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Distribuição da família Didelphidae (Mammalia, Didelphimorphia) no Rio Grande do Sul, Brasil; Distribution of didelphidae family (Mammalia, Didelphimorphia) in Rio Grande do Sul, Brazil

Ávila, Maurício Cendon do Nascimento
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Trabalho de Conclusão de Curso Formato: application/pdf
POR
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27.5%
Os marsupiais são um importante componente da fauna de mamíferos sul-americanos e suas adaptações a diversos tipos de hábitat lhes permitiram ocupar diferentes nichos ecológicos. A família Didelphidae é a única família pertencente à ordem Didelphimorphia e compreende a maioria das espécies viventes de marsupiais americanos. Atualmente a família inclui 95 espécies reconhecidas, distribuídas em 19 gêneros recentes, das quais somente quatro não ocorrem na América do Sul. A sua distribuição é ampla e ocorre naturalmente do sudeste do Canadá até o sul da Argentina. As espécies ocupam todos os grandes biomas e quase todos os tipos de hábitats dentro deles com exceção de altitudes muito elevadas e das regiões extremamente desertificadas. No Brasil ocorrem 55 espécies de marsupiais da família Didelphidae divididas em quatro subfamílias, Glironiinae, Caluromyniae, Hyladelphinae e Didelphinae, distribuídas em 16 gêneros, das quais possivelmente 14 espécies ocorrem no Rio Grande do Sul. Ainda existem lacunas no que diz respeito à distribuição e taxonomia de muitas espécies de marsupiais e a falta de estudos focando esse grupo no extremo sul do Brasil dificulta ainda mais a compreensão da sua diversidade nessa região. Neste contexto...

Padrões de uso do espaço em multiplas escalas por roedores e marsupiais de Mata Atlantica; Multi-scale patterns of space use by rodents and marsupials in the atlantic forest

Natalia Oliveira Leiner
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/05/2009 PT
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Diversos fatores influenciam os padrões de uso de espaço de pequenos mamíferos, tais como estrutura de hábitat, riscos de predação e período reprodutivo. O objetivo desse estudo foi investigar a influência de tais fatores sobre o uso de espaço de roedores e marsupiais em diferentes escalas. No primeiro capítulo, analisamos a estrutura das comunidades de pequenos mamíferos não-voadores que ocorrem em fragmentos florestais e em áreas em restauração, e investigamos quais componentes do hábitat influenciam a composição de espécies dessas comunidades. De forma geral, os resultados mostraram que a composição de espécies é um reflexo das preferências que as espécies apresentam por determinados componentes do hábitat, de forma que características estruturais da vegetação e sensibilidade das espécies às alterações determinam a estrutura das comunidades de pequenos mamíferos nos hábitats amostrados. No segundo capítulo, testamos a hipótese de que a importância de diferentes fatores na seleção de hábitats por Marmosops incanus e Marmosops paulensis depende da escala de observação, e a hipótese de que o uso de hábitat funciona como um mecanismo para garantir a coexistência dessas duas espécies, de forma que essas espécies devem selecionar diferentes componentes do hábitat e/ou apresentar segregação no uso vertical do espaço. Os resultados demonstraram que ambas as espécies selecionam os fragmentos florestais pela presença de maior complexidade estrutural e sub-bosque denso...

Didelphidae marsupials (Mammalia, Didelphimorphia) from the Late Pleistocene deposit of the Gruta dos Moura Cave, northern Brazil

Nova,Patricia Villa; Avilla,Leonardo S.; Oliveira,Édison V.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2015 EN
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The present study acknowledges the diversity of fossil marsupials from the Gruta dos Moura cave, as well as environmental and climatic aspects during the Quaternary. The results show that this is the largest diversity of Pleistocene marsupials recorded in a single cave: Didelphis albiventris, D. aurita, Gracilinanus agilis, G. microtarsus, Marmosa murina, Monodelphis brevicaudata, M. domestica and Sairadelphys tocantinensis. Furthermore, the described specimens are also part of the only fossil assemblage unequivocally referable to the late Pleistocene. Paleontological studies suggest an intimate association with dry and open environments with high abundance of water sources. Since most of the identified taxa are characteristic of open forests and gallery forests, this could represent the actual environment around the Gruta dos Moura cave. Recent studies identified sympatric occurrences between species from open and dry environments and species from humid forests that were identified among our material and are characteristic of humid regions. Therefore, these species could inhabit gallery forests and capons, or even ecotones, inside a dry and open environment. Moreover, the extinction of Sairadelphys could also indicate that the climatic and environmental conditions changed or that the past environment was more heterogeneous than the current environment of the region.

