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1.
Ecol Appl ; 34(7): e3026, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39192366

RESUMO

Human activities have triggered profound changes in natural landscapes, resulting in species loss and disruption of pivotal ecological interactions such as insect herbivory. This antagonistic interaction is affected by complex pathways (e.g., abundance of herbivores and predators, plant chemical defenses, and resource availability), but the knowledge regarding how forest loss and fragmentation affect insect herbivory in human-modified tropical landscapes still remains poorly understood. In this context, we assessed multi-pathways by which changes in landscape structure likely influence insect herbivory in 20 Atlantic forest fragments in Brazil. Using path analysis, we estimated the direct effects of forest cover and forest edge density, and the indirect effect via canopy openness, number of understory plants and phenolic compounds, on leaf damage in understory plants located in the edge and interior of forest fragments. In particular, plants located in forest edges experienced greater leaf damage than interior ones. We observed that landscape edge density exerted a positive and direct effect on leaf damage in plants sampled at the edge of forest fragments. Our findings also indicated that forest loss and increase of edge density led to an increase in the canopy opening in the forest interior, which causes a reduction in the number of understory plants and, consequently, an increase in leaf damage. In addition, we detected that phenolic compounds negatively influence leaf damage in forest interior plants. Given the increasing forest loss in tropical regions, in which forest fragments become stranded in highly deforested, edge-dominated and degraded landscapes, our study highlights the pervasive enhancement in insect herbivory in remaining forest fragments-especially along forest edges and canopy gaps in the forest interior. As a result, increased herbivory is likely to affect forest regeneration and accelerate the ecological meltdown processes in these highly deforested and disturbed anthropogenic landscapes.


Assuntos
Florestas , Herbivoria , Insetos , Animais , Brasil , Insetos/fisiologia
2.
Conserv Biol ; 38(4): e14250, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38477227

RESUMO

Tropical species richness is threatened by habitat degradation associated with land-use conversion, yet the consequences for functional diversity remain little understood. Progress has been hindered by difficulties in obtaining comprehensive species-level trait information to characterize entire assemblages and insufficient appreciation that increasing land-cover heterogeneity potentially compensates for species loss. We examined the impacts of tropical deforestation associated with land-use heterogeneity on bird species richness, functional redundancy, functional diversity, and associated components (i.e., alpha diversity, species dissimilarity, and interaction strength of the relationship between abundance and functional dissimilarity). We analyzed over 200 georeferenced bird assemblages in the Atlantic Forest of Brazil. We characterized the functional role of the species of each assemblage and modeled biodiversity metrics as a function of forest cover and land-cover heterogeneity. Replacement of native Atlantic Forest with a mosaic of land uses (e.g., agriculture, pastures, and urbanization) reduced bird species richness in a nonrandom way. Core forest species, or species considered sensitive to edges, tended to be absent in communities in heterogenous environments. Overall, functional diversity and functional redundancy of bird species were not affected by forest loss. However, birds in highly heterogenous habitats were functionally distinct from birds in forest, suggesting a shift in community composition toward mosaic-exclusive species led by land-cover heterogeneity. Threatened species of the Atlantic Forest did not seem to tolerate degraded and heterogeneous environments; they remained primarily in areas with large forest tracts. Our results shed light on the complex effects of native forest transformation to mosaics of anthropogenic landscapes and emphasize the importance of considering the effects of deforestation and land-use heterogeneity when assessing deforestation effects on Neotropical biodiversity.


Pérdida de especies y funciones en un bosque tropical megadiverso deforestado Resumen La riqueza de especies tropicales está amenazada por la degradación asociada con la conversión del uso de suelo, y aun así entendemos muy poco de las consecuencias que esto tiene para la diversidad funcional. El progreso está obstaculizado por las dificultades para obtener información completa de los rasgos a nivel de especie para caracterizar ensamblajes completos y la apreciación insuficiente de que la heterogeneidad creciente de la cobertura del suelo tiene el potencial para compensar la pérdida de especies. Analizamos el impacto que tiene la deforestación tropical asociada con la heterogeneidad del uso de suelo sobre la riqueza de especies de aves, la redundancia funcional, la diversidad funcional y sus componentes asociados (es decir, diversidad alfa, disimilitud de especies y fuerza de interacción de la relación entre la abundancia y la disimilitud funcional). Analizamos más de 200 ensamblajes georreferenciados de aves en el Bosque Atlántico de Brasil. Caracterizamos el papel funcional de las especies de cada ensamblaje y modelamos las medidas de biodiversidad como función de la cobertura forestal y de la heterogeneidad del uso de suelo. La sustitución del Bosque Atlántico nativo con un mosaico de usos de suelo (p. ej.: agricultura, pastura y urbanización) redujo la riqueza de especies de una manera no aleatoria. Las especies nucleares del bosque, o las especies consideradas como sensibles a los bordes, tendieron a estar ausentes en las comunidades de los ambientes heterogéneas. En general, la diversidad y la redundancia funcionales de las especies de aves no se vieron afectadas por la pérdida del bosque. Sin embargo, las aves en los hábitats con alta heterogeneidad eran funcionalmente distintas a las aves de los bosques, lo que sugiere un cambio en la composición x de la comunidad hacia especies exclusivas de mosaicos llevadas por la heterogeneidad de la cobertura del suelo. Las especies amenazadas del Bosque Atlántico no parecieron tolerar el ambiente degradado y heterogéneo pues permanecieron principalmente en las áreas con grandes extensiones de bosque. Nuestros resultados arrojan luz sobre los efectos complejos de la transformación de los bosques nativos en mosaicos de paisajes antropogénicos y recalcan la importancia de considerar los efectos de la deforestación y la heterogeneidad del uso de suelo cuando se evalúan los efectos de la deforestación sobre la biodiversidad neotropical.


