Mineralogy and trace-element geochemistry of the high-grade iron ores of the Aguas Claras Mine and comparison with the Capao Xavier and Tamandua iron ore deposits, Quadrilahero Ferrifero, Brazil

Several major iron deposits occur in the Quadrilatero Ferrifero (QF), southeastern region of Brazil, where metamorphosed and heterogeneously deformed banded iron formation (BIF) of the Caue Formation, regionally called itabirite, was transformed into high- (Fe >64%) and lowgrade (30%Tamandua orebodies shows that the original composition of the itabiritic protore plays a major role in the genesis of high- and low-grade soft ores in the QF. Under the same weathering and structural conditions, the dolomitic itabirite is the more favorable to form high-grade deposits than siliceous itabirite. Field relations at the Aguas Claras and Capao Xavier deposits suggest that it is not possible to form huge soft high-grade supergene deposits from siliceous itabirite, unless another control, such as impermeable barriers, had played an important role. The occurrence in the Tamandua Mine of a large, soft, high-grade orebody formed from siliceous itabirite and closely associated with hypogene hard ore suggests that large, soft, high-grade orebodies of the Quadrilatero Ferrifero, which occur within siliceous itabirite, have a hypogene contribution in their formation.

Vertebral spine of Tamandu-mirim Tamandua tetradactyla

Anatomical studies of the anteater (Tamandua tetradactyla) are scarce and the articles that describe the vertebral column of this species have variations in the number of thoracic and lumbar vertebrae. This study had the objective of adding data to the existing literature about the anatomical composition of an anteater's vertebral column using radiographic and tomographic exams. Based on the cadaver of a young female anteater, we observed a total of 7 cervical, 16 thoracic, 3 lumbar and 5 sacral vertebrae, which differed from the cited literature, especially with respect to the thoracic vertebrae. This demonstrates the need for studies with a larger number of individuals in order to standardize possible anatomic variations for the species.

Placentation in the anteaters Myrmecophaga tridactyla and Tamandua tetradactyla (Eutheria, Xenarthra)

Background: Since Xenarthra are serious candidates for being basal to Eutheria, their characteristics, e.g. the placental system, influence perceptions of evolution. However, in the subgroup containing the anteaters, data are very limited. The present study aims to elucidate the nature of the feto-maternal interface in the anteater placenta and to interpret these data within an evolutionary context. Methods: Placentas of two species were investigated with histology, immunohistochemistry and transmission electron microscopy. Results: Remnants of the maternal vessel endothelium were absent, resulting in a fully haemochorial barrier throughout the placenta. Two structurally different parts, the villous and trabecular areas were complex and intermingled. In particular, the trabeculae which consisted of cellular, proliferative trophoblast, associated with connective tissue, were attached to the decidua. The villi contained fetal capillaries and hypertrophied mesenchymal cells that occured near the surface near the end of gestation. The surface of the villi consisted of flat, syncytial trophoblast, interspersed with proliferative trophoblast cells. Conclusions: Based on fundamental differences between anteaters and armadillos, we inferred that placental evolution was more complex than previously thought. The haemochorial pattern of anteaters was likely an ancient condition of xenarthrans. Consequently, villous placentation may be attributed, at least in part, by convergent evolution, but was also characterized by some features that were widespread among xenarthrans.

Chromosome study of Anteaters (Myrmecophagideae, Xenarthra): a preliminary report

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Importance of xenarthrans in the eco-epidemiology of Paracoccidioides brasiliensis

Background. Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Latin America. Findings. This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla), by molecular and mycological approaches, in samples obtained by one of the following strategies: i) from road-killed animals (n = 6); ii) from naturally dead animals (n = 8); iii) from animals that died in captivity (n = 9); and iv) from living animals captured from the wild (n = 2). Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus) and in 2/2 anteaters (M. tridactyla). The fungus was also cultured in tissue samples from one of two armadillos captured from the wild. Conclusion. Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment. © 2009 Bagagli et al; licensee BioMed Central Ltd.

