peg density increased in most cases. Our results suggest that amplitude is decoupled from wavelength and frequency in all three focal taxa. The combination of musculoskeletal differences and the decoupling of axial kinematic traits likely facilitates the formation of different undulatory waves, thereby allowing limbless species to adopt different modes of locomotion.


Assuntos
Extremidades , Articulações/anatomia & histologia , Lagartos/anatomia & histologia , Serpentes/anatomia & histologia , Coluna Vertebral/anatomia & histologia , Animais , Fenômenos Biomecânicos , Lagartos/classificação , Locomoção , Serpentes/classificação
5.
Zoology (Jena) ; 134: 8-15, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31146909

RESUMO

Pristurus rupestris is a member of Semaphore geckos with a wide distribution range. Recently, 14 candidate species of P. rupestris rupestris have been identified in the Hajar Mountains (Arabia), yet the knowledge on the Iranian counterparts is limited. The present study elucidates the phylogenetic position of the Iranian P. rupestris and investigates the hypothesis on its historical colonization from Oman to Iran and the associated islands. Therefore, 20 Iranian specimens along with 115 individuals from Oman were examined using two mitochondrial genes including the Cytochrome b and the 12S ribosomal RNA. The molecular phylogenetic analyses revealed that the individuals collected from Iran are well nested within the candidate Species 3 of P. r. rupestris, demonstrating a single population with high gene flow. Additionally, the molecular analyses showed that the genetic diversity within the Iranian Blanford's Semaphore geckos is low and that the candidate Species 3 experienced a recent expansion approximately 17 thousand years ago (Kya). The historical demographic analyses (BSP) showed a mild increase in the effective population size between 15-20 Kya. These time estimations coincide with the Last Glacial Maximum, when the Persian Gulf was almost dry, reinforcing the hypothesis that the species might have colonized southern Iran from Oman through the Persian Gulf. In addition, we propose P. r. iranicus to be synonymized with P. r. rupestris.


Assuntos
Lagartos/fisiologia , Filogenia , Animais , Haplótipos , Irã (Geográfico) , Lagartos/classificação , Lagartos/genética , Omã
6.
Nature ; 570(7759): 58-64, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31168105

RESUMO

Biological invasions are both a pressing environmental challenge and an opportunity to investigate fundamental ecological processes, such as the role of top predators in regulating biodiversity and food-web structure. In whole-ecosystem manipulations of small Caribbean islands on which brown anole lizards (Anolis sagrei) were the native top predator, we experimentally staged invasions by competitors (green anoles, Anolis smaragdinus) and/or new top predators (curly-tailed lizards, Leiocephalus carinatus). We show that curly-tailed lizards destabilized the coexistence of competing prey species, contrary to the classic idea of keystone predation. Fear-driven avoidance of predators collapsed the spatial and dietary niche structure that otherwise stabilized coexistence, which intensified interspecific competition within predator-free refuges and contributed to the extinction of green-anole populations on two islands. Moreover, whereas adding either green anoles or curly-tailed lizards lengthened food chains on the islands, adding both species reversed this effect-in part because the apex predators were trophic omnivores. Our results underscore the importance of top-down control in ecological communities, but show that its outcomes depend on prey behaviour, spatial structure, and omnivory. Diversity-enhancing effects of top predators cannot be assumed, and non-consumptive effects of predation risk may be a widespread constraint on species coexistence.


Assuntos
Biodiversidade , Cadeia Alimentar , Lagartos/fisiologia , Comportamento Predatório , Animais , Evolução Biológica , Biota , Comportamento Competitivo , Comportamento Alimentar , Feminino , Lagartos/classificação , Masculino , Especificidade da Espécie , Índias Ocidentais
7.
J Parasitol ; 105(3): 432-441, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31169454

RESUMO

Exotic species can threaten biodiversity by introducing parasites to native hosts. Thus, it is critical to identify if the same parasite species infects both native and exotic hosts. However, developmental- or environmental-induced morphological variation may render species identification ambiguous. Our study reports a range expansion in the southern United States of the pentastome Raillietiella indica from the Mediterranean gecko, Hemidactylus turcicus, as well as a host expansion into the green anole, Anolis carolinensis, in the anole's native range. Species identification was based on sequence data and male spicule shape. In agreement with a study from Australia, we found that much of the morphological variation in hook measurements, the primary diagnostic traits of raillietiellid pentastomes, was due to development. Here, we explicitly link this developmental variation to instar stage by incorporating experimental infection data obtained from the literature. We also show that the various hook traits are themselves highly correlated and, thus, likely not independent. Taking instar stage and correlated hook variables into account, we directly controlled for development on a composite hook size measurement. Using a large sample size from H. turcicus, we did not find any consistent effects of potential factors (host sex, host snout-vent-length, or parasite intensity) that may result in environmental-induced variation in relative hook size (corrected for body length). However, relative male spicule size tended to be negatively correlated with parasite intensity. In contrast, both pentastome body length and relative hook size significantly varied among host species whereas relative male spicule size was not significantly different among host species. Our study independently supports the conclusions that developmental- and host-induced morphological variations need to be accounted for to accurately identify pentastome species.


