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Zoological Science, Volume 28, Issue 11, Page 802-808, November 2011.
Background:Efforts to solve higher-level evolutionary relationships within the class Insecta by using mitochondrial genomic data are hindered due to fast sequence evolution of several groups, most notably Hymenoptera, Strepsiptera, Phthiraptera, Hemiptera and Thysanoptera. Accelerated rates of substitution on their sequences have been shown to have negative consequences in phylogenetic inference. In this study, we tested several methodological approaches to recover phylogenetic signal from whole mitochondrial genomes. As a model, we used two classical problems in insect phylogenetics: The relationships within Paraneoptera and within Holometabola. Moreover, we assessed the mitochondrial phylogenetic signal limits in the deeper Eumetabola dataset, and we studied the contribution of individual genes.Results:Long-branch attraction (LBA) artefacts were detected in all the datasets. Methods using Bayesian inference outperformed maximum likelihood approaches, and LBA was avoided in Paraneoptera and Holometabola when using protein sequences and the site-heterogeneous mixture model CAT. The better performance of this method was evidenced by resulting topologies matching generally accepted hypotheses based on nuclear and/or morphological data, and was confirmed by cross-validation and simulation analyses. Using the CAT model, the order Strepsiptera was recovered as sister to Coleoptera for the first time using mitochondrial sequences, in agreement with recent results based on large nuclear and morphological datasets. Also the Hymenoptera-Mecopterida association was obtained, leaving Coleoptera and Strepsiptera as the basal groups of the holometabolan insects, which coincides with one of the two main competing hypotheses. For the Paraneroptera, the currently accepted non-monophyly of Homoptera was documented as a phylogenetic novelty for mitochondrial data. However, results were not satisfactory when exploring the entire Eumetabola, revealing the limits of the phylogenetic signal that can be extracted from Insecta mitogenomes. Based on the combined use of the five best topology-performing genes we obtained comparable results to whole mitogenomes, highlighting the important role of data quality.Conclusion:We show for the first time that mitogenomic data agrees with nuclear and morphological data for several of the most controversial insect evolutionary relationships, adding a new independent source of evidence to study relationships among insect orders. We propose that deeper divergences cannot be inferred with the current available methods due to sequence saturation and compositional bias inconsistencies. Our exploratory analysis indicates that the CAT model is the best dealing with LBA and it could be useful for other groups and datasets with similar phylogenetic difficulties.
Publication year: 2011
Source: Comparative Immunology, Microbiology and Infectious Diseases, Available online 21 October 2011
Sally Cutler, Alemseged Abdissa, Haileeysus Adamu, Tadele Tolosa, Abebaw Gashaw
Head and clothing lice from Jimma, Ethiopia were investigated for pathogenic bacteria. Genomic DNA from pools of lice was subjected to PCR analysis forBartonellaspp.,Borreliaspp.Coxiella burnetii,Rickettsiaspp. andYersinia pestis. All 102 lice pools were negative for the afore mentioned pathogens, with the exception ofBartonellaspecies found among 6 of 65 (9.2%) head lice pools and1 of 33 clothing lice pools. Identification was achieved by sequencing the ribosomal intragenic transcribed spacer region (ITS), revealing all to beBartonella quintana. Although established as a clothing louse-borne infection, typically causing chronic bacteraemia, trench fever, bacillary angiomatosis and endocarditis, this has only been rarely reported among head lice. The higher numbers of infected head lice pools compared with clothing lice suggests their competence for maintaining this infection within Ethiopia.
Background:Mitochondria are thought to have evolved from eubacteria-like endosymbionts; however, the origin of the mitochondrion remains a subject of debate. In this study, we investigated the phenomenon of chimerism in mitochondria to shed light on the origin of these organelles by determining which species played a role in their formation. We used the mitochondria of four distinct organisms, Reclinomonas americana, Homo sapiens, Saccharomyces cerevisiae and multichromosome Pediculus humanus, and attempted to identify the origin of each mitochondrial gene.Results:Our results suggest that the origin of mitochondrial genes is not limited to the Rickettsiales and that the creation of these genes did not occur in a single event, but through multiple successive events. Some of these events are very old and were followed by events that are more recent and occurred through the addition of elements originating from current species. The points in time that the elements were added and the parental species of each gene in the mitochondrial genome are different to the individual species. These data constitute strong evidence that mitochondria do not have a single common ancestor but likely have numerous ancestors, including proto-Rickettsiales, proto-Rhizobiales and proto-Alphaproteobacteria, as well as current alphaproteobacterial species. The analysis of the multichromosome P. humanus mitochondrion supports this mechanism.Conclusions:The most plausible scenario of the origin of the mitochondrion is that ancestors of Rickettsiales and Rhizobiales merged in a proto-eukaryotic cell approximately one billion years ago. The fusion of the Rickettsiales and Rhizobiales cells was followed by gene loss, genomic rearrangements and the addition of alphaproteobacterial elements through ancient and more recent recombination events. Each gene of each of the four studied mitochondria has a different origin, while in some cases, multichromosomes may allow for enhanced gene exchange. Therefore, the tree of life is not sufficient to explain the chimeric structure of current genomes, and the theory of a single common ancestor and a top-down tree does not reflect our current state of knowledge. Mitochondrial evolution constitutes a rhizome, and it should be represented as such.Reviewers: This article was revised by William Martin, Arcady Mushegian and Eugene V. Koonin.