Assuntos
Biodiversidade , Aves , Conservação dos Recursos Naturais , Florestas , Clima Tropical , Animais , Brasil , Aves/fisiologia
3.
Microb Ecol ; 86(1): 699-712, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35802173

RESUMO

Ants have long been known for their associations with other taxa, including macroscopic fungi and symbiotic bacteria. Recently, many ant species have had the composition and function of their bacterial communities investigated. Due to its behavioral and ecological diversity, the subfamily Ponerinae deserves more attention regarding its associated microbiota. Here, we used the V4 region of the 16S rRNA gene to characterize the bacterial communities of Odontomachus chelifer (ground-nesting) and Odontomachus hastatus (arboreal), two ponerine trap-jaw species commonly found in the Brazilian savanna ("Cerrado") and Atlantic rainforest. We investigated habitat effects (O. chelifer in the Cerrado and the Atlantic rainforest) and species-specific effects (both species in the Atlantic rainforest) on the bacterial communities' structure (composition and abundance) in two different body parts: cuticle and gaster. Bacterial communities differed in all populations studied. Cuticular communities were more diverse, while gaster communities presented variants common to other ants, including Wolbachia and Candidatus Tokpelaia hoelldoblerii. Odontomachus chelifer populations presented different communities in both body parts, highlighting the influence of habitat type. In the Atlantic rainforest, the outcome depended on the body part targeted. Cuticular communities were similar between species, reinforcing the habitat effect on bacterial communities, which are mainly composed of environmentally acquired taxa. Gaster communities, however, differed between the two Odontomachus species, suggesting species-specific effects and selective filters. Unclassified Firmicutes and uncultured Rhizobiales variants are the main components accounting for the observed differences. Our study indicates that both host species and habitat act synergistically, but to different degrees, to shape the bacterial communities in these Odontomachus species.


Assuntos
Formigas , Animais , RNA Ribossômico 16S/genética , Ecossistema , Brasil , Bactérias/genética
4.
Chem Biodivers ; 20(4): e202300021, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36943774

RESUMO

Chemical investigation of the extract of the macroscopic fungus Beenakia informis led to the isolation of a previously unreported γ-pyrone and two new isoprenylated cyclohexanoids, together with speciocin N. Their structures were elucidated spectroscopically and the absolute configuration was determined by comparison of the experimental vs. calculated ECD curves. Three of the compounds showed very good to moderate activity against phytopathogenic fungi.


Assuntos
Antifúngicos , Basidiomycota , Antifúngicos/farmacologia , Antifúngicos/química , Pironas/química , Estrutura Molecular , Fungos
5.
Exp Appl Acarol ; 91(2): 339-358, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37768388