Siphonaptera parasites of wild rodents and marsupials trapped in three mountain ranges of the Atlantic Forest in Southeastern Brazil

Moraes,Leandro Bianco de; Bossi,David Eduardo Paolinetti; Linhares,Arício Xavier
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2003 EN
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A study of the associations between small mammals and fleas was undertaken in three areas of the Atlantic Forest in Souhtheastern Brazil: Serra da Fartura, SP, Serra da Bocaina, SP, and Itatiaia, RJ. Trapping of small rodents and marsupials was done every 3 months during 2 years, from June 1999 to May 2001. A total 502 rodents (13 species) and 50 marsupials (7 species) were collected, and 185 hosts out of 552 (33.5%) captured in the traps were parasitized by 327 fleas belonging to 11 different species. New host records were determined for several flea species, and 5 significant associations between fleas and hosts were also found.

American marsupials chromosomes: why study them?

Svartman,Marta
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2009 EN
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37.44%
Marsupials, one of the three main groups of mammals, are only found in Australia and in the American continent. Studies performed in Australian marsupials have demonstrated the great potential provided by the group for the understanding of basic genetic mechanisms and chromosome evolution in mammals. Genetic studies in American marsupials are relatively scarce and cytogenetic data of most species are restricted to karyotype descriptions, usually without banding patterns. Nevertheless, the first marsupial genome sequenced was that of Monodelphis domestica, a South American species. The knowledge about mammalian genome evolution and function that resulted from studies on M. domestica is in sharp contrast with the lack of genetic data on most American marsupial species. Here, we present an overview of the chromosome studies performed in marsupials with emphasis on the South American species.

Diversity of Color Vision: Not All Australian Marsupials Are Trichromatic

Ebeling, Wiebke; Natoli, Riccardo C.; Hemmi, Jan M.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 06/12/2010 EN
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Color vision in marsupials has recently emerged as a particularly interesting case among mammals. It appears that there are both dichromats and trichromats among closely related species. In contrast to primates, marsupials seem to have evolved a different type of trichromacy that is not linked to the X-chromosome. Based on microspectrophotometry and retinal whole-mount immunohistochemistry, four trichromatic marsupial species have been described: quokka, quenda, honey possum, and fat-tailed dunnart. It has, however, been impossible to identify the photopigment of the third cone type, and genetically, all evidence so far suggests that all marsupials are dichromatic. The tammar wallaby is the only Australian marsupial to date for which there is no evidence of a third cone type. To clarify whether the wallaby is indeed a dichromat or trichromatic like other Australian marsupials, we analyzed the number of cone types in the “dichromatic” wallaby and the “trichromatic” dunnart. Employing identical immunohistochemical protocols, we confirmed that the wallaby has only two cone types, whereas 20–25% of cones remained unlabeled by S- and LM-opsin antibodies in the dunnart retina. In addition, we found no evidence to support the hypothesis that the rod photopigment (rod opsin) is expressed in cones which would have explained the absence of a third cone opsin gene. Our study is the first comprehensive and quantitative account of color vision in Australian marsupials where we now know that an unexpected diversity of different color vision systems appears to have evolved.

American marsupials chromosomes: Why study them?

Svartman, Marta
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.36%
Marsupials, one of the three main groups of mammals, are only found in Australia and in the American continent. Studies performed in Australian marsupials have demonstrated the great potential provided by the group for the understanding of basic genetic mechanisms and chromosome evolution in mammals. Genetic studies in American marsupials are relatively scarce and cytogenetic data of most species are restricted to karyotype descriptions, usually without banding patterns. Nevertheless, the first marsupial genome sequenced was that of Monodelphis domestica, a South American species. The knowledge about mammalian genome evolution and function that resulted from studies on M. domestica is in sharp contrast with the lack of genetic data on most American marsupial species. Here, we present an overview of the chromosome studies performed in marsupials with emphasis on the South American species.