Assuntos
Cestoides/fisiologia , Infecções por Cestoides/veterinária , Lagartos/parasitologia , Animais , Tamanho Corporal , Cestoides/anatomia & histologia , Cestoides/classificação , Infecções por Cestoides/parasitologia , Feminino , Lagartos/anatomia & histologia , Lagartos/classificação , Masculino , Fatores Sexuais
8.
Mol Phylogenet Evol ; 138: 89-101, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31128241

RESUMO

Coalescent-based algorithms coupled with the access to genome-wide data have become powerful tools for assessing questions on recent or rapid diversification, as well as delineating species boundaries in the absence of reciprocal monophyly. In southern South America, the diversification of Liolaemus lizards during the Pleistocene is well documented and has been attributed to the climatic changes that characterized this recent period of time. Past climatic changes had harsh effects at extreme latitudes, including Patagonia, but habitat changes at intermediate latitudes of South America have also been recorded, including expansion of sand fields over northern Patagonia and Pampas). In this work, we apply a coalescent-based approach to study the diversification of the Liolaemus wiegmannii species complex, a morphologically conservative clade that inhabits sandy soils across northwest and south-central Argentina, and the south shores of Uruguay. Using four standard sequence markers (mitochondrial DNA and three nuclear loci) along with ddRADseq data we inferred species limits and a time-calibrated species tree for the L. wiegmannii complex in order to evaluate the influence of Quaternary sand expansion/retraction cycles on diversification. We also evaluated the evolutionary independence of the recently described L. gardeli and inferred its phylogenetic position relative to L. wiegmannii. We find strong evidence for six allopatric candidate species within L. wiegmannii, which diversified during the Pleistocene. The Great Patagonian Glaciation (∼1 million years before present) likely split the species complex into two main groups: one composed of lineages associated with sub-Andean sedimentary formations, and the other mostly related to sand fields in the Pampas and northern Patagonia. We hypothesize that early speciation within L. wiegmannii was influenced by the expansion of sand dunes throughout central Argentina and Pampas. Finally, L. gardeli is supported as a distinct lineage nested within the L. wiegmannii complex.


Assuntos
Algoritmos , Lagartos/classificação , Animais , Argentina , Teorema de Bayes , Citocromos b/genética , DNA Mitocondrial/genética , Loci Gênicos , Variação Genética , Genoma , Geografia , Lagartos/genética , Filogenia , Análise de Componente Principal , Especificidade da Espécie , Fatores de Tempo , Uruguai
9.
Mol Phylogenet Evol ; 138: 193-204, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31129348

RESUMO

The evolutionary history of taxa with limited overseas dispersal abilities is considered to be majorly influenced by vicariant events constituting them as model organisms for the interpretation of evolutionary processes. An excellent candidate are the wall lizards of the genus Podarcis exhibiting an impressive level of genetic and morphological diversification and harboring several cases of recently discovered cryptic diversity. In this study, we investigated the effect of palaeogeographic events on the wall lizards' biodiversity patterns in the Aegean (Greece) as well as the evolutionary processes that acted both in space and time. To accomplish that we studied a group of three endemic Podarcis species (i.e., P. cretensis, P. levendis, and P. peloponnesiacus) both at the intra and interspecific levels employing mitochondrial and nuclear DNA sequence data as well as microsatellites. Furthermore, presence information coupled with bioclimatic data (i.e., species distribution modeling, and niche similarity analyses) shed light on the necessary ecological factors for the species' occurrence. These approaches revealed yet another case of cryptic diversity for this group of lizards, with the existence of two slightly overlapping lineages within P. peloponnesiacus and highly structured populations within P. cretensis. Species diversification occurred during the Pliocene with P. peloponnesiacus divergence into the two lineages dating back to 1.86 Mya. Furthermore, temperature and precipitation related environmental parameters were the most important ones regarding the current distribution of the studied species. Based on the results, we propose a more detailed phylogeographic scenario where both the paleogeography of the area and several environmental parameters have shaped the genetic diversity and the current distribution pattern of this species group.