Evolução cromossômica na Ordem Xenarthra

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Phylogenetic analysis of 16S mitochondrial DNA data in sloths and anteaters

We sequenced part of the 16S rRNA mitochondrial gene in 17 extant taxa of Pilosa (sloths and anteaters) and used these sequences along with GenBank sequences of both extant and extinct sloths to perform phylogenetic analysis based on parsimony, maximum-likelihood and Bayesian methods. By increasing the taxa density for anteaters and sloths we were able to clarify some points of the Pilosa phylogenetic tree. Our mitochondrial 16S results show Bradypodidae as a monophyletic and robustly supported clade in all the analysis. However, the Pleistocene fossil Mylodon darwinii does not group significantly to either Bradypodidae or Megalonychidae which indicates that trichotomy best represents the relationship between the families Mylodontidae, Bradypodidae and Megalonychidae. Divergence times also allowed us to discuss the taxonomic status of Cyclopes and the three species of three-toed sloths, Bradypus tridactylus, Bradypus variegatus and Bradypus torquatus. In the Bradypodidae the split between Bradypus torquatus and the proto-Bradypus tridactylus / B. variegatus was estimated as about 7.7 million years ago (MYA), while in the Myrmecophagidae the first offshoot was Cyclopes at about 31.8 MYA followed by the split between Myrmecophaga and Tamandua at 12.9 MYA. We estimate the split between sloths and anteaters to have occurred at about 37 MYA.

Caracterização morfológica, química e conservação in vitro de Pfaffia glomerata(Sprengel)Pedersen

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morfologia funcional e desenho corporal da cintura pélvica e membros posteriores dos Tamanduás (Mammalia : Xenarthra : Myrmecophagidae)

Entre os mamíferos, os xenartros são, sem dúvida alguma um grupo bastante singular no que diz respeito à morfologia, fisiologia e hábitos locomotores e alimentares. Dentro da ordem Xenarthra, a família Myrmecophagidae é a que tem recebido nos últimos anos, menos atenção em termos de trabalhos sobre morfologia funcional e biomecânica, em especial dos membros posteriores. Visando contribuir para o enriquecimento do conhecimento biológico acerca da natureza morfofuncional e biomecânica dos membros posteriores (fêmur e tíbia) e cintura pélvica destes animais [gêneros Cyclopes (tamanduaí), Tamandua (tamanduá-de-colete) e Myrmecophaga (tamanduá-bandeira)], este trabalho propõe um estudo osteológico descritivo-comparativo destas estruturas, enfatizando os principais pontos com reflexo na funcionalidade biomecânica ligada aos hábitos locomotores. Para isso, além das descrições osteológicas, foram tomadas vinte e três medidas pós-cranianas distribuídas entre a cintura pélvica, fêmur, tíbia, úmero e rádio. A partir de tais medidas, foram calculados treze índices osteométricos, os quais provaram ser eficazes na caracterização morfofuncional dos três gêneros mirmecofagídeos, além de separá-los biomecanicamente em seus estilos locomotores.

Filogenia molecular dos xenarthra (Mammalia): análise do grupo cingulata a partir de sequências nucleotídicas do gene mitocondrial rRNA 16S