Artificial insemination in marsupials

Rodger, J.; Paris, D.; Czarny, N.; Harris, M.; Molinia, F.; Taggart, D.; Allen, C.; Johnston, S.
Fonte: Elsevier Science Inc Publicador: Elsevier Science Inc
Tipo: Artigo de Revista Científica
Publicado em //2009 EN
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27.44%
Assisted breeding technology (ART), including artificial insemination (AI), has the potential to advance the conservation and welfare of marsupials. Many of the challenges facing AI and ART for marsupials are shared with other wild species. However, the marsupial mode of reproduction and development also poses unique challenges and opportunities. For the vast majority of marsupials, there is a dearth of knowledge regarding basic reproductive biology to guide an AI strategy. For threatened or endangered species, only the most basic reproductive information is available in most cases, if at all. Artificial insemination has been used to produce viable young in two marsupial species, the koala and tammar wallaby. However, in these species the timing of ovulation can be predicted with considerably more confidence than in any other marsupial. In a limited number of other marsupials, such precise timing of ovulation has only been achieved using hormonal treatment leading to conception but not live young. A unique marsupial ART strategy which has been shown to have promise is cross-fostering; the transfer of pouch young of a threatened species to the pouches of foster mothers of a common related species as a means to increase productivity. For the foreseeable future...

Molecular insights into xenobiotic disposition in Australian marsupials

El-Merhibi, A.; Ngo, S.; Jones, B.; Milic, N.; Stupans, I.; McKinnon, R.
Fonte: Australasian Society for Ecotoxicology Publicador: Australasian Society for Ecotoxicology
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
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During the past two decades, studies of xenobiotic detoxification by molecular biology in diverse organisms have identified many novel environmental adaptations, providing valuable insight into habitat, dietary preferences and general physiology. While xenobiotic detoxification has been extensively studied in eutherian mammals, metabolic data concerning detoxification in Australian marsupials are limited, particularly at the molecular level of the enzymes involved. At present Australia relies heavily on overseas data to determine the possible outcomes of xenobiotic exposure in Australian native fauna. Unlike eutherian mammals, many marsupial herbivores ingest and absorb large amounts of dietary Eucalyptus terpenes. Such quantities would be toxic, even potentially fatal, to human and many other mammalian species. Specialist Eucalyptus herbivores, such as koalas and brushtail possums, have been hypothesised to utilise highly efficient enzyme systems to metabolise terpenes to non-toxic substances that can be readily excreted in the urine. Enzymes that carry out the biotransformation of Eucalyptus terpenes have been partially identified to be the cytochromes P450 (CYP). The aim of this review is to provide a summary of work being undertaken over several years in our laboratories that has provided unique insights into marsupial biology. The focuses of this study are phase I and phase II metabolisms in these unique animals...

Cytochrome P450 CYP3A in marsupials: Cloning and characterisation of the second identified CYP3A subfamily member, isoform 3A78 from koala (Phascolarctos cinereus)

El-Merhibi, A.; Ngo, S.; Crittenden, T.; Marchant, C.; Stupans, I.; McKinnon, R.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2011 EN
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27.44%
Cytochromes P450 (CYPs) are critically important in the oxidative metabolism of a diverse array of xenobiotics and endogenous substrates. Previously, we cloned and characterised the CYP2C, CYP4A, and CYP4B gene subfamilies from marsupials and demonstrated important species-differences in both activity and tissue expression of these CYP enzymes. Recently, we isolated the Eastern grey kangaroo CYP3A70. Here we have cloned and characterised the second identified member of marsupial CYP3A gene subfamily, CYP3A78 from the koala (Phascolarctos cinereus). In addition, we have examined the gender-differences in microsomal erythromycin N-demethylation activity (a CYP3A marker) and CYP3A protein expression across test marsupial species. Significant differences in hepatic erythromycin N-demethylation activity were observed between male and female koalas, with the activity detected in female koalas being 2.5-fold higher compared to that in male koalas (p<0.01). No gender-differences were observed in tammar wallaby or Eastern grey kangaroo. Immunoblot analysis utilising anti-human CYP3A4 antibody detected immunoreactive proteins in liver microsomes from all test male and female marsupials including the koala, tammar wallaby, and Eastern grey kangaroo...