RESUMO

We report Rickettsia species from 2,334 ticks collected from environment (1,939 ticks) and animals (395 ticks) in the largest inland fragment of the Atlantic rainforest of southern Brazil and its fragments. Additionally, the DNA infection rates of Amblyomma ovale tick populations in the Neotropics with Rickettsia bellii and Rickettsia parkeri strain Atlantic rainforest were calculated using data from scientific publications, and their correlation was evaluated. From 11 tick species Rickettsia DNA was detected in seven (Amblyomma brasiliense, Amblyomma coelebs, Amblyomma incisum, Amblyomma longirostre, A. ovale, Haemaphysalis juxtakochi, Ixodes fuscipes) and was not detected in four species (Amblyomma dubitatum, Ixodes loricatus, Rhipicephalus microplus and Rhipicephalus sanguineus sensu lato). DNA of five Rickettsia species was detected (R. bellii, Rickettsia amblyommatis, Rickettsia rhipicephali, Rickettsia felis and Rickettsia sp. Aragaoi). To determine the prevalence of Rickettsia DNA positivity according to vector species, ticks were processed individually or in pools of 2-10 individuals (samples). The most prevalent Rickettsia species was R. bellii, found in 112 samples, followed by R. amblyommatis, R. rhipicephali, R. felis and Rickettsia sp. Aragaoi, found in 16, five, two and one sample, respectively. Rickettsia bellii DNA was found in five tick species with the highest infection rate in A. ovale and A. brasiliense. Absence of R. parkeri strain Atlantic rainforest in A. ovale ticks was an unexpected result. Furthermore, a negative correlation was identified between the infection rates (DNA) of R. bellii and/or R. parkeri strain Atlantic rainforest within A. ovale tick populations in the Neotropics. Putting together current knowledge, it can be proposed that, within natural settings, the diversity of rickettsiae and ticks creates a buffering effect on the overgrowth of rickettsiae and episodes of bacteremia in the hosts.

6.
Plant Dis ; 2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35722917

RESUMO

Cariniana legalis (Mart.) Kuntze (Lecythidaceae), commonly known as "Jequitibá Rosa," an endemic tree from Brazil, is one of the largest trees that grows in the Atlantic Rain Forest. Jequitibá Rosa has been extensively exploited due to the excellent quality of its wood, which has resulted in the species being placed as "vulnerable" on the IUCN red list of threatened species (IUCN, 2021). Thus, conservation of the species is paramount. In October 2018, in the municipality of Ilhéus, Bahia (14º 79' 67" S, 39º 17' 32" W), trees of C. legalis were observed with approximately 80% of leaves presenting light to dark brown necrotic lesions with yellow edges at the tips and margins of the leaves; the lesions gradually expanded through the leaves and coalesced to form wider lesions, which resulted in death of the leaves and weakening of the trees. The symptoms indicate infection caused by a Colletotrichum spp., important pathogens known to cause diseases in several economically important plants. Symptomatic leaves were collected and lesions examined under a stereomicroscope at 20x magnification (Supplementary Figure S1. A). Conidia were transferred directly and aseptically from the leaf spots to potato-dextrose-agar (PDA) and incubated in the dark at 25 ± 1 ºC for 72 h. Subsequently, pure cultures were obtained by monosporic isolation. All fungal structures were measured using a Leica DM500 microscope at 1000x magnification. A pathogenicity test was performed both on hosts in the field and using detached leaves by inoculation with a conidial suspension 106 conidia/mL prepared from a culture grown on PDA incubated in the dark at 25 ± 1 ºC for 10 days. Six healthy and fully developed detached leaves were inoculated with two 10 µL drops of conidial suspension on the adaxial surface. Six leaves were inoculated with two drops of sterile water were used as controls. The inoculated leaves were kept in a humid chamber at 25º C with a 12 h photoperiod. Four trees of C. legalis growing in the field were selected and 120 healthy leaves (30 per tree) sprayed with a conidial suspension and covered with transparent polyethylene plastic bags, with a piece of wet cotton inside, to maintain moisture for 72 h. A further 30 leaves per tree were sprayed with sterile water as controls. DNA was extracted using the cetyltrimethylammonium bromide (CTAB) method following the protocol described by Oliveira et al. (2016). Internal transcribed spacer (ITS), partial histone3 (HIS3), and partial glyceraldehyde-3-phosphatedehydrogenase (GAPDH) gene sequences were amplified by polymerase chain reaction (PCR) using ITS1/ITS4 (White et al. 1990), CYLH3F/CYLH3R (Crous et al. 2004), and GDF1/GDR1 (Guerber et al. 2003) primers. The PCR for the ITS amplification were performed according to Oliveira et al. (2014), and for the HIS3 and GAPDH according Damm et al. (2012). Maximum likelihood analysis (with support estimated by a bootstrap analysis with 1,000 replicates) was performed using PhyML 3.0 (Guindon and Gascuel 2003) and launched from Topali 2.5. The colony produced abundant white to light gray aerial mycelium, and an orange viscous mass of conidia (Supplementary Figure S1. B). Conidia were single-celled, smooth, hyaline and sub-cylindrical with rounded ends, 13 (11-15) × 3.5 (3-4) µm (Supplementary Figure S1. C); appressoria were aseptate, brown, subglobose to clavate, 11 (10-12) × 7 (6-8) µm (Supplementary Figure S1. D). BLASTn analysis revealed that the partial gene sequences of ITS (URM 8381 ‒ MZ158701), GAPDH (URM 8381 ‒ MZ189259) and HIS3 (URM 8381 ‒ MZ189260) were 100% identical to Colletotrichum tropicale (CPO 27.830 ‒MN744296/CBS 129983 ‒ MH865615), (CMM 4071 ‒ KC517181/CPO 27.719 ‒MN737355) and (CBS 124949 ‒ KY856395). A maximum likelihood phylogenetic tree was generated by combining all sequenced loci. The phylogenetic tree revealed that sequences of the isolate URM8381 formed a clade with the sequences from the type species of C. tropicale E.I. Rojas, S.A. Rehner & Samuels (CBS 124949) with a high support value (95), which is distinct from other related species (Supplementary Figure S1. E). The sequences from the isolate were deposited in GenBank under the following accession numbers: ITS: MZ158701; GAPDH: MZ189259 and HIS3: MZ189260. C. tropicale was reisolated from the inoculated leaves, and had the same cultural and morphological characteristics as the original isolate. Both detached leaves and leaves on trees were inoculated in the field and presented leaf spot symptoms (Supplementary Figure S1.F), at 6 and 8 days after inoculation, respectively, which further confirms C.tropicale as the causal agent of the symptoms observed on the leaves of C. legalis. The controls did not develop any symptoms (Supplementary Figure S1. G). C. tropicale belongs to the C. gloeosporioides species complex. In Brazil, C. tropicale causes anthracnose on various hosts, including Annona muricata L. (soursop) and Myrciaria dubia (Kunth) McVaugh ("camu-camu") (Costa et al. 2019; Matos et al. 2020). To our knowledge, this is the first report of C. tropicale causing leaf spot on C. legalis. References: Costa, J. F. O., et al. 2019. Eur. J. Plant Pathol. 153:1119. Crous, P. W., et al. 2004. Stud. Mycol. 50:415. Damm, U., et al. 2012. Stud. Mycol. 73:1. Guerber, J. C., et al. 2003. Mycol. 95:87. Guindon, S.; Gascuel, O. 2003. Syst Biol 52(5): 696-704. https://doi.org/10.1080/10635150390235520. IUCN. 2021. http://www.iucnredlist.org. Matos, K. S., et al. 2020. Plant Dis. 104. https://doi.org/10.1094/PDIS-04-19- 0882-PDN Oliveira R. J. V., et al. 2016. N. Hedw. 103:185. White, T. J., et al. 1990. In: Innis, M.A., et al. (Eds.) Academic Press, San Diego, pp. 315-322. http://dx.doi.org/10.1016/b978-0-12-372180-8.50042-1.