Os Xenarthra são o grupo de mamíferos que inclui os tatus, os tamanduás e as preguiças. A América do Sul serviu de cenário para a história natural do grupo que, somente no fim do Cenozóico, dispersou-se para a América Central e, com uma perda de variedade, chegou à América do Norte e à algu-mas ilhas do Caribe. Trinta e uma espécies estão descritas dentro da linha-gem dos Xenarthra. Elas estão classificadas em 13 gêneros, quatro famílias (Bradypodidae, Megalonychidae, Myrmecophagidae e Dasypodidae) e duas ordens (Cingulata e Pilosa). A filogenia deste grupo tem sido alvo de diver-sas pesquisas que analisaram tanto dados morfológicos, quanto moleculares. Delsuc et al. (2003) analisaram seqüências de genes mitocondriais e nucleares e confirmaram a monofilia das três subfamílias (Dasypodinae, Euphacti-nae e Tolypeutinae) inclusas na família Dasypodidae. Delsuc et al. (2003) geraram a seguinte árvore: (((Bradypus, Choloepus)100, ((Myrmecophaga, Tamandua)100, Cyclopes)100), ((D. kappleri, D. novemcinctus)100, (Toly-pentes, (Priodontes, Cabassous)54)100, (Zaedyus, (Euphractus, Chaetophrac-tus)60)100)). Gaudin (2005) apresentou um trabalho que reviu e ampliou as análises morfológicas apresentadas até então, concluindo que os tatus atu-ais estão divididos em dois grupos, um mais basal (Dasypodinae) e outro mais derivado (Euphractinae), de acordo com o seguinte arranjo: (Bradypus, Tamandua), (Dasypus, (Priodontes, (Cabassous, (Tolypeutes, (Euphractus, Chaetophractus, (Zaedyus, Chlamyphorus)42)36)72)72)40)85). Neste traba-lho utilizou-se parte do gene mitocondrial rRNA 16S de 12 táxons atu-ais de Xenarthra para analisar a filogenia do grupo através do critério de máxima verossimilhança. Nossos resultados são apresentados analisando-se o gene 16S e analisando o banco de dados do 16S mais o de Delsuc et al. (2003). Nas duas situações, as filogenias apresentadas apóiam os resulta-dos de Delsuc et al. (2003): (Bradypus, (Choloepus, ((Cyclopes, (Myrme-cophaga, Tamandua)100)100, (Dasypus, (((Cabassous, Priodontes)68, Toly-peutes)100,((Chaetophractus, Euphractus)65, Zaedyus)100)100)100)100)100). Uma melhora nos valores de bootstrap nos ramos dentro das sub-famílias da família Dasypodidae é percebida em relação ao trabalho de Delsuc et al. (2003). Acreditamos que Elementos de Transposição do tipo (LINES) são os marcadores moleculares mais adequados para confirmar o arranjo obtido com as seqüências de genes mitocondriais e nucleares.

Levantamento rápido de mamíferos terrestres de médio e grande porte no Parque Natural Municipal Cachoeira da Marta, Botucatu/SP

One of the most important strategies for biodiversity conservation is the establishment of protected areas, which protect areas important for the survival of several species. The park “Parque Natural Municipal Cachoeira da Marta”, located in Botucatu, São Paulo, is a unit of strictly protected area and aims to conserve the ecosystems and the biodiversity that exists in the area. The park has a management plan, but this does not include a survey of mammals present in the area, which is relevant as the group has a high degree of threat and a huge ecological importance. Thus, this study aimed to conduct a quick survey of terrestrial mammals of medium and large through the methodology of sand plots, with 25 plots distributed in five areas throughout the park. We recorded 4 orders, 6 families and 9 species (Nasua Nasua, Eira Barbara, Procyon cancrivorous, Leopardus pardalis, Leopardus sp., Dasypus novemcinctus, Tamandua tetradctyla, and Cavia aperea Myrmecophaga tridactyla). Most animals marked are generalist feeding habits, but it was also reported the presence of species more demanding regarding the quality of the habitat

Molecular detection of Leishmania spp. in road-killed wild mammals in the Central Western area of the State of São Paulo, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Rickettsial Infection in Ticks Collected from Road-Killed Wild Animals in Rio de Janeiro, Brazil