Cytochrome P450 CYP3A in marsupials: cloning and identification of the first CYP3A subfamily member, isoform 3A70 from Eastern gray kangaroo (Macropus giganteus)

El-Merhibi, A.; Ngo, S.; Marchant, C.; Height, T.; Stupans, I.; McKinnon, R.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
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27.36%
Australian marsupials are unique fauna that have evolved and adapted to unique environments and thus it is likely that their detoxification systems differ considerably from those of well-studied eutherian mammals. Knowledge of these processes in marsupials is therefore vital to understanding the consequences of exposure to xenobiotics. Cytochromes P450 (CYPs) are critically important in the oxidative metabolism of a diverse array of both xenobiotics and endogenous substrates. In this study we have cloned and characterized CYP3A70, the first identified member of the CYP3A gene subfamily from Eastern gray kangaroo (Macropus giganteus). A 1665 base pair kangaroo hepatic CYP3A complete cDNA, designated CYP3A70, was cloned by reverse transcription-polymerase chain reaction approaches, which encodes a protein of 506 amino acids. The CYP3A70 cDNA shares approximately 71% nucleotide and 65% amino acid sequence homology to human CYP3A4 and displays high sequence similarity to other published mammalian CYP3As from human, monkey, cow, pig, dog, rat, rabbit, mouse, hamster, and guinea pig. Transfection of the CYP3A70 cDNAs into 293T cells resulted in stable cell lines expressing a CYP3A immuno-reactive protein that was recognized by a goat anti-human CYP3A4 polyclonal antibody. The anti-human CYP3A4 antibody also detected immunoreactive proteins in liver microsomes from all test marsupials...

Scaling of cerebral blood perfusion in primates and marsupials

Seymour, R.S.; Angove, S.E.; Snelling, E.P.; Cassey, P.
Fonte: Company of Biologists Publicador: Company of Biologists
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
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27.36%
The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys...

The development of the olfactory organs in newly hatched monotremes and neonate marsupials

Schneider, Nanette Yvette
Fonte: Blackwell Science Inc Publicador: Blackwell Science Inc
Tipo: Artigo de Revista Científica
EN
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27.44%
Olfactory cues are thought to play a crucial role in the detection of the milk source at birth in mammals. It has been shown that a marsupial, the tammar wallaby, can detect olfactory cues from its mother's pouch at birth. This study investigates whether the main olfactory and accessory olfactory system are similarly well developed in other marsupials and monotremes at birth/hatching as in the tammar. Sections of the head of various marsupial and two monotreme species were investigated by light microscopy. Both olfactory systems were less well developed in the kowari and Eastern quoll. No olfactory or vomeronasal or terminal nerves could be observed; the main olfactory bulb (MOB) had only two layers while no accessory olfactory bulb or ganglion terminale were visible. All other investigated marsupials and monotremes showed further developed olfactory systems with olfactory, vomeronasal and terminal nerves, a three-layered MOB, and in the marsupials a prominent ganglion terminale. The main olfactory system was further developed than the accessory olfactory system in all species investigated. The olfactory systems were the least developed in species in which the mother's birth position removed most of the difficulty in reaching the teat...

The significance of striated muscle in the mammary glands of marsupials.

