Variação geográfica, zonas de intergradação e especiação no complexo Icterus Cayanensis-Chrysocephalus (Aves : Icteridae)

O complexo Icterus cayanensis-chtysocephalus apresenta um intrincado padrão de variação em plumagem e tamanho corpóreo. São reconhecidos, tradicionalmente, para o grupo seis táxons: Icterus chtysocephalus, I. cayanensis cayanensís. I. cayanensis tibialis, I. cayanensis tibialis, I. cayanensis valenciobuenoi, I. cayanensis periporphyrus e I. cayanensis pyrrhopterus, que se substituem geograficamente ao longo de grande parte da América do Sul. Neste estudo foi feita a descrição dos padrões de variação geográfica. Foram diagnosticadas quatro espécies, à luz do conceito filogenético de espécie: Icterus cayanensis (Amazônia Meridional), Icterus chrysocephalus (Amazônia Setentrional), Icterus tibialis (Caatinga) e Icterus pyrrhopterus (Chaco); os táxons I. cayanensis valenciobuenoi e I. cayanensis periporphyrus foram sinonimizados. Entre as formas amazonicas (chrysocephalus e cayanensis) foi detectada a presença de uma zona híbrida mais extensa do que aquela reportada na literatura. No Brasil Central foi diagnosticada a maior zona de intergradação conhecida para aves, com aproximadamente 2.300 km de extensão, produto do intercruzamento entre Icterus tibialis e Icterus pyrrhopterus, formas distribuídas pela Caatinga e Chaco, respectivamente. Postula-se que as zonas de intergradação diagnosticadas neste estudo são produto do intercruzamento de populações previamente diferenciadas em isolamento geográfico.

Revisão sistemática e biogeografia da espécie politípica campylorhamphus procurvoides

A última revisão do gênero Campylorhamphus (realizada por Zimmer em 1934), definiu a espécie politípica C. procurvoides como constituída pelos seguintes táxons de diagnose tradicionalmente difícil, feita principalmente com base em caracteres de plumagem: C. p. procurvoides, C. p multostriatus, C. p. probatus, C. p. sanus e C. p. successor. O objetivo do presente estudo foi revisar a sistemática desta espécie politípica através da descrição da variação geográfica e análise crítica da validade dos táxons atualmente reconhecidos, utilizando-se caracteres morfológicos e moleculares. A análise molecular indicou com forte apoio estatístico que a espécie politípica de C. procurvoides é polifilética, uma vez que os táxons nela agrupados se encontram distribuídos em três clados distintos e não proximamente relacionado dentro do gênero Campylorhamphus. Uma análise combinada dos caracteres morfológicos e genéticos possibilitou a diagnose objetiva dos táxons procurvoides, ultostriatus, probatus e sanus, mas não de successor, que foi sinonimizada com um táxon agrupado numa outra espécie politípica (C. t. notabilis); esta mesma análise indicou a existência de dois táxons distintos previamente não reconhecidos e que aqui são diagnosticados e referidos como taxon novum 1 e táxon novum 2. Com base nas suas relações fologenéticas e diagnose consistente, os táxons considerados válidos nesta revisão e tradicionalmente tratados como subespécies de C. procurvoides, são aqui elevados ao nível de espécie com base no Conceito Filético Geral de Espécie.

Variação morfológica, vocal e genética na espécie politípica Lepidocolaptes albolineatus (Aves – Dendrocolaptidae)