Assuntos
Lagartos/classificação , Filogenia , Filogeografia , Animais , Península Balcânica , Biodiversidade , DNA Mitocondrial/genética , Variação Genética , Genética Populacional , Grécia , Lagartos/genética , Repetições de Microssatélites/genética , Especificidade da Espécie , Fatores de Tempo
10.
Integr Comp Biol ; 59(1): 117-130, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30938766

RESUMO

An evolutionary perspective on gecko adhesion was previously hampered by a lack of an explicit phylogeny for the group and of robust comparative methods to study trait evolution, an underappreciation for the taxonomic and structural diversity of geckos, and a dearth of fossil evidence bearing directly on the origin of the scansorial apparatus. With a multigene dataset as the basis for a comprehensive gekkotan phylogeny, model-based methods have recently been employed to estimate the number of unique derivations of the adhesive system and its role in lineage diversification. Evidence points to a single basal origin of the spinulate oberhautchen layer of the epidermis, which is a necessary precursor for the subsequent elaboration of a functional adhesive mechanism in geckos. However, multiple gains and losses are implicated for the elaborated setae that are necessary for adhesion via van der Waals forces. The well-supported phylogeny of gekkotans has demonstrated that convergence and parallelism in digital design are even more prevalent than previously believed. It also permits the reexamination of previously collected morphological data in an explicitly evolutionary context. Both time-calibrated trees and recently discovered amber fossils that preserve gecko toepads suggest that a fully-functional adhesive apparatus was not only present, but also represented by diverse architectures, by the mid-Cretaceous. Further characterization and phylogenetically-informed analyses of the other components of the adhesive system (muscles, tendons, blood sinuses, etc.) will permit a more comprehensive reconstruction of the evolutionary pathway(s) by which geckos have achieved their structural and taxonomic diversity. A phylogenetic perspective can meaningfully inform functional and performance studies of gecko adhesion and locomotion and can contribute to advances in bioinspired materials.


Assuntos
Lagartos/fisiologia , Locomoção/fisiologia , Adesividade , Animais , Evolução Biológica , Fenômenos Biomecânicos , Lagartos/classificação , Filogenia
11.
Mol Phylogenet Evol ; 136: 183-195, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30965125

RESUMO

Trachylepis (Mabuyinae) includes ∼80 species of fully-limbed skinks found primarily in Africa and Madagascar, but a robust species-level phylogeny for this genus is lacking and this impedes studies on a wide-range of topics from biogeography to character evolution. Trachylepis and its close relatives (which together form the Mabuya group or Mabuyinae) are notable in that they have undergone multiple transitions and remarkable specializations in their reproductive modes. A Trachylepis phylogeny will be particularly useful for investigating reproductive evolution, because it includes species that exhibit oviparity, viviparity, and bimodal parity (species with both oviparous and viviparous populations). We sequenced DNA at four mitochondrial and five nuclear loci for 67 (∼84% of) Trachylepis species to infer a phylogeny for this genus. We performed stochastic character mapping of parity mode under a variety of parity mode transition models to infer ancestral parity mode states and the number and type of parity mode transitions. We recovered a strongly supported phylogeny of Trachylepis that is generally consistent with earlier phylogenetic studies. The best-fit model of reproductive mode evolution supports an oviparous ancestor for Trachylepis, and supports at least three viviparity to oviparity transitions. We compared parity mode evolution under the overall best-fit model (no constraints on parity mode transitions) to the best-fit model among the subset of models that assume viviparity to oviparity transitions are impossible. Our results support a model of reproductive evolution that allows for reversibility from viviparity to oviparity, a process that is not generally accepted. Alternatively, the best-fit model of evolution among the set of models that eliminate reversals from viviparity to oviparity suggests that bimodal reproduction may have persisted for millions of years within multiple lineages.