7.
Mol Biol Rep ; 48(3): 3027-3030, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33755851

RESUMO

The endemic tree species Calyptranthes clusiifolia (Myrtaceae) plays a relevant ecological role in the forest fragments where it has a common occurrence. In this study, we reported the development of microsatellite markers for C. clusiifolia what will allow a better understanding of the relationship between the forest fragmentation process and the genetic structure and diversity of tree populations. Seven microsatellite markers were developed using an enriched genomic library and characterized in 30 individuals (from three populations). These seven loci were polymorphic and resulted in a total of 23 alleles. The expected heterozygosity (HE) varied from 0.14 (Caly 06) to 0.73 (Caly 22). Linkage disequilibrium between the loci (p > 0.0007) pairs was not detected. The parentage exclusion power of the first (Pe-1) and the second (Pe-2) parents were 0.6099 and 0.8548, respectively. The microsatellite markers developed are indicated for future studies of the genetic diversity in natural populations of C. clusiifolia.


Assuntos
Repetições de Microssatélites/genética , Myrtaceae/genética , Alelos , Loci Gênicos , Polimorfismo Genético
8.
Exp Appl Acarol ; 84(1): 227-239, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33891225

RESUMO

Birds are important hosts in the maintenance and spread of ticks worldwide, including several species of Amblyomma which harbor rickettsial agents as members of the spotted fever group (SFG). The current survey shows the diversity of tick and rickettsial agents infecting ticks on wild birds from an Atlantic rainforest in the state of Bahia, Brazil. A total of 365 birds were captured, representing two orders, 22 families and 51 species, among which 68 specimens (18.6%) were parasitized. Overall, 132 immature ticks (81 larvae and 51 nymphs) were identified to species level, representing six recognized species of the genus Amblyomma: Amblyomma longirostre (n = 45), Amblyomma nodosum (n = 40), Amblyomma varium (n = 5), Amblyomma parkeri (n = 2), Amblyomma coelebs (n = 3) and Amblyomma calcaratum (n = 1). Amplification by PCR and sequencing of rickettsial genes (gltA and ompA), detected the presence of Rickettsia DNA in 12 (9.1%) of the ticks. Rickettsia amblyommatis was the only agent detected in nine larvae and two nymphs of A. longirostre and one nymph of A. varium with 99-100% similarity.