Lepidocolaptes albolineatus (Aves: Dendrocolaptidae) é uma espécie biológica politípica, constituída pelos seguintes táxons: L. a. albolineatus, que ocorre na Área de Endemismo (AE) Guiana, L. a. duidae (AE Imeri), L .a. fuscicapillus (AE Rondônia), L. a. madeirae (AE Rondônia) e L. a .layardi (AEs Tapajós, Xingu e Belém). Os objetivos deste trabalho foram: (1) revisar a validade e a diagnosabilidade dos táxons atualmente agrupados em L. albolineatus com base em caracteres morfológicos, vocais e moleculares e (2) reavaliar os limites interespecíficos entre estes táxons. Foram mensurados 150 espécimes depositados em 8 museus do Brasil e EUA. Para a análise molecular, foram seqüenciados um total de 940 pb do gene mitocondrial ND2 para 35 indivíduos de todos os táxons de L. albolineatus. As análises filogenéticas foram realizadas nos programa PAUP 4.0 b 10 e MrBayes 3.1 utilizando-se os métodos de parcimônia (MP), máxima verossimilhança (MV) e inferência Bayesiana. A combinação de dados morfológicos e moleculares revelou a existência de 5 clados fortemente apoiados estatisticamente: clado 1 (agrupando indivíduos da AE Rondônia), clado 2 (agrupando espécimes das AE Belém, Xingu e Tapajós), clado 3 (incluindo espécimes da AE Inambari), clado 4 (incluindo indivíduos da AE Imeri) e clado 5 (agrupando indivíduos da AE Guiana). Todos os clados corresponderam a táxons já nomeados, exceto o clado 3 para o qual nenhum nome válido se encontra disponível, já que o nome fuscicapillus na verdade se aplica ao clado 1 e, portanto, deve ser considerado sinônimo sênior de madeirae. A principal separação genética e morfológica em L. albolineatus acontece entre o táxon nominal e os demais, embora cada um dos 5 clados possa ser considerado uma espécie distinta (com base no Conceito Filético Geral de Espécie) através de uma combinação única de caracteres morfológicos, vocais e moleculares diagnósticos.

Vergleichende Phylogenie der Gimpel (Aves: Fringillidae: Pyrrhula Brisson, 1760)

Mit dieser Arbeit wird am Beispiel der Gimpel der Gattung Pyrrhula (Aves: Fringillidae) eine vergleichende phylogenetische Methodik angewandt. Der dafür gewählte Untersuchungsansatz beinhaltet v.a. molekulargenetische und morphologische Methoden, deren Ergebnisse vor dem biogeographischen Hintergrund der Gattung analysiert werden. Diese Arbeit bestätigt die traditionelle Abgrenzung der Gimpel gegenüber den anderen Formen der Finkenfamilie. Die Gattung stellt eine monophyletische Gruppe dar und ist sowohl anhand molekulargenetischer als auch morphologischer Merkmale hervorragend umgrenzbar. Eine Vereinigung mit der Schwestergattung Pinicola ist demgegenüber nicht gerechtfertigt. Die mit klassischen Untersuchungsverfahren bestimmten Gruppierungen der Gattung lassen sich auch mit modernen Methoden bestätigen. Pyrrhula besteht aus drei Hauptverwandtschaftsgruppen: „Südostasiatische Gimpel“ (P. nipalensis und P. leucogenis), „Himalayagimpel“ (P. aurantiaca, P. erythaca, P. erythrocephala) und „Eurasische Gimpel“ (P. pyrrhula s.l.). Innerhalb von P. pyrrhula s.l. lassen sich drei genetisch und morphologisch unterschiedlich differenzierte Untergruppierungen mit eigenständige Merkmalskombinationen ausmachen: P. (p.) murina, P. (p.) cineracea und P. (p.) griseiventris. Das Entstehungszentrum von Pyrrhula befand sich vermutlich im südöstlichen Asien. Anhand der molekulargenetischen und biogeographischen Daten lassen sich ungefähre Ausbreitungs- und Diversifizierungsprozesse datieren. Vom Entstehungszentrum ging eine präpleistozäne Ausbreitungswelle aus, die die Aufspaltung der Stammlinienvertreter der Südostasiatischen Gimpel und später die der Himalayagimpel-Stammlinie zur Folge hatten. Etwa zeitgleich begann die Ausbreitung der Vorfahren der Eurasischen Gimpel bis ins westliche Südeuropa. Im frühen Pleistozän spalteten sich die Vorläufer des rezenten P. aurantica ab, gefolgt von der Trennung der südostasiatischen Stammlinie in die Vorfahren von P. nipalensis und P. leucogenis. Daraufhin folgten rasche spätpleistozäne Ausbreitungen und Diversifizierungen, die das Überdauern von Gimpeln in südostchinesischen bzw. mediterranen Glazialrefugien nahelegen. Dabei trennten sich die Stammlinien von P. erythrocephala und P. erythaca ungefähr gleichzeitig mit jenen der Stammlinien von P. pyrrhula s.str., P. (p.) murina und P. (p.) griseiventris. Die P. (p.) cineracea-Stammlinie folgte wiederum etwas später. Die Vorläufer der heutigen P. pyrrhula s.str. nahmen im späten Pleistozän mehrfach ostwärts gerichtete Ausbreitungen vor, während derer sie sich über weite Teile Eurasiens bis nach Kamtschatka verbreiteten. Die morphologischen Differenzierungen der einzelnen Formen wurden wahrscheinlich stark durch die geographischen Verhältnisse beeinflusst. Neben Isolationseffekten auf Inseln (murina) spielten vermutlich auch pleistozäne Refugialgebiete der Mandschurei und Japans für die Entstehung der heutigen griseiventris und das nordmongolische Refugium für cineracea eine große Rolle. Der gefiedermorphologische Geschlechtsmonomorphismus von P. nipalensis und P. leucogenis könnte dabei einen stammesgeschichtlich ancestralen Zustand darstellen, jener von murina ist dagegen sicher eine sekundäre Reduktionserscheinung. Auf Grundlage des Biospezieskonzeptes erlauben die erarbeiteten phylogenetischen Daten, die Gattung Pyrrhula entweder in sechs oder in neun Arten (inkl. zweier Superspezies) zu unterteilen. Der zahlenmäßige Unterschied entsteht dabei durch die unterschiedliche Klassifikation der Formen murina, cineracea und griseiventris, die entweder P. pyrrhula als Subspezies angeschlossen werden oder als Angehörige einer Superspezies P. [pyrrhula] Artrang erhalten.