Assuntos
Lagartos/classificação , Filogenia , África , Animais , Sequência de Bases , Feminino , Loci Gênicos , Geografia , Lagartos/genética , Madagáscar , Reprodução/fisiologia , Especificidade da Espécie , Processos Estocásticos , Temperatura Ambiente
12.
Mol Phylogenet Evol ; 137: 300-312, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31029747

RESUMO

The lacertid lizards of the genus Mesalina inhabit the arid regions of the Old World, from North Africa to NW India. Of the 19 recognized species within the genus, eleven occur in Arabia. In this study, we explore the genetic variability and phylogeographic patterns of the less studied M. adramitana group from southern Arabia and the Socotra Archipelago within the phylogenetic and biogeographic context of the entire genus. Our unprecedented sampling extends the distribution ranges of most Mesalina species and, for the first time, sequences of M. ayunensis are included in a phylogenetic analysis. We perform analyses of concatenated multilocus datasets and species trees, conduct species delimitation analyses, and estimate divergence times within a biogeographic framework. Additionally, we inferred the environmental suitability and identified dispersal corridors through which gene flow is enabled within M. adramitana. Our results show that the Socotra Archipelago was colonized approximately 7 Mya by a single oversea colonization from mainland Arabia. Then, an intra-archipelago dispersal event that occurred approximately 5 Mya resulted in the speciation between M. balfouri, endemic to Socotra, Samha and Darsa Islands, and M. kuri, endemic to Abd al Kuri Island. Similar to previous studies, we uncovered high levels of genetic diversity within the M. adramitana species-group, with two highly divergent lineages of M. adramitana living in allopatry and adapted to locally specific climatic conditions that necessitate further investigation.


Assuntos
Ilhas , Lagartos/classificação , Filogeografia , África do Norte , Migração Animal , Animais , Arábia , Sequência de Bases , DNA Mitocondrial/genética , Ecossistema , Variação Genética , Lagartos/genética , Modelos Biológicos , Filogenia , Fatores de Tempo
13.
Cytogenet Genome Res ; 157(1-2): 115-122, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30820011

RESUMO

Pleurodont lizards are characterized by an ancient system of sex chromosomes. Along with stability of the central component of the system (homologous to the X chromosome of Anolis carolinensis [Dactyloidae], ACAX), in some genera the ancestral sex chromosomes are fused with microautosomes, forming neo-sex chromosomes. The genus Ctenonotus (Dactyloidae) is characterized by multiple X1X1X2X2/X1X2Y sex chromosomes. According to cytogenetic data, the large neo-Y chromosome is formed by fusion of the ancestral Y chromosome with 2 microautosomes (homologous to ACA10 or ACA11 and ACA12), the X1 chromosome is formed by fusion of the ancestral X chromosome with the autosome homologous to ACA10 or ACA11, and the X2 chromosome is homologous to autosome ACA12. To determine more precisely the content and evolution of the Ctenonotus sex chromosomes, we sequenced flow-sorted chromosomes (both sex chromosomes and microautosomes as control) of 2 species with a similar system: C. pogus and C. sabanus. Our results indicate that the translocated part of the X1 is homologous to ACA11, X2 is homologous to ACA12, and the Y contains segments homologous to both ACA11 and ACA12. Molecular divergence estimates suggest that the ancestral X-derived part has completely degenerated in the Y of Ctenonotus, similar to the degeneration of the Norops sagrei Y chromosome (Dactyloidae). The newly added regions show loss of DNA content, but without degeneration of the conserved regions. We hypothesize that the translocation of autosomal blocks onto sex chromosomes facilitated rapid degeneration of the pseudoautosomal region on the ancestral Y.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Lagartos/genética , Cromossomo X/genética , Cromossomo Y/genética , Animais , Coloração Cromossômica/métodos , Cromossomos/genética , DNA/química , DNA/genética , DNA/metabolismo , Feminino , Lagartos/classificação , Masculino , Especificidade da Espécie , Translocação Genética
14.
Cytogenet Genome Res ; 157(1-2): 65-76, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30836364

RESUMO

The common lizard (Zootoca vivipara) displays characteristic cytogenetic, reproductive, molecular, and biogeographic variability. This species comprises oviparous and viviparous populations with disjunct distribution and sex chromosome polymorphisms, from simple ZZ/ZW to complex Z1Z1Z2Z2/Z1Z2W systems with different morphologies of the W chromosome. In this study, we used the primers SINE A and SINE B and a newly designed primer pair to (1) obtain information on the presence and distribution of transposable elements (TEs) in 8 squamate families and (2) assess the chromosomal location of SINE Squam elements in Z. vivipara. PCR amplification with SINE A and SINE B produced single or multiple products in different Z. vivipara populations, subsequently used to design the SINE-Zv primers. Using the newly designed SINE-Zv primers, we identified 2 sequences of about 700 and 300 bp (SINE-Zv 700 and SINE-Zv 300) in all the investigated populations of Z. vivipara. Fluorescence in situ hybridizations showed a preferential localization of SINE-Zv sequences in the peritelomeric regions of almost all chromosomes, with the exception of the W. Both sequences contained a distinct segment of SINE Squam2. SINE-Zv 700 appeared to be restricted to Z. vivipara, while SINE-Zv 300 contained a partial Gypsy sequence that is highly conserved among Squamata and showed high identity values (72-93%) with several transcripts from different species. Using the same primers, we also highlighted the presence of another highly conserved Gypsy-like fragment in snakes which displayed significant similarity with the stomatin-like protein 2 of colubrids. Our results suggest that SINEs and the Gypsy-like elements are widely distributed among squamates and may have played an active role in their genomic evolution and differentiation.