Assuntos
Doenças das Aves , Ixodidae , Rickettsia , Infestações por Carrapato , Carrapatos , Animais , Doenças das Aves/epidemiologia , Aves , Brasil , Rickettsia/genética , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/veterinária
9.
Mol Ecol ; 29(4): 783-796, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31958183

RESUMO

Assessments of spatial and temporal congruency across taxa from genetic data provide insights into the extent to which similar processes structure communities. However, for coastal regions that are affected continuously by cyclical sea-level changes over the Pleistocene, congruent interspecific response will not only depend upon codistributions, but also on similar dispersal histories among taxa. Here, we use SNPs to test for concordant genetic structure among four codistributed taxa of freshwater fishes (Teleostei: Characidae) along the Brazilian Atlantic coastal drainages. Based on population relationships and hierarchical genetic structure analyses, we identify all taxa share the same geographic structure suggesting the fish utilized common passages in the past to move between river basins. In contrast to this strong spatial concordance, model-based estimates of divergence times indicate that despite common routes for dispersal, these passages were traversed by each of the taxa at different times resulting in varying degrees of genetic differentiation across barriers with most divergences dating to the Upper Pleistocene, even when accounting for divergence with gene flow. Interestingly, when this temporal dissonance is viewed through the lens of the species-specific ecologies, it suggests that an ecological sieve influenced whether species dispersed readily, with an ecological generalist showing the highest propensity for historical dispersal among the isolated rivers of the Brazilian coast (i.e., the most recent divergence times and frequent gene flow estimated for barriers). We discuss how our findings, and in particular what the temporal dissonance, despite common geographic passages, suggest about past dispersal structuring coastal communities as a function of ecological and paleo-landscape sieves.


Assuntos
Characidae/genética , Ecologia , Genética Populacional , Genômica , Animais , Brasil , DNA Mitocondrial/genética , Água Doce , Fluxo Gênico , Variação Genética/genética , Filogenia , Filogeografia , Rios , Especificidade da Espécie
10.
Exp Appl Acarol ; 81(3): 457-467, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32643110

RESUMO

Birds are recognized hosts of ticks, especially for the immature stages which may harbor various species and strains of Rickettsia. To explore landscapes inhabited by birds and their ticks would expand the knowledge on host-parasite relationships and the rickettsiae. The aim of this paper was to record the diversity of ticks collected on wild birds and assess the phylogenetic position of a novel Rickettsia strain detected in immature ticks. Birds were captured in the Ibitipoca State Park, located in the Minas Gerais state, southeastern Brazil, as part of a long-term research project on the ecology of ticks, birds and Rickettsia. We found three tick species parasitizing birds: Amblyomma aureolatum (63 larvae, 10 nymphs), Haemaphysalis leporispalustris (28 larvae, seven nymphs) and Amblyomma romarioi (27 larvae). Among these, A. aureolatum was the most abundant species including 54% (73/135) of the collected ticks. New tick-host records were: A. romarioi on Turdus amaurochalinus and H. leporispalustris on Thamnophilus caerulescens, Saltator similis and Zonotrichia capensis. Of the 82 ticks tested for Rickettsia spp. by PCR, two larvae (2.5%) of A. romarioi were infected with 'Candidatus Rickettsia paranaensis', a novel putative Rickettsia species closely related to Rickettsia africae, Rickettsia sibirica and Rickettsia parkeri, as corroborated by our phylogenetic analysis. Finally, we present a list of all records of immature stages of H. leporispalustris on passerine birds in Brazil.


Assuntos
Aves , Ixodidae , Rickettsia , Carrapatos , Animais , Animais Selvagens , Aves/parasitologia , Brasil , Filogenia , Rickettsia/genética
12.
Emerg Infect Dis ; 25(12): 2315-2317, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31742525

RESUMO

We found Rickettsia parkeri in Amblyomma ovale ticks collected in Veracruz, Mexico, in 2018. We sequenced gene segments of gltA, htrA, sca0, and sca5; phylogenetic reconstruction revealed near-complete identity with R. parkeri strain Atlantic Rainforest. Enhanced surveillance is needed in Mexico to determine the public health relevance of this bacterium.


