Gomez-Zurita J.,Institute Of Biologia Evolutiva Csic Upf
Zootaxa | Year: 2011
The Chrysomelidae of New Caledonia are rich and unique, but insufficiently characterized. New species are being rapidly described, sometimes without careful study of the earlier taxonomic research. Karl M. Heller (Dresden, Germany) de-scribed in 1916 seven species of Eumolpinae which are redescribed here to distinguish them from other known species and to provide new information about sexual dimorphism and genitalic structures. New material is used to redefine their distribution. The males of Dematochroma lepros (Heller, 1916) and D. culminicola (Heller, 1916), and the female of D. difficilis (Heller, 1916) are described for the first time. Male and female genitalia are first described for seven and five species, respectively. D. difficilis (Heller, 1916) stat. rev., is revalidated from previous synonymy with D. terastiomerus (Heller, 1916). Lectotypes are designated for D. humboldtiana and D. terastiomerus. Copyright © 2011 Magnolia Press.
Gomez-Zurita J.,Institute Of Biologia Evolutiva Csic Upf
ZooKeys | Year: 2011
The study of external morphology of the New Caledonian leaf beetle Dematochroma foaensis Jolivet, Verma& Mille (Chrysomelidae, Eumolpinae, Colaspoidini) substantiates its new combination into the genus Rhyparida Baly (Chrysomelidae, Eumolpinae, Nodinini). The species is redescribed here to highlight characters important for suprageneric diagnosis. This is the second species of Nodinini found in New Caledonia, otherwise rich in species of Colaspoidini, raising questions about the paucity of Rhyparida and this tribe in New Caledonian fauna, when they are dominant in surrounding archipelagoes, and very rich in potential source areas such as Australia and New Guinea. Some alternative explanations for this pattern are advanced, serving as alternative hypotheses until our knowledge on the ecology of these species improves or supported phylogenetic scenarios become available for this group. © Jesús Gómez-Zurita.
Talavera G.,Institute Of Biologia Evolutiva Csic Upf |
Talavera G.,University of Barcelona |
Vila R.,Institute Of Biologia Evolutiva Csic Upf
BMC Evolutionary Biology | Year: 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. © 2011Talavera and Vila; licensee BioMed Central Ltd.
Valverde S.,University Pompeu Fabra |
Valverde S.,Institute Of Biologia Evolutiva Csic Upf |
Valverde S.,University of Venice
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016
When looking at the history of technology, we can see that all inventions are not of equal importance. Only a few technologies have the potential to start a new branching series (specifically, by increasing diversity), have a lasting impact in human life and ultimately became turning points. Technological transitions correspond to times and places in the past when a large number of novel artefact forms or behaviours appeared together or in rapid succession. Why does that happen? Is technological change continuous and gradual or does it occur in sudden leaps and bounds? The evolution of information technology (IT) allows for a quantitative and theoretical approach to technological transitions. The value of information systems experiences sudden changes (i) whenwe learn howto use this technology, (ii) whenwe accumulate a large amount of information, and (iii) when communities of practice create and exchange free information. The coexistence between gradual improvements and discontinuous technological change is a consequence of the asymmetric relationship between complexity and hardware and software. Using a cultural evolution approach, we suggest that sudden changes in the organization of ITs depend on the high costs of maintaining and transmitting reliable information. © 2016 The Author(s) Published by the Royal Society. All rights reserved.
