Search

Nowadays it is widely accepted that parasites play a significant role in the community structures in which they occur, and ultimately upon ecosystems. Furthermore, infection by parasites might be associated with considerable deterioration of individual host fitness. While the apicomplexan parasites belonging to the genus Hepatozoon can provoke severe deleterious effects in some mammals, impact on other hosts, such as reptiles, is still unclear. We assessed the effect of Hepatozoon parasites on Podarcis vaucheri flight-initiation distance from a simulated predator, a behaviour that is determinant for a successful escape and is therefore likely to have major implications on a lizard’s survival. We found that flight-initiation distance was not dependent on the time of the day or tail condition. Subadults exhibited worse body condition than adults and females had worse body condition than males. Regarding intensity of parasitism, subadults showed higher parasitemia levels. Escape distance was not associated with parasitic load or any of the other studied features, which is indicative of limited impact of the parasite. This negligible effect might explain the remarkably high prevalence (more than 96%) of this parasitic group within this P. vaucheri population.

Mitochondrial genomes are known to have a strong strand-specific compositional bias that is more pronounced at fourfold redundant sites of mtDNA protein-coding genes. This observation suggests that strand asymmetries, to a large extent, are caused by mutational asymmetric mechanisms. In vertebrate mitogenomes, replication and not transcription seems to play a major role in shaping compositional bias. Hence, one can better understand how mtDNA is replicated--a debated issue--through a detailed picture of mitochondrial genome evolution. Here, we analyzed the compositional bias (AT and GC skews) in protein-coding genes of almost 2,500 complete vertebrate mitogenomes. We were able to identify three fish mitogenomes with inverted AT/GC skew coupled with an inversion of the Control Region. These findings suggest that the vertebrate mitochondrial replication mechanism is asymmetric and may invert its polarity, with the leading-strand becoming the lagging-strand and vice-versa, without compromising mtDNA maintenance and expression. The inversion of the strand-specific compositional bias through the inversion of the Control Region is in agreement with the strand-displacement model but it is also compatible with the RITOLS model of mtDNA replication.

Identifying factors influencing infection patterns among hosts is critical for our understanding of the evolution and impact of parasitism in natural populations. However, the correct estimation of infection parameters depends on the performance of detection and quantification methods. In this study, we designed a quantitative PCR (qPCR) assay targeting the 18 S rRNA gene to estimate prevalence and intensity of Hepatozoon infection and compared its performance with microscopy and PCR. Using qPCR, we also compared various protocols that differ in the biological source and the extraction methods. Our results show that the qPCR approach on DNA extracted from blood samples, regardless of the extraction protocol, provided the most sensitive estimates of Hepatozoon infection parameters; while allowed us to differentiate between mixed infections of Adeleorinid (Hepatozoon) and Eimeriorinid (Schellackia and Lankesterella), based on the analysis of melting curves. We also show that tissue and saline methods can be used as low-cost alternatives in parasitological studies. The next step was to test our qPCR assay in a biological context, and for this purpose we investigated infection patterns between two sympatric lacertid species, which are naturally infected with apicomplexan hemoparasites, such as the genera Schellackia (Eimeriorina) and Hepatozoon (Adeleorina). From a biological standpoint, we found a positive correlation between Hepatozoon intensity of infection and host body size within each host species, being significantly higher in males, and higher in the smaller sized host species. These variations can be associated with a number of host intrinsic factors, like hormonal and immunological traits, that require further investigation. Our findings are relevant as they pinpoint the importance of accounting for methodological issues to better estimate infection in parasitological studies, and illustrate how between-host factors can influence parasite distributions in sympatric natural populations.

While traditionally species recognition has been based solely on morphological differences either typological or quantitative, several newly developed methods can be used for a more objective and integrative approach on species delimitation. This may be especially relevant when dealing with cryptic species or species complexes, where high overall resemblance between species is coupled with comparatively high morphological variation within populations. Rock lizards, genus Darevskia, are such an example, as many of its members offer few diagnostic morphological features. Herein, we use a combination of genetic, morphological and ecological criteria to delimit cryptic species within two species complexes, D. chlorogaster and D. defilippii, both distributed in northern Iran. Our analyses are based on molecular information from two nuclear and two mitochondrial genes, morphological data (15 morphometric, 16 meristic and four categorical characters) and eleven newly calculated spatial environmental predictors. The phylogeny inferred for Darevskia confirmed monophyly of each species complex, with each of them comprising several highly divergent clades, especially when compared to other congeners. We identified seven candidate species within each complex, of which three and four species were supported by Bayesian species delimitation within D. chlorogaster and D. defilippii, respectively. Trained with genetically determined clades, Ecological Niche Modeling provided additional support for these cryptic species. Especially those within the D. defilippii-complex exhibit well-differentiated niches. Due to overall morphological resemblance, in a first approach PCA with mixed variables only showed the separation between the two complexes. However, MANCOVA and subsequent Discriminant Analysis performed separately for both complexes allowed for distinction of the species when sample size was large enough, namely within the D. chlorogaster-complex. In conclusion, the results support four new species, which are described herein.