Assuntos
Rickettsia/classificação , Rickettsia/genética , Infestações por Carrapato/epidemiologia , Carrapatos/microbiologia , Animais , Feminino , Genes Bacterianos , Masculino , México/epidemiologia , Filogenia , Vigilância em Saúde Pública
13.
Mol Phylogenet Evol ; 138: 1-16, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31136801

RESUMO

The Brazilian Atlantic Forest has long been considered a global biodiversity hotspot. In the last decade, the phylogeographic patterns of endemic taxa have been unraveling the biogeographic history of the biome. However, highly diverse invertebrate species have still been poorly studied. Sodreana harvestmen (Gonyleptidae) are distributed in most of the humid coastal forests in the southern portion of the Atlantic Forest, a region that has experienced complex topographic evolution and differing climatic conditions since the Early Cretaceous, which likely affected the geographic distribution and diversification of the group. In this study, we investigated the molecular phylogeny and phylogeography of Sodreana to clarify the species relationships and to make inferences about the historical biogeography of the southern Atlantic Forest. We applied coalescent-based phylogenetic analyses using one mitochondrial and three nuclear markers coupled with an ecological niche modeling approach to verify relationships among species, date the main divergence events in the genus, and make inferences concerning possible changes in the geographical distribution and population dynamics from the past. Our results supported the validity of most Sodreana species and suggested that Paleogene-Neogene geomorphologic processes such as the formation of rivers systems, uplift of mountain ranges and related environmental changes have profoundly affected the evolutionary history of Sodreana. The ecological niche models showed that the areas potentially occupied by the species were greatly reduced during Quaternary glacial periods but no recent lineage divergences or genetic bottlenecks were detected, suggesting that climatically stable micro-habitats could have helped maintain populations during drier periods. Our study highlights the importance of humidity-dependent and poor-dispersal taxa in understanding the effects of ancient geological and climate processes on the Atlantic Forest biota.


Assuntos
Aracnídeos/classificação , Florestas , Filogeografia , Animais , Aracnídeos/genética , Teorema de Bayes , Brasil , Núcleo Celular/genética , Variação Genética , Genética Populacional , Haplótipos/genética , Mitocôndrias/genética , Filogenia , Dinâmica Populacional
14.
Med Vet Entomol ; 33(4): 536-540, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30848844

RESUMO

Fleas are insects with a worldwide distribution that have been implicated in the transmission of several pathogens. The present study aimed to investigate the presence of Rickettsia spp. (Rickettsiales: Rickettsiaceae) and Bartonella spp. (Rhizobiales: Bartonellaceae) in fleas from free-ranging crab-eating foxes Cerdocyon thous (Linnaeus, 1766) (Carnivora: Canidae) from Rio Grande do Sul, southern Brazil. Fleas were collected manually from animals and used for the molecular detection of Rickettsia spp. and Bartonella spp. Twenty-nine C. thous were sampled in six municipalities. Four foxes were parasitized by 10 fleas, all of which were identified as Ctenocephalides felis (Bouché, 1935) (Siphonaptera: Pulicidae). DNA from Rickettsia felis Bouyer et al., 2001 and Rickettsia asembonensis Maina et al., 2016 were found in three and eight fleas, respectively. In four fleas, DNA of Bartonella sp. was identified. Phylogenetic analysis grouped Bartonella sp. together with other genotypes previously reported in C. felis worldwide. The scenario described in the present study highlights a Neotropical canid parasitized by the invasive cosmopolitan cat flea, which in turn, is carrying potentially invasive vector-borne microorganisms. These findings suggest that C. felis is adapted to wild hosts in wilderness areas in southern Brazil, hypothetically exposing the Neotropical fauna to unknown ecological and health disturbances.


Assuntos
Bartonella/isolamento & purificação , Canidae/parasitologia , Ctenocephalides/microbiologia , Infestações por Pulgas/veterinária , Rickettsia/isolamento & purificação , Animais , Brasil/epidemiologia , Infestações por Pulgas/epidemiologia , Infestações por Pulgas/parasitologia , Insetos Vetores/microbiologia , Prevalência
15.
Glob Chang Biol ; 24(6): 2272-2283, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29498787

RESUMO

Studies have tested whether model predictions based on species' occurrence can predict the spatial pattern of population abundance. The relationship between predicted environmental suitability and population abundance varies in shape, strength and predictive power. However, little attention has been paid to the congruence in predictions of different models fed with occurrence or abundance data, in particular when comparing metrics of climate change impact. Here, we used the ecological niche modeling fit with presence-absence and abundance data of orchid bees to predict the effect of climate change on species and assembly level distribution patterns. In addition, we assessed whether predictions of presence-absence models can be used as a proxy to abundance patterns. We obtained georeferenced abundance data of orchid bees (Hymenoptera: Apidae: Euglossina) in the Brazilian Atlantic Forest. Sampling method consisted in attracting male orchid bees to baits of at least five different aromatic compounds and collecting the individuals with entomological nets or bait traps. We limited abundance data to those obtained by similar standard sampling protocol to avoid bias in abundance estimation. We used boosted regression trees to model ecological niches and project them into six climate models and two Representative Concentration Pathways. We found that models based on species occurrences worked as a proxy for changes in population abundance when the output of the models were continuous; results were very different when outputs were discretized to binary predictions. We found an overall trend of diminishing abundance in the future, but a clear retention of climatically suitable sites too. Furthermore, geographic distance to gained climatic suitable areas can be very short, although it embraces great variation. Changes in species richness and turnover would be concentrated in western and southern Atlantic Forest. Our findings offer support to the ongoing debate of suitability-abundance models and can be used to support spatial conservation prioritization schemes and species triage in Atlantic Forest.