Griffiths, M; Slater, E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1988 EN
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The distribution and amounts of striated muscle within the mammary glands of pouched and pouchless marsupials from Australia and South America are described. Invasions into the mammary secretory parenchyma in pouchless marsupials by swathes of striated muscle from the ilio-marsupialis muscle are massive, in some instances concentrated into discrete muscles, which are inserted on to the bases of the teats; the name retractor mammae is proposed for these muscles. In pouched marsupials striated muscle penetrates the parenchyma, but the distribution is diffuse and the muscle strands are not inserted on to teats except in the instance of the glands of the honey possum Tarsipes rostratus. The young of anaesthetised pouchless marsupials hang down from the teats; as anaesthesia wears off they are hauled up tightly into the mammary area. It is concluded that this is a result of contraction of the retractor mammae muscles and that it is a means of protecting the naked young from injury by rough terrain. The mammary gland musculature in pouched marsupials is considered to be vestigial, but its contraction may have the function of initiating a 'tap-response' contraction of myoepithelium acting synergistically with the 'let-down' hormone mesotocin. Mechanisms of imbibition of milk by marsupial neonates...

How forest marsupials are affected by habitat degradation and fragmentation? A meta-analysis

Salazar, Daniela A.; Malebrán, Javiera; Botto Mahan, Carezza Verónica; González Browne, Catalina; Candia, Alina B.; Fontúrbel, Francisco E.
Fonte: Springer Publicador: Springer
Tipo: Artículo de revista
EN
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Artículo de publicación ISI; Habitat fragmentation and degradation are important biodiversity change drivers worldwide. Their effects have been described for many animal groups, but little is known about marsupials. We conducted a meta-analysis aiming to evaluate the actual effects of habitat fragmentation and degradation on forest marsupials. From a literature survey, we obtained 85 case studies reporting disturbance comparisons. We found a negative overall effect, as well as a negative effect for habitat fragmentation, but not for habitat degradation. Marsupials from Oceania were negatively affected by habitat disturbance, whereas there was no effect for those from South America. Arboreal marsupials were negatively affected, whereas terrestrial marsupials did not. Species from the families Dasyuridae (Antechinus spp.) and Microbiotheriidae (Dromiciops gliroides) showed to be sensitive to habitat disturbance.; FONDECYT project 3140528 (FEF)

A survey design for monitoring the abundance if arboreal marsupials in the Central Highlands of Victoria

Lindenmayer, David; Cunningham, Ross; MacGregor, Chris; Incoll, R; Michael, Damian
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
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We describe a non-standard sample design for monitoring the abundance of arboreal marsupials in the montane ash forests of the Central Highlands of Victoria, south-eastern Australia. The survey design is based on overlapping and rotating sampling from a given population of sites - in this case 160 sites, each measuring 1 ha in size. Estimates of population sizes are obtained using a model-based statistical analysis. Results so far reveal considerable year-to-year variability in populations of Leadbeater's Possum (Gymnobelideus leadbeateri), the Mountain Brushtail Possum (Trichosurus cunninghamii), and the Greater Glider (Petauroides volans). There appears to be an initial decline in the numbers of Leadbeater's Possum, an increase in the Mountain Brushtail Possum and no change in the Greater Glider and the total number of arboreal marsupials. It will be possible report more substantive findings about long-term trends after several more years of the program. Relationships between current and past counts for Leadbeater's Possum and Mountain Brushtail Possum were very weak. This result appeared to be due to low levels of site fidelity for these two species.

The response of arboreal Marsupials to landscape context: A large-scale fragmentation study

Lindenmayer, David
Fonte: Ecological Society of America Publicador: Ecological Society of America
Tipo: Artigo de Revista Científica
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37.54%
We describe a landscape-scale study of fragmentation effects on arboreal marsupials at Tumut, southeastern Australia. Embedded within a 55 000-ha plantation of exotic Monterey pine (Pinus radiata) are 192 patches of remnant Eucalyptus forest, with large contiguous areas of eucalypt forest beyond the plantation boundary. We compared presence and estimated abundance of arboreal marsupials in three broad groups of sites: remnants of native Eucalyptus forest in the P. radiata plantation; P. radiata stands in the plantation; and large areas of contiguous Eucalyptus forest surrounding the plantation. The study animals were Trichosurus vulpecula, T. caninus, Petaurus breviceps, P. norfolcensis, P. australis, Acrobates pygmaeus, Pseudocheirus peregrinus, and Petauroides volans. We used randomized, replicated statistical procedures to sample 86 eucalypt remnants varying in size, shape, and other features. We matched 40 sites in large contiguous Eucalyptus forest to those remnants, based on environment, climate, terrain, and vegetation cover. In addition, 40 sites in P. radiata stands were matched to sites in the remnants and the large eucalypt forest on the basis of geology, climate, and terrain. We also surveyed 41 micropatches (remnants < 1 ha)...