Silicoflagellates of DSDP Leg 90 sites

Silicoflagellates are described from Sites 588 (middle Eocene), 591 (middle Miocene to lower Pliocene), and 594 (middle Miocene to Quaternary) in the southwest Pacific. At Sites 591 and 594 a detailed silicoflagellate zonation is possible, although there are some obvious differences arising from the latitudinal position of the sites in the silicoflagellate assemblages. Comparison between the sequences recovered at Sites 591 and 206 (Leg 21) revealed two hiatuses in the latter, but helped to establish a zonation for this area from the lower Miocene to the Pleistocene and a correlation to standard nannoplankton zones. The stratigraphic implications of the taxonomy used by various authors and the species concept presented here are discussed in detail. Special reference is made to types described by Ehrenberg and to later synonyma, because the Ehrenberg collection is the base for all subsequent descriptions and evaluations of silicoflagellate taxa. Two new genera (Neonaviculopsis, Paramesocena), two new subspecies (Dictyocha fibula subsp. asymmetrica, Neonaviculopsis neonautica subsp. praenautica), and three new forms (Dictyocha perlaevis f. pentaradiata, Distephanus speculum subsp. speculum f. nonarius, and Mesocena ? hexalitha f. heptalitha) are described from the southwest Pacific Neogene and Pleistocene. Associated sponge spicules were noted and will be described in detail in a later paper, but some are documented on Plate 13.

Genome-Wide Prediction Methods in Highly Diverse and Heterozygous Species: Proof-of-Concept through Simulation in Grapevine.

Nowadays, genome-wide association studies (GWAS) and genomic selection (GS) methods which use genome-wide marker data for phenotype prediction are of much potential interest in plant breeding. However, to our knowledge, no studies have been performed yet on the predictive ability of these methods for structured traits when using training populations with high levels of genetic diversity. Such an example of a highly heterozygous, perennial species is grapevine. The present study compares the accuracy of models based on GWAS or GS alone, or in combination, for predicting simple or complex traits, linked or not with population structure. In order to explore the relevance of these methods in this context, we performed simulations using approx 90,000 SNPs on a population of 3,000 individuals structured into three groups and corresponding to published diversity grapevine data. To estimate the parameters of the prediction models, we defined four training populations of 1,000 individuals, corresponding to these three groups and a core collection. Finally, to estimate the accuracy of the models, we also simulated four breeding populations of 200 individuals. Although prediction accuracy was low when breeding populations were too distant from the training populations, high accuracy levels were obtained using the sole core-collection as training population. The highest prediction accuracy was obtained (up to 0.9) using the combined GWAS-GS model. We thus recommend using the combined prediction model and a core-collection as training population for grapevine breeding or for other important economic crops with the same characteristics.