Lozano J.,Institute Of Biologia Evolutiva Csic Upf |
Kayukawa T.,Japan National Institute of Agrobiological Science |
Shinoda T.,Japan National Institute of Agrobiological Science |
Belles X.,Institute Of Biologia Evolutiva Csic Upf
PLoS Genetics | Year: 2014
Recent studies in vitro have reported that the Methoprene-tolerant (Met) and Taiman (Tai) complex is the functional receptor of juvenile hormone (JH). Experiments in vivo of Met depletion have confirmed this factor's role in JH signal transduction, however, there is no equivalent data regarding Tai because its depletion in larval or nymphal stages of the beetle Tribolium castaneum and the bug Pyrrhocoris apterus results in 100% mortality. We have discovered that the cockroach Blattella germanica possesses four Tai isoforms resulting from the combination of two indels in the C-terminal region of the sequence. The presence of one equivalent indel-1 in Tai sequences in T. castaneum and other species suggests that Tai isoforms may be common in insects. Concomitant depletion of all four Tai isoforms in B. germanica resulted in 100% mortality, but when only the insertion 1 (IN-1) isoforms were depleted, mortality was significantly reduced and about half of the specimens experienced precocious adult development. This shows that Tai isoforms containing IN-1 are involved in transducing the JH signal that represses metamorphosis. Reporter assays indicated that both T. castaneum Tai isoforms, one that contains the IN-1 and another that does not (DEL-1) activated a JH response element (kJHRE) in Krüppel homolog 1 in conjunction with Met and JH. The results indicate that Tai is involved in the molecular mechanisms that repress metamorphosis, at least in B. germanica, and highlight the importance of distinguishing Tai isoforms when studying the functions of this transcription factor in development and other processes. © 2014 Lozano et al.
Andujar C.,University of Murcia |
Serrano J.,University of Murcia |
Gamez-Zurita J.,Institute Of Biologia Evolutiva Csic Upf
BMC Evolutionary Biology | Year: 2012
Background: Rates of molecular evolution are known to vary across taxa and among genes, and this requires rate calibration for each specific dataset based on external information. Calibration is sensitive to evolutionary model parameters, partitioning schemes and clock model. However, the way in which these and other analytical aspects affect both the rates and the resulting clade ages from calibrated phylogenies are not yet well understood. To investigate these aspects we have conducted calibration analyses for the genus Carabus (Coleoptera, Carabidae) on five mitochondrial and four nuclear DNA fragments with 7888 nt total length, testing different clock models and partitioning schemes to select the most suitable using Bayes Factors comparisons. Results: We used these data to investigate the effect of ambiguous character and outgroup inclusion on both the rates of molecular evolution and the TMRCA of Carabus. We found considerable variation in rates of molecular evolution depending on the fragment studied (ranging from 5.02% in cob to 0.26% divergence/My in LSU-A), but also on analytical conditions. Alternative choices of clock model, partitioning scheme, treatment of ambiguous characters, and outgroup inclusion resulted in rate increments ranging from 28% (HUWE1) to 1000% (LSU-B and ITS2) and increments in the TMRCA of Carabus ranging from 8.4% (cox1-A) to 540% (ITS2). Results support an origin of the genus Carabus during the Oligocene in the Eurasian continent followed by a Miocene differentiation that originated all main extant lineages. Conclusions: The combination of several genes is proposed as the best strategy to minimise both the idiosyncratic behaviors of individual markers and the effect of analytical aspects in rate and age estimations. Our results highlight the importance of estimating rates of molecular evolution for each specific dataset, selecting for optimal clock and partitioning models as well as other methodological issues potentially affecting rate estimation. © 2012 Andújar et al; licensee BioMed Central Ltd.
Irles P.,Institute Of Biologia Evolutiva Csic Upf |
Piulachs M.-D.,Institute Of Biologia Evolutiva Csic Upf
Insect Biochemistry and Molecular Biology | Year: 2011
Molecular aspects of chorion synthesis in insects have been studied deeply in species with meroistic ovaries. Information available in insects with panoistic ovaries is principally structural whereas molecular information in these species is scarce. This paper seeks to balance the above situation by describing a novel chorion gene, Citrus, from the cockroach Blattella germanica, a phylogenetically basal hemimetabolan insect with reproduction regulated by juvenile hormone and with panoistic ovaries. During previous work we discovered a series of novel genes which were specifically expressed during chorion formation in B. germanica. One of them, herein named Citrus, was peculiar due to its high copy number and its very transient expression. In the present paper we characterize Citrus in terms of structure and function. The most prominent structural feature is that the protein contains a motif which is repeated 33 times encompassing almost all the sequence. By using RNAi techniques we have demonstrated that Citrus is a key player in the building of the endochorion of B. germanica eggs. © 2010 Elsevier Ltd.