Assuntos
Elementos de DNA Transponíveis/genética , Lagartos/genética , Répteis/genética , Cromossomos Sexuais/genética , Elementos Nucleotídeos Curtos e Dispersos/genética , Animais , Sequência de Bases , Evolução Molecular , Feminino , Hibridização in Situ Fluorescente , Lagartos/classificação , Masculino , Filogenia , Répteis/classificação , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie
15.
J Parasitol ; 105(1): 113-123, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807719

RESUMO

Legless lizards (Amphisbaenia) belong to a group of mostly legless squamates that include about 196 species. One genus ( Bipes) retains a pair of forelimbs, but all other 19 genera in the clade are limbless. They are widely distributed, occurring in the Middle East and the Caribbean and nearly all of the major continents (except Australia). Only 2/6 (33%) families, 3/20 (15%) genera, and 4/195 (2%) species in the Amphisbaenia clade of the Sauria have been examined for coccidia and 8 coccidia species are now known. Here, we summarize information on the 8 species of coccidia (3 Choleoeimeria, 1 Eimeria, 4 Isospora) reported from legless lizards of the world. In addition, Eimeria amphisbaeniarum Huntington, Cisper, Smith, Powell, Parmerlee Jr., and Lathrop, 1996, is placed in the genus Choleoeimeria. We speculate that another 380 intestinal coccidia infecting this unique reptilian lineage wait to be discovered.


Assuntos
Eimeriidae/classificação , Lagartos/parasitologia , Animais , Eimeriidae/ultraestrutura , Lagartos/classificação
16.
PLoS One ; 14(2): e0212683, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30794668

RESUMO

Telomeric sequences are generally located at the ends of chromosomes; however, they can also be found in non-terminal chromosomal regions when they are known as interstitial telomeric sequences (ITSs). Distribution of ITSs across closely related and divergent species elucidates karyotype evolution and speciation as ITSs provide evolutionary evidence for chromosome fusion. In this study, we performed physical mapping of telomeric repeats by fluorescence in situ hybridisation (FISH) in seven Australian dragon lizards thought to represent derived karyotypes of squamate reptiles and a gecko lizard with considerably different karyotypic feature. Telomeric repeats were present at both ends of all chromosomes in all species, while varying numbers of ITSs were also found on microchromosomes and in pericentromeric or centromeric regions on macrochromosomes in five lizard species examined. This suggests that chromosomal rearrangements from ancestral squamate reptiles to Iguania occurred mainly by fusion between ancestral types of acrocentric chromosomes and/or between microchromosomes, leading to appearance of bi-armed macrochromosomes, and in the reduction of microchromosome numbers. These results support the previously proposed hypothesis of karyotype evolution in squamate reptiles. In addition, we observed the presence of telomeric sequences in the similar regions to heterochromatin of the W microchromosome in Pogona barbata and Doporiphora nobbi, while sex chromosomes for the two species contained part of the nucleolar organiser regions (NORs). This likely implies that these ITSs are a part of the satellite DNA and not relics of chromosome fusions. Amplification of telomeric repeats may have involved heterochromatinisation of sex-specific W chromosomes and play a role in the organisation of the nucleolus.