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Publication year: 2011
Source: Review of Palaeobotany and Palynology, Available online 12 October 2011
Jochen Heinrichs, M. Elena Reiner-Drehwald, Kathrin Feldberg, Matt von Konrat, Jörn Hentschel, ...
Examination of two pieces of amber from the mid-Cretaceous of Myanmar revealed seven inclusions of leafy liverworts that we assign to the extinctFrullania cretaceaHentschel et al. 2009. These inclusions show a suite of characters that were not visible in the type specimen ofF. cretacea. The new gametophytes consistently display rectangular to ovate underleaves that have two long-ciliate apical teeth in addition to 0–2 blunt lateral teeth. A narrow stylus is present on at least some leaves. The lobules usually form watersacs that are 1.2-2.3 times longer than wide, and are arranged at some distance from the stem. The observed combination of character states is not present in extant crown group lineages ofFrullania. A syninclusion in one of the amber pieces is interpreted as a detached gynoecium of a second CretaceousFrullaniaspecies and is described asF. baerlocheri, sp. nov. The subgynoecial underleaves of the syninclusion are suborbicular in shape, and allow for a separation of this species fromF. cretacea. The described amber inclusions are the oldest representatives of an extant genus of leafy liverworts known so far.
Highlights► We report amber inclusions of liverworts from the mid Cretaceous of Myanmar. ► The fossils are assigned to the extant genusFrullania. ► Underleaves, styli and fertile structures ofFrullania cretaceaare described for the first time. ► One inclusion is interpreted as a detached gynoecium and described asFrullania baerlocherisp. nov.
Publication year: 2011
Source: Biological Conservation, Available online 8 September 2011
Ã‡aÄŸan H.Â ÅžekercioÄŸlu, SeanÂ Anderson, ErolÂ AkÃ§ay, RaÅŸitÂ Bilgin, Ã–zgÃ¼n EmreÂ Can, ...
Turkey (TÃ¼rkiye) lies at the nexus of Europe, the Middle East, Central Asia and Africa. Turkeyâ€™s location, mountains, and its encirclement by three seas have resulted in high terrestrial, fresh water, and marine biodiversity. Most of Turkeyâ€™s land area is covered by one of three biodiversity hotspots (Caucasus, Irano-Anatolian, and Mediterranean). Of over 9000 known native vascular plant species, one third are endemic. However, our scientific knowledge of Turkeyâ€™s biodiversity and associated conservation challenges is insufficient, mainly due to limited research and language barriers. Addressing this gap is increasingly relevant as Turkeyâ€™s biodiversity faces severe and growing threats, especially from government and business interests. Turkey ranks 140th out of 163 countries in biodiversity and habitat conservation. Millennia of human activities have dramatically changed the original land and sea ecosystems of Anatolia, one of the earliest loci of human civilization. Nevertheless, the greatest threats to biodiversity have occurred since 1950, particularly in the past decade. Although Turkeyâ€™s total forest area increased by 5.9% since 1973, endemic-rich Mediterranean maquis, grasslands, coastal areas, wetlands, and rivers are disappearing, while overgrazing and rampant erosion degrade steppes and rangelands. The current â€œdevelopmentalist obsessionâ€, particularly regarding water use, threatens to eliminate much of what remains, while forcing large-scale migration from rural areas to the cities. According to current plans, Turkeyâ€™s rivers and streams will be dammed with almost 4000 dams, diversions, and hydroelectric power plants for power, irrigation, and drinking water by 2023. Unchecked urbanization, dam construction, draining of wetlands, poaching, and excessive irrigation are the most widespread threats to biodiversity. This paper aims to survey what is known about Turkeyâ€™s biodiversity, to identify the areas where research is needed, and to identify and address the conservation challenges that Turkey faces today. Preserving Turkeyâ€™s remaining biodiversity will necessitate immediate action, international attention, greater support for Turkeyâ€™s developing conservation capacity, and the expansion of a nascent Turkish conservation ethic.