Dinca V.,Institute Of Biologia Evolutiva Csic Upf |
Dinca V.,Autonomous University of Barcelona |
Dapporto L.,Instituto Comprensivo Materna Elementere Media Convenevole da Prato |
Vila R.,Institute Of Biologia Evolutiva Csic Upf
Molecular Ecology | Year: 2011
Widespread species have the potential to reveal large-scale biogeographical patterns, as well as responses to environmental changes possibly unique to habitat generalists. This study presents a continental-scale phylogeographical analysis of Polyommatus icarus, one of the most common Palaearctic butterflies, and the morphologically and ecologically similar Polyommatus celina, a recently discovered cryptic species. By combining data from mitochondrial [cytochrome c oxidase subunit I (COI)] and nuclear [internal transcribed spacer (ITS2)] molecular markers with geometric morphometrics, we document a complex phylogeographical history for the two species. Despite morphological similarities, the genetic divergence between these two species is high (more than 5% at COI) and they are not sister species. For the first time, we show that P. celina occurs not only in North Africa but also in Europe, where it inhabits several west Mediterranean islands, as well as large parts of Iberia, where it occurs in parapatry with P. icarus. The two species appear to completely exclude each other on islands, but we provide morphological and molecular evidence that introgression occurred in the Iberian Peninsula. We discovered strongly diverged lineages that seem to represent relict populations produced by past range expansions and contractions: Crete and Iberian isolates for P. icarus, Balearics-Sardinia and Sicily-Lipari for P. celina. This study shows that a combined genetic-morphometric approach can shed light on cryptic diversity while providing the necessary resolution to reconstruct a fine-scale phylogeographical history of species at both spatial and temporal levels. © 2011 Blackwell Publishing Ltd.
Soria-Carrasco V.,Institute Of Biologia Evolutiva Csic Upf |
Soria-Carrasco V.,University of Sheffield |
Castresana J.,Institute Of Biologia Evolutiva Csic Upf
Proceedings of the Royal Society B: Biological Sciences | Year: 2012
The latitudinal gradient of species richness has frequently been attributed to higher diversification rates of tropical groups. In order to test this hypothesis for mammals, we used a set of 232 genera taken from a mammalian supertree and, additionally, we reconstructed dated Bayesian phylogenetic trees of 100 genera. For each genus, diversification rate was estimated taking incomplete species sampling into account and latitude was assigned considering the heterogeneity in species distribution ranges. For both datasets, we found that the average diversification rate was similar among all latitudinal bands. Furthermore, when we used phylogenetically independent contrasts, we did not find any significant correlation between latitude and diversification parameters, including different estimates of speciation and extinction rates. Thus, other factors, such as the dynamics of dispersal through time, may be required to explain the latitudinal gradient of diversity in mammals.
Suren-Castillo S.,Institute Of Biologia Evolutiva Csic Upf |
Abrisqueta M.,Institute Of Biologia Evolutiva Csic Upf |
Maestro J.L.,Institute Of Biologia Evolutiva Csic Upf
Insect Biochemistry and Molecular Biology | Year: 2012
The transcription factor Forkhead-box O (FoxO) is the main transcriptional effector of the Insulin Receptor/Phosphatidylinositol 3-kinase (InR/PI3K) pathway. In a situation of nutrient restriction, the pathway is inactive and FoxO translocates to the nucleus to exert its transcriptional action. In starved females of the cockroach . Blattella germanica, the reproductive processes, and in particular the synthesis of juvenile hormone in the corpora allata and that of vitellogenin in the fat body, are arrested. In the present report we examine the possible role of FoxO in the transduction of the nutritional signals to these reproductive events. We first cloned FoxO cDNA from . B. germanica (BgFoxO), and showed that its expression is not nutritionally regulated. BgFoxO knockdown using systemic RNAi . in vivo in starved females elicited an increase of juvenile hormone biosynthesis, although without modifying mRNA levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase-1, HMG-CoA synthase-2, HMG-CoA reductase or methyl farnesoate epoxidase (CYP15A1) in corpora allata. In addition, BgFoxO RNAi treatment produced a remarkable increase of vitellogenin mRNA levels in fat body and of vitellogenin protein in the haemolymph. Our results indicate that BgFoxO plays an inhibitory role on juvenile hormone biosynthesis and vitellogenin production in a situation of nutrient shortage. © 2012 Elsevier Ltd.