During 2008D2010, ticks were collected from road-killed wild animals within the Serra dos Orgaos National Park area in the state of Rio de Janeiro, Brazil. In total, 193 tick specimens were collected, including Amblyomma dubitatum Neumann and Amblyomma cajennense (F.) from four Hydrochoerus hydrochaeris (L.), Amblyomma calcaratum Neumann and A. cajennense from four Tamandua tetradactyla (L.), Amblyomma aureolatum (Pallas) and A. cajennense from five Cerdocyon thous L., Amblyomma longirostre (Koch) from one Sphiggurus villosus (Cuvier), Amblyomma varium Koch from three Bradypus variegatus Schinz, and A. cajennense from one Buteogallus meridionalis (Latham). Molecular analyses based on polymerase chain reaction targeting two rickettsial genes (gltA and ompA) on tick DNA extracts showed that 70.6% (12/17) of the A. dubitatum adult ticks, and all Amblyomma sp. nymphal pools collected from capybaras were shown to contain rickettsial DNA, which after DNA sequencing, revealed to be 100% identical to the recently identified Rickettsia sp. strain Pampulha from A. dubitatum ticks collected in the state of Minas Gerais, Brazil. Phylogenetic analysis with concatenated sequences (gltA-ompA) showed that our sequence from A. dubitatum ticks, referred to Rickettsia sp. strain Serra dos Orgaos, segregated under 99% bootstrap support in a same cluster with Old World rickettsiae, namely R. tamurae, R. monacensis, and Rickettsia sp. strain 774e. Because A. dubitatum is known to bite humans, the potential role of Rickettsia sp. strain Serra dos Orgaos as human pathogen must be taken into account, because both R. tamurae and R. monacencis have been reported infecting human beings.

Importance of xenarthrans in the eco-epidemiology of Paracoccidioides brasiliensis

Abstract Background Several pathogens that cause important zoonotic diseases have been frequently associated with armadillos and other xenarthrans. This mammal group typically has evolved on the South American continent and many of its extant species are seriously threatened with extinction. Natural infection of armadillos with Paracoccidioides brasiliensis in hyperendemic areas has provided a valuable opportunity for understanding the role of this mammal in the eco-epidemiology of Paracoccidioidomycosis (PCM), one of the most important systemic mycoses in Latin America. Findings This study aimed to detect P. brasiliensis in different xenarthran species (Dasypus novemcinctus, Cabassous spp., Euphractus sexcinctus, Tamandua tetradactyla and Myrmecophaga tridactyla), by molecular and mycological approaches, in samples obtained by one of the following strategies: i) from road-killed animals (n = 6); ii) from naturally dead animals (n = 8); iii) from animals that died in captivity (n = 9); and iv) from living animals captured from the wild (n = 2). Specific P. brasiliensis DNA was detected in several organs among 7/20 nine-banded armadillos (D. novemcinctus) and in 2/2 anteaters (M. tridactyla). The fungus was also cultured in tissue samples from one of two armadillos captured from the wild. Conclusion Members of the Xenarthra Order, especially armadillos, have some characteristics, including a weak cellular immune response and low body temperature, which make them suitable models for studying host-pathogen interaction. P. brasiliensis infection in wild animals, from PCM endemic areas, may be more common than initially postulated and reinforces the use of these animals as sentinels for the pathogen in the environment.

Comparative histology of the adult electric organ among four species of the genus Campylomormyrus (Teleostei: Mormyridae)

The electric organ (EO) of weakly electric mormyrids consists of flat, disk-shaped electrocytes with distinct anterior and posterior faces. There are multiple species-characteristic patterns in the geometry of the electrocytes and their innervation. To further correlate electric organ discharge (EOD) with EO anatomy, we examined four species of the mormyrid genus Campylomormyrus possessing clearly distinct EODs. In C. compressirostris, C. numenius, and C. tshokwe, all of which display biphasic EODs, the posterior face of the electrocytes forms evaginations merging to a stalk system receiving the innervation. In C. tamandua that emits a triphasic EOD, the small stalks of the electrocyte penetrate the electrocyte anteriorly before merging on the anterior side to receive the innervation. Additional differences in electrocyte anatomy among the former three species with the same EO geometry could be associated with further characteristics of their EODs. Furthermore, in C. numenius, ontogenetic changes in EO anatomy correlate with profound changes in the EOD. In the juvenile the anterior face of the electrocyte is smooth, whereas in the adult it exhibits pronounced surface foldings. This anatomical difference, together with disparities in the degree of stalk furcation, probably contributes to the about 12 times longer EOD in the adult.