Highlightsâ–º Exhibiting high topographic and climatic diversity, Turkey is mostly covered by three biodiversity hotspots (Caucasus, Irano-Anatolian, and Mediterranean). â–º Turkey ranks 140th out of 163 countries in biodiversity and habitat conservation, and threats have peaked in the past decade. â–º Developmentalist obsession, unchecked urbanization, dam construction, draining of wetlands, poaching, and excessive irrigation are the biggest threats. â–º Total forest area increased by 5.9% since 1973, but coasts, wetlands, rivers, grasslands, and endemic-rich Mediterranean chapparal are highly threatened. â–º Conserving Turkeyâ€™s biodiversity requires immediate action, environmental education, international attention, capacity building, and expanding the Turkish conservation ethic.
Publication year: 2011
Source: Basic and Applied Ecology, In Press, Corrected Proof, Available online 1 September 2011
Publication year: 2011
Source: International Journal for Parasitology, In Press, Accepted Manuscript, Available online 31 August 2011
ZoltÃ¡n, Vas , Louis, Lefebvre , Kevin P., Johnson , JenÅ‘, Reiczigel , Lajos, RÃ³zsa
Lice (Insecta: Phthiraptera) are ectoparasites that reduce host life expectancy and sexual attractiveness. Their taxonomic richness varies considerably among their hosts. Previous studies have already explored some important factors shaping louse diversity. An unexplored potential correlate of louse taxonomic richness is host behavioral flexibility. In this comparative study, we examine the relationship between louse generic richness, innovative capabilities (as a proxy for behavioral flexibility), and brain size while controlling for host species diversity, phylogeny, body size and research effort. Using data for 108 avian families, we found a highly significant positive relationship between host innovative capabilities and the taxonomic richness...
Graphical abstractÂ Graphical abstract:Â Â Highlights:Â â–º A potential correlate of louse taxonomic richness is host behavioral flexibility. â–º The relationships between louse richness, host innovation and brain size were examined. â–º Data from 108 avian families were used. â–º Positive co-variation of host innovative capabilities and amblyceran richness. â–º Host brain size has only a marginal impact on amblyceran richness.
The three-dimensional structures of two odorant binding proteins (OBPs) and one chemosensory protein (CSP) from a polyphagous ectoparasitoid Scleroderma guani (Hymenoptera: Bethylidae) were resolved bioinformatically. The results show that both SguaOBP1 and OBP2 are classic OBPs, whereas SguaCSP1 belongs to non-classic CSPs which are considered as the “Plus-C” CSP in this report. The structural differences between the two OBPs and between OBP and CSP are thoroughly described, and the structural and functional significance of the divergent C-terminal regions (e.g., the prolonged C-terminal region in SguaOBP2 and the additional pair of cysteines in SguaCSP1) are discussed. The immunoblot analyses with antisera raised against recombinant SguaOBP1, OBP2, and CSP1, respectively, indicate that two SguaOBPs are specific to antennae, whereas SguaCSP1, which are more abundant than OBPs and detected in both male and female wasps, expresses ubiquitously across different tissues.
We also describe the ultrastructure of the antennal sensilla types in S. guani and compare them to 19 species of parasitic Hymenoptera. There are 11 types of sensilla in the flagellum and pedicel segments of antennae in both male and female wasps. Seven of them, including sensilla placodea (SP), long sensilla basiconica (LSB), sensilla coeloconica (SC), two types of double-walled wall pore sensilla (DWPS-I and DWPS-II), and two types of sensilla trichodea (ST-I and ST-II), are multiporous chemosensilla. The ultralsturctures of these sensilla are morphologically characterized. In comparison to monophagous specialists, the highly polyphagous generalist ectoparasitoids such as S. guani possess more diverse sensilla types which are likely related to their broad host ranges and complex life styles. Our immunocytochemistry study demonstrated that each of the seven sensilla immunoreacts with at least one antiserum against SguaOBP1, OBP2, and CSP1, respectively. Anti-OBP2 is specifically labeled in DWPS-II, whereas the anti-OBP1 shows a broad spectrum of immunoactivity toward four different sensilla (LSB, SP, ST-I and ST-II). On the other hand, anti-CSP1 is immunoactive toward SP, DWPS-I and SC. Interestingly, a cross co-localization pattern between SguaOBP1 and CSP1 is documented for the first time. Given that the numbers of OBPs and CSPs in many insect species greatly outnumber their antennal sensilla types, it is germane to suggest such phenomenon could be the rule rather than the exception.