Two new species of Zetzellia Oudemans (Acari: Stigmaeidae) that threaten the concept of genera: Disgeneric marriage?

Two new species of Zetzellia Oudemans, Z. agistzellia sp. n. and Z. quasagistemas sp. n., are described from rubber trees of northwestern São Paulo State, Brazil. Females have clear features of Zetzellia, whereas males resemble Agistemus in some characters. Immatures are also described. The discovery of these species raises some problems concerning generic concepts in Stigmaeidae. Since features of different genera are present in the same species, the authors suggest that the scope of those genera should be reviewed. Copyright © 2005 Magnolia Press.

Branchial vascular pathways in two species of Tetraodontiformes and the concept of secondary vessels and nutrient arteries

The vascular organisation of the branchial basket was examined in two Tetraodontiform fishes; the three-barred porcupinefish, Dicotylichthys punctulatus and the banded toadfish, Marylina pleurosticta by scanning electron microscopy of vascular casts and standard histological approaches. In D. punctulatus, interarterial anastomoses (iaas) originated at high densities from the efferent filamental and branchial arteries, subsequently re-anastomosing to form progressively larger secondary vessels. Small branches of this system entered the filament body, where it was interspersed between the intrafilamental vessels. Large-bore secondary vessels ran parallel with the efferent branchial arteries, and were found to constitute an additional arterio-arterial pathway, in that these vessels exited the branchial basket in company with the mandibular, the carotid and the afferent and efferent branchial arteries, from where they gave rise to capillary beds after exit. Secondary vessels were not found to supply filament muscle; rather these tissues were supplied by single specialised vessels running in parallel between the efferent and afferent branchial arteries in both species examined. Although the branchial vascular anatomy was generally fairly similar for the two species examined, iaas were not found to originate from any branchial component in the banded toadfish, M. pleurosticta, which instead showed a moderate frequency of iaas on other vessels in the cephalic region. It is proposed that four independent vascular pathways may be present within the teleostean gill filament, the conventional arterio-arterial pathway across the respiratory lamellae; an arterio-arterial system of secondary vessels supplying the filament and non-branchial tissues; a system of vessels supplying the filament musculature; and the intrafilamental vessels (central venous sinus). The present study demonstrates that phylogenetic differences in the arrangement of the branchial vascular system occur between species of the same taxon.

An Integrated Framework To Improve The Concept Of Resource Specialisation.

Resource specialisation, although a fundamental component of ecological theory, is employed in disparate ways. Most definitions derive from simple counts of resource species. We build on recent advances in ecophylogenetics and null model analysis to propose a concept of specialisation that comprises affinities among resources as well as their co-occurrence with consumers. In the distance-based specialisation index (DSI), specialisation is measured as relatedness (phylogenetic or otherwise) of resources, scaled by the null expectation of random use of locally available resources. Thus, specialists use significantly clustered sets of resources, whereas generalists use over-dispersed resources. Intermediate species are classed as indiscriminate consumers. The effectiveness of this approach was assessed with differentially restricted null models, applied to a data set of 168 herbivorous insect species and their hosts. Incorporation of plant relatedness and relative abundance greatly improved specialisation measures compared to taxon counts or simpler null models, which overestimate the fraction of specialists, a problem compounded by insufficient sampling effort. This framework disambiguates the concept of specialisation with an explicit measure applicable to any mode of affinity among resource classes, and is also linked to ecological and evolutionary processes. This will enable a more rigorous deployment of ecological specialisation in empirical and theoretical studies.

Gastric supply manipulation to modulate ghrelin production and enhance vascularization to the cardia: proof of the concept in a porcine model.