LEÃO, Liana de Camargo; SANTOS, Marlene Soares. Shakespeare, sua época e sua obra. Curitiba: Beatrice, 2008. 360 p. ISBN: 978856078000-6.

This article discusses one of Virginia Woolf’s greatest literary concerns: the difficulty of expressing human experience through language. The focus is on The Voyage Out, her first novel, published in 1915, particularly the conflicts and contrasts present not only in the trajectory of Rachel Vinrace, the main character, but also in the structure of the novel itself, which establish a constant tension between reality and language.

The only Italian population of the lacertid Psammodromus algirus is found in Conigli islet whereas the species is absent from the nearby island of Lampedusa. The phylogeographic relationships of this population were investigated. Mitochondrial DNA (12S rRNA and 16S rRNA) fragment sequences were analysed and compared with already published sequences from the whole species range. In all the analyses, the sample from Conigli grouped with those from Morocco and not with the closer Tunisian ones. Such surprising result poses serious doubts to the traditional interpretation of the enigmatic distribution pattern of this species in Italy suggesting a recent colonisation of the islet from NW Africa, probably human-mediated, rather than a land crossing from Tunisia during the Pleistocene.

Baseado numa análise da Electra de Sófocles, propõe-se que a preocupação central do dramaturgo não é o matricídio da Clitemnestra em si. Sófocles convida a platéia a refletir, como se fosse o júri num tribunal, a respeito da legalidade das ações da Electra. Desta forma, a peça é uma contribuição ao debate sobre a Justiça na sociedade grega iniciado quase dois séculos antes.

Aim Diversification and rapid radiation are well documented in lacertid lizards. Niche conservation is frequently observed among related taxa, whereby niches will not change much during speciation events. Here, we investigate the relationship between environmental niche divergence and phylogenetic relatedness in a widespread group of green lizards, the Lacerta trilineata group. Location Eastern Mediterranean, Anatolia and adjacent regions. Methods A dated phylogeny based on three mitochondrial genes was contextualized using species distribution models of all genetically identified lineages in the Lacerta trilineata group. Based on this analysis, ancestral climatic niche occupancy was reconstructed using niche occupancy profiles. Niche divergence among lineages was quantified by computing multivariate niche overlaps. Results All taxa are associated with humid areas, but there is extensive variation in their climatic niche breadths and positions, which accord with the main phylogenetic split in the group. Our results suggest divergent niche evolution within subclades and convergent evolution among clades, which implies only a limited degree of niche conservatism regarding annual variations in temperature and precipitation. In contrast, niche axes - mainly reflecting precipitation patterns of the coldest quarter - show a greater difference among clades than within clades, and therefore a higher degree of niche conservatism. Main conclusions Based on estimated divergence times between taxa and geological events in Anatolia, our results can be explained by fragmentation of the range of a hypothetical ancestral species, resulting in different adaptations of subclades either to humid continental climates or to more Mediterranean climates. Our study highlights deviations from classical niche conservatism theory due to significant niche shifts among sister taxa. [ABSTRACT FROM AUTHOR]

The implementation of molecular tools in parasitology has led to the discovery of numerous cryptic species. However, detailed morphological studies are needed to evaluate the cryptic nature of such species, as well as to provide an appropriate and formal description. Recent phylogenetic analyses using mitochondrial and nuclear genes have revealed that the nematode Spauligodon atlanticus, parasite of lizards of the genus Gallotia endemic to the Canary Islands, consists of two highly divergent and unrelated lineages, one in the eastern islands and the other in the western ones. This study provides a detailed morphological analysis of the two S. atlanticus lineages characterized genetically, based on body measurements and scanning electron microscopy. This integrative approach revealed phenotypic differences between them, despite their overall morphological resemblance. As a result, the new species Spauligodon occidentalis sp. nov., from the formerly western lineage, is described. The morphological similarity between the two Spauligodon species is better explained on the basis of evolutionary convergence, since both species parasitize Gallotia lizards. In addition to delimiting the new nematode species, this study highlights the importance of combining genetic and morphological data with taxonomy to uncover the nature of cryptic species and decrease taxonomic uncertainty. [ABSTRACT FROM AUTHOR]