Assuntos
Abelhas/classificação , Abelhas/fisiologia , Mudança Climática , Animais , Biodiversidade , Brasil , Monitoramento Ambiental , Masculino , Dinâmica Populacional
16.
Antonie Van Leeuwenhoek ; 111(4): 525-531, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29124467

RESUMO

Two strains of a novel yeast species were isolated from rotting wood of an ornamental tree (purple quaresmeira, Tibouchina granulosa, Melastomataceae) in an Atlantic Rainforest area in Brazil. Analysis of the sequences of the internal transcribed spacer (ITS-5.8S) region and the D1/D2 domains of the large subunit rRNA gene showed that this species belongs to the Spathaspora clade, and is phylogenetically related to Spathaspora brasiliensis, Candida materiae and Sp. girioi. The novel species ferments D-xylose, producing ethanol, with amounts between 3.37 and 3.48 g L-1 ethanol from 2% D-xylose. Ascospores were not observed from this new species. The name Spathaspora piracicabensis f. a., sp. nov. is proposed to accommodate these isolates. The type strain is UFMG-CM-Y5867T (= CBS 15054T = ESALQ-I54T). The MycoBank number is MB 822,320.


Assuntos
Filogenia , Saccharomycetales/classificação , Madeira/microbiologia , Brasil , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Fermentação , Floresta Úmida , Saccharomycetales/metabolismo , Especificidade da Espécie , Xilose/metabolismo
17.
Appl Environ Microbiol ; 83(9)2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28213544

RESUMO

In 1953, investigators at the Rocky Mountain Laboratories in Hamilton, MT, described the isolation of a spotted fever group Rickettsia (SFGR) species from Dermacentor parumapertus ticks collected from black-tailed jackrabbits (Lepus californicus) in northern Nevada. Several decades later, investigators characterized this SFGR (designated the parumapertus agent) by using mouse serotyping methods and determined that it represented a distinct rickettsial serotype closely related to Rickettsia parkeri; nonetheless, the parumapertus agent was not further characterized or studied. To our knowledge, no isolates of the parumapertus agent remain in any rickettsial culture collection, which precludes contemporary phylogenetic placement of this enigmatic SFGR. To rediscover the parumapertus agent, adult-stage D. parumapertus ticks were collected from black-tailed jackrabbits shot or encountered as roadkills in Arizona, Utah, or Texas from 2011 to 2016. A total of 339 ticks were collected and evaluated for infection with Rickettsia species. Of 112 D. parumapertus ticks collected in south Texas, 16 (14.3%) contained partial ompA sequences with the closest identity (99.6%) to Rickettsia sp. strain Atlantic rainforest Aa46, an SFGR that is closely related or identical to an SFGR species that causes a mild rickettsiosis in several states of Brazil. A pure isolate, designated strain Black Gap, was cultivated in Vero E6 cells, and sequence analysis of the rrs, gltA, sca0, sca5, and sca4 genes also revealed the closest genetic identity to Rickettsia sp. Atlantic rainforest Aa46. Phylogenetic analysis of the five concatenated rickettsial genes place Rickettsia sp. strain Black Gap and Rickettsia sp. Atlantic rainforest Aa46 with R. parkeri in a distinct and well-supported clade.IMPORTANCE We suggest that Rickettsia sp. Black Gap and Rickettsia sp. Atlantic rainforest Aa46 represent nearly identical strains of R. parkeri and that Rickettsia sp. Black Gap or a very similar strain of R. parkeri represents the parumapertus agent. The close genetic relatedness among these taxa, as well as the response of guinea pigs infected with the Black Gap strain, suggests that R. parkeri Black Gap could cause disease in humans. The identification of this organism could also account, at least in part, for the remarkable differences in severity ascribed to Rocky Mountain spotted fever (RMSF) among various regions of the American West during the early 20th century. We suggest that the wide variation in case fatality rates attributed to RMSF could have occurred by the inadvertent inclusion of cases of milder disease caused by R. parkeri Black Gap.