Introduction. Selective embolization of the left-gastric artery (LGA) reduces levels of ghrelin and achieves significant short-term weight loss. However, embolization of the LGA would prevent the performance of bariatric procedures because the high-risk leakage area (gastroesophageal junction [GEJ]) would be devascularized. Aim. To assess an alternative vascular approach to the modulation of ghrelin levels and generate a blood flow manipulation, consequently increasing the vascular supply to the GEJ. Materials and methods. A total of 6 pigs underwent a laparoscopic clipping of the left gastroepiploic artery. Preoperative and postoperative CT angiographies were performed. Ghrelin levels were assessed perioperatively and then once per week for 3 weeks. Reactive oxygen species (ROS; expressed as ROS/mg of dry weight [DW]), mitochondria respiratory rate, and capillary lactates were assessed before and 1 hour after clipping (T0 and T1) and after 3 weeks of survival (T2), on seromuscular biopsies. A celiac trunk angiography was performed at 3 weeks. Results. Mean (±standard deviation) ghrelin levels were significantly reduced 1 hour after clipping (1902 ± 307.8 pg/mL vs 1084 ± 680.0; P = .04) and at 3 weeks (954.5 ± 473.2 pg/mL; P = .01). Mean ROS levels were statistically significantly decreased at the cardia at T2 when compared with T0 (0.018 ± 0.006 mg/DW vs 0.02957 ± 0.0096 mg/DW; P = .01) and T1 (0.0376 ± 0.008mg/DW; P = .007). Capillary lactates were significantly decreased after 3 weeks, and the mitochondria respiratory rate remained constant over time at the cardia and pylorus, showing significant regional differences. Conclusions. Manipulation of the gastric flow targeting the gastroepiploic arcade induces ghrelin reduction. An endovascular approach is currently under evaluation.

The pollutant diethylhexyl phthalate regulates hepatic energy metabolism via species-specific PPARalpha-dependent mechanisms.

Background: The modulation of energetic homeostasis by pollutants has recently emerged as a potential contributor to the onset of metabolic disorders. Diethylhexyl phthalate (DEHP) is a widely used industrial plasticizer to which humans are widely exposed. Phthalates can activate the three peroxisome proliferatoractivated receptor (PPAR) isotypes on cellular models and induce peroxisome proliferation in rodents.Objectives: In this study, we aimed to evaluate the systemic and metabolic consequences of DEHP exposure that have remained so far unexplored and to characterize the underlying molecular mechanisms of action.Methods: As a proof of concept and mechanism, genetically engineered mouse models of PPARs were exposed to high doses of DEHP, followed by metabolic and molecular analyses.Results: DEHP-treated mice were protected from diet-induced obesity via PPARalpha-dependent activation of hepatic fatty acid catabolism, whereas the activity of neither PPARbeta nor PPARgamma was affected. However, the lean phenotype observed in response to DEHP in wild-type mice was surprisingly abolished in PPARalpha-humanized mice. These species differences are associated with a different pattern of coregulator recruitment.Conclusion: These results demonstrate that DEHP exerts species-specific metabolic actions that rely to a large extent on PPARalpha signaling and highlight the metabolic importance of the species-specific activation of PPARalpha by xenobiotic compounds. Editor's SummaryDiethylhexyl phthalate (DEHP) is an industrial plasticizer used in cosmetics, medical devices, food packaging, and other applications. Evidence that DEHP metabolites can activate peroxisome proliferatoractivated receptors (PPARs) involved in fatty acid oxidation (PPARalpha and PPARbeta) and adiposite function and insulin resistance (PPARgamma) has raised concerns about potential effects of DEHP on metabolic homeostasis. In rodents, PPARalpha activation also induces hepatic peroxisome proliferation, but this response to PPARalpha activation is not observed in humans. Feige et al. (p. 234) evaluated systemic and metabolic consequences of high-dose oral DEHP in combination with a high-fat diet in wild-type mice and genetically engineered mouse PPAR models. The authors report that mice exposed to DEHP gained less weight than controls, without modifying their feeding behavior; they also exhibited lower triglyceride levels, smaller adipocytes, and improved glucose tolerance compared with controls. These effects, which were observed in mice fed both high-fat and standard diets, appeared to be mediated by PPARalpha-dependent activation of hepatic fatty acid catabolism without apparent involvement of PPARbeta or PPARgamma. However, mouse models that expressed human (versus mouse) PPARalpha tended to gain more weight on a high-fat diet than their DHEP-unexposed counterparts. The authors conclude that findings support species-specific metabolic effects of DEHP mediated by PPARalpha activation.