Journal of Parasitology, Volume 97, Issue 4, Page 593-595, August 2011.
Background:The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome.Results:Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia).Conclusions:Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the formation of minicircles in lice.
Publication year: 2012
Source: Applied Geography, Volume 32, Issue 2, March 2012, Pages 514-521
Robert A., Francis , Michael A., Chadwick
The term â€˜synurbicâ€™ is sometimes used within the more recent urban ecology literature to refer to a species that colonises or is found within urban ecosystems, but this is too simplistic an interpretation. We consider that the term should be reserved for species populations that have higher densities in urban compared to rural areas, as a quantifiable measure of preferential urban association. This paper clarifies the terms â€˜synurbicâ€™ and â€˜synurbizationâ€™ and considers some of the problems of defining â€˜urbanâ€™, before detailing some of the positive responses exhibited by urban species that may lead to synurbic populations. It may be particularly...
Â Highlights:Â â–º â€˜Synurbicâ€™ is a term poorly defined in urban ecology. â–º We propose a quantifiable definition of â€˜synurbicâ€™ to avoid generalisations. â–º Synurbic species have greater urban than rural population densities. â–º Positive responses to the urban environment that can lead to synurbic populations are reviewed.
Journal of Medical Entomology, Volume 48, Issue 4, Page 828-835, July 2011.
Journal of Medical Entomology, Volume 48, Issue 4, Page 822-827, July 2011.
Publication year: 2011
Source: Trends in Molecular Medicine, In Press, Corrected Proof, Available online 15 July 2011
AurÃ©lie, RenvoisÃ© , Vicky, Merhej , Kalliopi, Georgiades , Didier, Raoult
The order Rickettsiales comprises obligate intracellular bacteria that are the ancestors of modern eukaryotes. These bacteria infect various vectors and hosts, with some species being pathogenic to man. Rickettsiales have small, degraded genomes and provide a paradigm for increased pathogenicity despite gene loss; significant levels of genetic exchange occur between bacteria that infect the same host and with the eukaryotic hosts themselves. Crosstalk between host and bacteria appears to be mediated by a Type IV secretion system and proteins containing eukaryotic-like repeat motifs. Rickettsiales also manipulate host reproduction and induce host resistance to viruses. Manipulation of its host by Rickettsiales...
Publication year: 2011
Source: Advances in Marine Biology, Volume 59, 2011, Pages 1-36
Charles W., Walker , Rebecca J., Van Beneden , Annette F., Muttray , S. Anne, BÃ¶ttger , Melissa L., Kelley , ...
The human p53 tumour suppressor protein is inactivated in many cancers and is also a major player in apoptotic responses to cellular stress. The p53 protein and the two other members of this protein family (p63, p73) are encoded by distinct genes and their functions have been extensively documented for humans and some other vertebrates. The structure and relative expression levels for members of the p53 superfamily have also been reported for most major invertebrate taxa. The functions of homologous proteins have been investigated for only a few invertebrates (specifically, p53 in flies, nematodes and recently a sea anemone). These...
The Hippoboscidae (Insecta: Diptera) from Madagascar, with new records from the "Parc National de Midongy Befotaka".
Parasite. 2011 May;18(2):127-40
Authors: Rahola N, Goodman SM, Robert V
The Hippoboscidae or "louse-flies" is a family of pupiparous Diptera, which in their adult stage are ectoparasites of mammals and birds. This paper presents a comprehensive review of Malagasy Hippoboscidae. In total, amongst the 213 species of this family known worldwide, 14 have been reported in Madagascar, among which six are considered as endemic to the Malagasy region. In addition, data are presented from a collection of 17 Hippoboscidae obtained from seven species of forest-dwelling birds in the "Parc National de Midongy Befotaka", southeastern Madagascar, in 2003. The flies in this collection belong to three different species: Icosta malagasii (one), Ornithoica podicipis (ten) and Ornithoctona laticomis (six). The two former species were previously only known from single specimens in museum collections; the later species is distributed across much of the Afrotropical region and the records presented herein are the first for Madagascar. All the seven bird species are new hosts for hippoboscids. We present the first description of the male of Icosta malagasii. An illustrated dichotomous determination key of the 14 Malagasy species, based on morphological criteria only, is presented.
PMID: 21678788 [PubMed - in process]
Journal of Raptor Research, Volume 45, Issue 2, Page 188-193, June 2011.
Acta Chiropterologica, Volume 13, Issue 1, Page 207-215, June 2011.