Abstract: Genetic diversity is critical for conservation of endemic populations. It enhances adaptation to rapid environmental changes and persistence over evolutionary time-scales. In small and isolated populations, such as on islands, this is even more relevant. Nevertheless, few studies regarding the establishment of protected areas (PAs) on islands have taken genetic diversity into account. The Cape Verde Islands are in a biodiversity hotspot and present to resource planners unique problems and possibilities, hence are a good case study. This work primarily aims to compare targeting evolutionary significant units (ESUs) versus species in reserve selection algorithms for the conservation of the endemic Cape Verdean reptile diversity by assessing the PAs network adequacy, identifying its gaps, and optimizing it based on ‘realistic’ (considering areas inside PAs with lower cost) and ‘ideal’ (considering all non-humanized areas with higher potential for conservation) cost scenarios. Results clearly indicate that analyses targeting ESUs are more effective in the protection of genetic diversity and less costly in terms of selected area, in total and inside PAs. Results also indicate that most ESUs and species are insufficiently protected and that extra PAs are needed on most islands to reach conservation targets. Surprisingly, the total area selected in ‘ideal’ and ‘realistic’ prioritization scenarios are identical on most islands both for analyses targeting ESUs or species. Therefore the ‘realistic’ scenario should be largely followed. The work provides an innovative methodological framework for supporting the use of genetic diversity in reserve design and its results should assist in local-scale conservation planning. [Copyright &y& Elsevier]

[Display omitted] • First DNA study of all sub-Saharan African & Seychelles natricine snake genera (70% of species). • Sub-Saharan African and Seychelles natricines are monophyletic. • Lycognathophis seychellensis likely sister to (Afronatrix (Helophis , Hydraethiops)). • L. seychellensis is not a Gondwanan relic, but dispersed to the Seychelles from Africa. • Low genetic variation in L. seychellensis across five Seychelles islands. Phylogenetic relationships of sub-Saharan African natricine snakes are understudied and poorly understood, which in turn has precluded analyses of the historical biogeography of the Seychelles endemic Lycognathophis seychellensis. We inferred the phylogenetic relationships of Seychelles and mainland sub-Saharan natricines by analysing a multilocus DNA sequence dataset for three mitochondrial (mt) and four nuclear (nu) genes. The mainland sub-Saharan natricines and L. seychellensis comprise a well-supported clade. Two maximally supported sets of relationships within this clade are (Limnophis,Natriciteres) and (Afronatrix ,(Hydraethiops,Helophis)). The relationships of L. seychellensis with respect to these two lineages are not clearly resolved by analysing concatenated mt and nu data. Analysed separately, nu data best support a sister relationship of L. seychellensis with (Afronatrix ,(Hydraethiops,Helophis)) and mt data best support a sister relationship with all mainland sub-Saharan natricines. Methods designed to cope with incomplete lineage sorting strongly favour the former hypothesis. Genetic variation among up to 33 L. seychellensis from five Seychelles islands is low. Fossil calibrated divergence time estimates support an overseas dispersal of the L. seychellensis lineage to the Seychelles from mainland Africa ca. 43–25 million years before present (Ma), rather than this taxon being a Gondwanan relic. [ABSTRACT FROM AUTHOR]