Assuntos
Dermacentor/microbiologia , Rickettsia/classificação , Rickettsia/isolamento & purificação , Animais , Arizona , Proteínas da Membrana Bacteriana Externa/genética , Dermacentor/crescimento & desenvolvimento , Filogenia , Coelhos/parasitologia , Análise de Sequência de DNA , Homologia de Sequência , Texas , Utah
18.
Ecology ; 98(7): 1750-1756, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28444952

RESUMO

A longstanding paradigm in ecology is that there are positive associations between herbivore diversity, specialization, and plant species diversity, with a focus on taxonomic diversity. However, phytochemical diversity is also an informative metric, as insect herbivores interact with host plants not as taxonomic entities, but as sources of nutrients, primary metabolites, and mixtures of attractant and repellant chemicals. The present research examines herbivore responses to phytochemical diversity measured as volatile similarity in the tropical genus Piper. We quantified associations between naturally occurring volatile variation and herbivory by specialist and generalist insects. Intraspecific similarity of volatile compounds across individuals was associated with greater overall herbivory. A structural equation model supported the hypothesis that plot level volatile similarity caused greater herbivory by generalists, but not specialists, which led to increased understory plant richness. These results demonstrate that using volatiles as a functional diversity metric is informative for understanding tropical forest diversity and indicate that generalist herbivores contribute to the maintenance of diversity.


Assuntos
Biodiversidade , Florestas , Herbivoria , Animais , Insetos , Plantas
19.
Am J Bot ; 104(7): 1073-1087, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28710126

RESUMO

PREMISE OF THE STUDY: The yellow-flowered Aechmea subgenus Ortgiesia (yfAsO) (Bromeliaceae) is a group of seven morphologically similar bromeliads found mostly in the southern Brazilian Atlantic rainforest. The recent origin of this group probably contributes to its taxonomic complexity. The aims of this study were to investigate the levels of genetic diversity and structure at the population and species levels, to gain insight into the processes behind the diversification of the group, and to contribute to the establishment of species boundaries. METHODS: We sequenced two noncoding regions of the chloroplast genome (rpl32-trnL and rps16-trnK) and the nuclear phyC gene in 204 and 153 individuals, respectively, representing the seven species of the group. Phylogeographical and population genetics approaches were used. KEY RESULTS: Three of the seven yfAsO showed some degree of genetic differentiation among species. Divergence time for the group was dated to around 4 million years ago. Areas of conservation value were identified, and a scenario of multiple refugia in the southern Brazilian Atlantic rainforest during the Pleistocene climatic oscillations is suggested. CONCLUSIONS: We hypothesized that incomplete lineage sorting and localized hybridization events are responsible for the low levels of genetic differentiation and the taxonomic complexity observed among and within the seven yfAsO species. Further studies on Aechmea comata and Aechmea kertesziae will be necessary to clarify the boundary between these two species. Most of the populations sampled showed high genetic diversity and/or unique haplotypes; they should be prioritized for conservation purposes.


Assuntos
Bromeliaceae/classificação , Variação Genética , Hibridização Genética , Filogenia , Evolução Biológica , Brasil , Bromeliaceae/genética , Genética Populacional , Haplótipos , Filogeografia , Análise de Sequência de DNA
20.
Ecology ; 97(12): 3315-3325, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27911998

RESUMO

Forest loss threatens biodiversity, but its potential effects on multitrophic ecological interactions are poorly understood. Insect herbivory depends on complex bottom-up (e.g., resource availability and plant antiherbivore defenses) and top-down forces (e.g., abundance of predators and herbivorous), but its determinants in human-altered tropical landscapes are largely unknown. Using structural equation models, we assessed the direct and indirect effects of forest loss on insect herbivory in 40 landscapes (115 ha each) from two regions with contrasting land-use change trajectories in the Brazilian Atlantic rainforest. We considered landscape forest cover as an exogenous predictor and (1) forest structure, (2) abundance of predators (birds and arthropods), and (3) abundance of herbivorous arthropods as endogenous predictors of insect leaf damage. From 12 predicted pathways, 11 were significant and showed that (1) leaf damage increases with forest loss (direct effect); (2) leaf damage increases with forest loss through the simplification of vegetation structure and its associated dominance of herbivorous insects (indirect effect); and further demonstrate (3) a lack of top-down control of herbivores by predators (birds and arthropods). We conclude that forest loss favors insect herbivory by undermining the bottom-up control (presumably reduced plant antiherbivore defense mechanisms) in forests dominated by fast-growing pioneer plant species, and by improving the conditions required for herbivores proliferation.


Assuntos
Cadeia Alimentar , Florestas , Herbivoria/fisiologia , Insetos/fisiologia , Clima Tropical , Vertebrados/fisiologia , Animais , Modelos Biológicos
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