Immunoscintigraphic localization of inflammatory lesions: concept, radiolabelling and in vitro testing of a granulocyte specific antibody.

Current nuclear medicine techniques for the localization of inflammatory processes are based on injection of 111In labelled autologous granulocytes which need to be isolated and radiolabelled in vitro before reinjection. A new technique is presented here that obviates the need for cell isolation by the direct intravenous injection of a granulocyte specific 123I labelled monoclonal antibody. In this publication the basic parameters of the antibody granulocyte interaction are described. Antibody binding does not inhibit vital functions of the granulocytes, such as chemotaxis and superoxide generation. Scatchard analysis of binding data reveals an apparent affinity of the antibody for granulocytes of 6.8 X 10(9) l/mol and approximately 7.1 X 10(4) binding sites per cell. Due to the high specificity of the antibody, the only expected interference is from CEA producing tumors.

Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept

Epigean ant communities in Atlantic Forest remnants of São Paulo: a comparative study using the guild concept. The guilds constitute a valuable ecological tool, because they allow conducting comparisons among environments under different conditions. The ants can be used as ecological indicators, mainly for the monitoring of degraded forest areas. The aim of this research was to study guild organization among the epigeous Formicidae living in Atlantic forest remnants of the State of São Paulo, Brazil. Ant collections were performed in three distinct Atlantic forest biome areas: arboreal littoral vegetation ("restinga") (Cananéia), semideciduous seasonal forest (Piracicaba) and dense ombrophylousforest (Pariquera-Açu). After identification, the ants were grouped into guilds, based on the ecological attributes of behavior and habit, according to the literature. Nine guilds were found; the semideciduous seasonal forest ecosystem presented eight of them, followed by the arboreal sandbank (7) and dense ombrophylous forest (6). The guilds found were: litter omnivorous and scavengers, granivorous species, specialist predators living in litter and soil, litter generalist predators, subterranean mealybug-dependent species, army ants, dominant or subdominants arboreal, that occasionally forage on the ground, soil or litter dominant and fungus-growers, using feces and insect body fragments. The guilds found can be used in the monitoring of the mirmecofauna in the Atlantic Forest biome, supplying insights for further ecological studies.

Five (or so) challenges for species distribution modelling

Species distribution modelling is central to both fundamental and applied research in biogeography. Despite widespread use of models, there are still important conceptual ambiguities as well as biotic and algorithmic uncertainties that need to be investigated in order to increase confidence in model results. We identify and discuss five areas of enquiry that are of high importance for species distribution modelling: (1) clarification of the niche concept; (2) improved designs for sampling data for building models; (3) improved parameterization; (4) improved model selection and predictor contribution; and (5) improved model evaluation. The challenges discussed in this essay do not preclude the need for developments of other areas of research in this field. However, they are critical for allowing the science of species distribution modelling to move forward.

Isothermal microcalorimetry: a novel method for real-time determination of antifungal susceptibility of Aspergillus species.

We evaluated microcalorimetry for real-time susceptibility testing of Aspergillus spp. based on growth-related heat production. The minimal heat inhibitory concentration (MHIC) for A. fumigatus ATCC 204305 was 1 mg/L for amphotericin B, 0.25 mg/L for voriconazole, 0.06 mg/L for posaconazole, 0.125 mg/L for caspofungin and 0.03 mg/L for anidulafungin. Agreement within two 2-fold dilutions between MHIC (determined by microcalorimetry) and MIC or MEC (determined by CLSI M38A) was 90% for amphotericin B, 100% for voriconazole, 90% for posaconazole and 70% for caspofungin. This proof-of-concept study demonstrated the potential of isothermal microcalorimetry for growth evaluation of Aspergillus spp. and real-time antifungal susceptibility testing.