Marsupials and monotremes possess a novel family of MHC class I genes that is lost from the eutherian lineage

Papenfuss, Anthony T; Feng, Zhi-Ping; Krasnec, Katina; Deakin, Janine; Baker, Michelle L; Miller, Robert D
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
27.36%
Background: Major histocompatibility complex (MHC) class I genes are found in the genomes of all jawed vertebrates. The evolution of this gene family is closely tied to the evolution of the vertebrate genome. Family members are frequently found in four paralogous regions, which were formed in two rounds of genome duplication in the early vertebrates, but in some species class Is have been subject to additional duplication or translocation, creating additional clusters. The gene family is traditionally grouped into two subtypes: classical MHC class I genes that are usually MHC-linked, highly polymorphic, expressed in a broad range of tissues and present endogenously-derived peptides to cytotoxic T-cells; and non-classical MHC class I genes generally have lower polymorphism, may have tissue-specific expression and have evolved to perform immune-related or non-immune functions. As immune genes can evolve rapidly and are subject to different selection pressure, we hypothesised that there may be divergent, as yet unannotated or uncharacterised class I genes. Results: Application of a novel method of sensitive genome searching of available vertebrate genome sequences revealed a new, extensive sub-family of divergent MHC class I genes, denoted as UT...

Nestedness in fragmented landscapes: a case study on birds, arboreal marsupials and lizards

Fischer, Joern; Lindenmayer, David
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
37.36%
Aim: The potential nestedness of assemblages of birds, arboreal marsupials and lizards was examined in a fragmented landscape in south-eastern Australia. We assessed which ecological processes were related to the presence or absence of nestedness, particularly in relation to previous autoecological studies in the same study area. Location: Data were collected at Buccleuch State Forest, c. 100 km to the west of the Australian Capital Territory in south-eastern Australia. Methods: Presence/absence matrices were compiled for birds (40 pine sites, 40 continuous forest sites, 43 fragments), arboreal marsupials (41 continuous forest sites, 39 fragments) and lizards (30 sites including all landscape elements) from a range of field surveys conducted since 1995. Nestedness was analysed using a standardized discrepancy measure, and statistical significance was assessed using the RANDNEST null model. For birds, species thought to be extinction-prone were analysed separately to assess if assemblages comprising extinction-prone species were more strongly nested than others. Also, sites with a substantial amount of Eucalyptus radiata were analysed separately to assess whether nestedness was stronger if environmental heterogeneity was minimized. Results: The assemblages of lizards and arboreal marsupials were not nested...

Jumping ability in the arboreal locomotion of didelphid marsupials

Delciellos,Ana Cláudia; Vinícius Vieira,Marcus
Fonte: Mastozoología neotropical Publicador: Mastozoología neotropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
27.36%
Didelphid marsupials are considered to cross discontinuities between arboreal supports using a cautious locomotion, using the prehensile tail as fifth limb. However, this ability was only described for Caluromys philander. We describe and compare the locomotory performance and postural behavior of seven species of didelphid marsupials crossing discontinuities between artificial supports representing arboreal gaps. Individuals were captured in areas of Atlantic Forest in Rio de Janeiro State, Brazil. Animals were stimulated to jump from a fixed horizontal support one meter above the ground to an inclined support of same diameter. We measured the maximum distance of jump (40, 60, 80 or 100 cm) and reach or distance actually reached by the jump. Arboreal species (Marmosops incanus, Gracilinanus microtarsus, Micoureus paraguayanus, and C. philander) jumped longer distances and had longer relative reach in jumps than semi-terrestrial species (Didelphis aurita, and Philander frenatus). Only the specialized terrestrial Metachirus nudicaudatus did not jump in the tests. The relation between absolute reach and body size was weak and non significant. This study did not corroborate the view that didelphid marsupials cross discontinuities between arboreal supports only through a cautious locomotion...