Assuntos
Evolução Molecular , Lagartos/genética , Cromossomos Sexuais/genética , Telômero/genética , Animais , Austrália , Lagartos/classificação , Especificidade da Espécie
17.
Mol Phylogenet Evol ; 134: 1-11, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30703515

RESUMO

Complex geological processes often drive biotic diversification on islands. The islands of Sumatra and Java have experienced dramatic historical changes, including isolation by marine incursions followed by periodic connectivity with the rest of Sundaland across highland connections. To determine how this geological history influenced island invasions, we investigated the colonization history and diversification of bent-toed geckos (genus Cyrtodactylus) on Sumatra and west Java. We used mitochondrial and nuclear sequence data to explore species boundaries, estimate phylogenetic relationships and divergence times, and to reconstruct ancestral range evolution. We found that Sumatran and Javan Cyrtodactylus were closely related to species from the Thai-Malay Peninsula, rather than from Borneo, and that Cyrtodactylus most likely dispersed to Sumatra three times during the late Oligocene and early Miocene. Similarly, Cyrtodactylus invaded west Java from Sumatra once in the early Miocene. Our results suggest that despite isolation by marine incursions during much of the Miocene, Cyrtodactylus dispersed to and from Sumatra and west Java likely via land bridges, and that in situ diversification occurred several times on Sumatra.


Assuntos
Biodiversidade , Lagartos/classificação , Animais , Teorema de Bayes , Calibragem , Fósseis , Geografia , Indonésia , Ilhas , Funções Verossimilhança , Filogenia , Especificidade da Espécie
18.
Cytogenet Genome Res ; 157(1-2): 107-114, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30677759

RESUMO

Meiotic recombination rates and patterns of crossover distributions along the chromosomes vary considerably even between closely related species. The adaptive significance of these differences is still unclear due to the paucity of empirical data. Most data on recombination come from mammalian species, while other vertebrate clades are poorly explored. Using immunolocalization of the protein of the lateral element of the synaptonemal complex (SYCP3) and the mismatch-repair protein MLH1, which marks mature recombination nodules, we analyzed recombination rates and crossover distribution in meiotic prophase chromosomes of the steppe agama (Trapelus sanguinolentus, Agamidae, Acrodonta, Iguania) and compared them with data obtained for the genus Anolis (Dactyloidae, Pleurodonta, Iguania). We found that, despite a smaller genome size, the total SC length and the MLH1 focus number per cell are much higher in the agama than in the anoles. The distributions of the MLH1 foci in the agama are multimodal in larger chromosomes and bimodal in smaller chromosomes without a significant centromere effect, resembling the patterns known for birds. A possible relationship between karyotype remodeling and the evolution of recombination in Iguania is discussed.


Assuntos
Recombinação Homóloga , Lagartos/genética , Meiose/genética , Complexo Sinaptonêmico/genética , Animais , Centrômero/genética , Troca Genética/genética , Tamanho do Genoma , Cariótipo , Lagartos/classificação , Masculino , Proteína 1 Homóloga a MutL/genética , Especificidade da Espécie
19.
Mol Phylogenet Evol ; 133: 166-175, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30641271

RESUMO

The Socotra Archipelago in the Arabian Sea is considered one of the most geo-politically isolated landforms on earth and a center of endemism. The archipelago is located at the western edge of the Indian Ocean and comprises four islands: Socotra, Darsa, Samha, and Abd al Kuri. Here we provide an integrative study on Haemodracon geckos, the sole genus of geckos strictly endemic to the archipelago. The sympatric distribution of Haemodracon riebeckii and H. trachyrhinus on Socotra Island provides a unique opportunity to explore evolutionary relationships and speciation patterns, examining the interplay between possible sympatric and allopatric scenarios. We used molecular data for phylogenetic inference, species delimitation analyses, and to infer the diversification timeframe. Multivariate statistics were used to analyze morphological data. Ecological comparisons were explored for macro-niches using species distribution models and observations were used for micro-habitat use. Haemodracon species exhibit great levels of intraspecific genetic diversity. Our calibration estimates revealed that Haemodracon diverged from its closest relative, the mainland genus Asaccus, in the Eocene, before the detachment of the archipelago. The two Haemodracon species diversified in situ on Socotra Island during the Middle Miocene, after the archipelago's isolation, into the two reciprocally monophyletic recognized species. Their divergence is associated mostly with remarkable body size differences and micro-habitat segregation, with low levels of climatic and body shape divergences within their sympatric distributions. These results display how ecological, sympatric speciation, and allopatric speciation followed by secondary contact, may both have varying roles at different evolutionary phases.


Assuntos
Ecossistema , Ilhas , Lagartos/genética , Animais , Especiação Genética , Variação Genética , Oceano Índico , Lagartos/classificação , Filogenia , Filogeografia
20.
Mitochondrion ; 46: 149-157, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29689383

RESUMO

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.


Assuntos
Citocromos b/genética , DNA Mitocondrial/genética , Variação Genética , Lagartos/classificação , Lagartos/genética , Animais , República Tcheca , Haplótipos , Masculino , Crescimento Demográfico
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