Tortoise ticks, Hyalomma aegyptium, are considered so strongly associated with their hosts that they are even used as indirect indicators for them. In such a case, a robust pattern of congruence between host and parasite could be expected, with phylogeographic breaks within the host being reflected in their parasites. We sequenced two mitochondrial partial gene regions (12S rRNA and Cytochrome Oxidase 1) from ticks across northern Africa and Anatolia, and compared patterns of variation with those identified in its main host, Testudo graeca. Two distinct haplogroups were identified, both of which were found distributed across much of northern Africa. This pattern does not reflect the known variation within the host, which has multiple, geographically disjunct subspecies in this region, but rather the major climatic zones. This relationship can be explained by adaptive processes to environmental conditions influenced by the climate, as well as by the spatial structure of the communities of tick potential hosts in larval and nymphal stages. Extensive anthropogenic movement of tortoises may also obscure congruence patterns between H. aegyptium ticks and their hosts., (Copyright © 2022 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Catastrophic fractures or luxations (FoL) sustained during recovery from general anesthesia are a significant cause of mortality during equine anesthesia. There is a lack of evidence regarding potential risk factors for a FoL occurring in the immediate anesthetic recovery period. A single center, retrospective, case-matched study was performed to identify risk factors for sustaining a catastrophic FoL during recovery from general anesthesia. Clinical data were obtained for horses which sustained a catastrophic FoL when recovering from general anesthesia from January 2011 to June 2020 in a single center referral population. Multivariable logistical regression analysis was performed to identify risk factors which were significant in horses where a FoL occurred. Statistically significant risk factors in our population of horses of sustaining a FoL in recovery included intraoperative administration of intratracheal salbutamol, intraoperative administration of ketamine and increasing age. Further research in this area, particularly with regards to salbutamol administration, is required., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Tissue samples from wildlife from South Africa were opportunistically collected and screened for haemoprotozoan parasites using nonspecific PCR primers. Samples of 127 individuals were tested, comprising over 50 different species. Haemogregarines were the most commonly identified parasites, but sarcocystids and piroplasmids were also detected. Phylogenetic analyses estimated from the 18S rDNA marker highlighted the occurrence of several novel parasite forms and the detection of parasites in novel hosts. Phylogenetic relationships, which have been recently reviewed, appear to be much more complex than previously considered. Our study highlights the high diversity of parasites circulating in wildlife in this biodiverse region, and the need for further studies to resolve taxonomic issues.

Water frogs, Pelophylax perezi, that are introduced in the Azores, were screened for parasites using PCR primers known to amplify Apicomplexa parasites, and using nematode-specific primers. With the former, three different organisms were detected: Hepatozoon, a trichodinid protozoan ciliate and a possible Stramenopile. Using the latter set of primers, a single unknown spirurid nematode was also detected. Phylogenetic analyses indicate that Hepatozoon detected within amphibian hosts appear to form a clade, although relationships of these parasites do not match the vertebrate intermediate host phylogeny. Regarding the possible Stramenopile, it is unclear whether this organism was actually present on the amphibian or in the water on the surface of the tissue sample. Our findings highlight that many different organisms can be detected with these primers and that they can be used to screen introduced host populations to detect parasites that have been brought with them.

Lizards of the genus Trachylepis are a species-rich group of skinks mainly inhabiting Africa, Madagascar, and several other islands in the western Indian Ocean. All except one probably introduced species of Madagascan Trachylepis are endemic. Two species groups have been distinguished on the basis of subocular scale shape but their phylogenetic relationships remained unclear. We inferred a multilocus phylogeny of the Madagascan Trachylepis species, based on a concatenated dataset of 3261 bp from 3 mitochondrial and 4 nuclear genes with a dense Madagascan taxon sampling and find high support for the monophyly of the endemic Madagascan Trachylepis. The two species groups in Madagascar are highly supported as clades. The highland species T. boettgeri is nested in the T. aureopunctata species group of mainly arid-adapted species, suggesting a colonization of highland swamps by ancestors inhabiting dry western Madagascar. The Seychellois species were sister to the T. maculilabris/T. comorensis clade, suggesting their origin directly out of Africa as with Seychellois chameleons. In Madagascar, a high intraspecific molecular variation was confirmed for T. gravenhorstii, T. elegans, and T. vato, indicating a need for taxonomic revision., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We analyse for the first time the genetic diversity within Ptyodactylus oudrii across the Maghreb. Two mitochondrial (12s rRNA and 16s rRNA) and two nuclear (C-mos and ACM4) markers are used. The results confirm the specific status of P. oudrii and show high levels of intraspecific variability, indicative of species complex. Lineages found are geographically concordant, and show similar patterns to that found in other species from the region. The study highlights once more the importance of the region as a source of genetic diversity., (Copyright (c) 2009 Elsevier Inc. All rights reserved.)

We sequenced the complete control region (CR) and adjacent tRNAs, partial 12S rRNA, and cytochrome b (over 3100 bp) from eight individuals of Madeiran wall lizards, Lacerta dugesii, from four distinct island populations. The tRNAs exhibit a high degree of intraspecific polymorphisms compared to other vertebrates. All CR sequences include a minisatellite that varies in length between populations but is apparently fixed within them. Variation in minisatellite length appears between populations separated by apparently very short evolutionary time spans. Many motifs identified in the CR of other vertebrates are not highly conserved, although conserved blocks are identifiable between the few published reptile CR sequences. Overall there are extensive differences in the internal organization of the reptile CR compared to the more widely studied mammals and birds. Variability in the CR is lower than in cytochrome b, but higher than in 12S rRNA. Phylogenetic analysis of these sequences produces a well-resolved estimate of relationships between populations.