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1.
J Hered ; 115(1): 11-18, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-37910845

RESUMEN

As a highly successful introduced species, house sparrows (Passer domesticus) respond rapidly to their new habitats, generating phenotypic patterns across their introduced range that resemble variation in native regions. Epigenetic mechanisms likely facilitate the success of introduced house sparrows by aiding particular individuals to adjust their phenotypes plastically to novel conditions. Our objective here was to investigate patterns of DNA methylation among populations of house sparrows at a broad geographic scale that included different introduction histories: invading, established, and native. We defined the invading category as the locations with introductions less than 70 years ago and the established category as the locations with greater than 70 years since introduction. We screened DNA methylation among individuals (n = 45) by epiRADseq, expecting that variation in DNA methylation among individuals from invading populations would be higher when compared with individuals from established and native populations. Invading house sparrows had the highest variance in DNA methylation of all three groups, but established house sparrows also had higher variance than native ones. The highest number of differently methylated regions were detected between invading and native populations of house sparrow. Additionally, DNA methylation was negatively correlated to time-since introduction, which further suggests that DNA methylation had a role in the successful colonization's of house sparrows.


Asunto(s)
Metilación de ADN , Gorriones , Humanos , Animales , Gorriones/genética , Epigénesis Genética , Ecosistema
2.
An Acad Bras Cienc ; 95(2): e20200922, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37436196

RESUMEN

Indicator species are frequently used to monitor restoration areas. However, species of conservation concern are usually absent in highly fragmented landscapes, making the selection of indicator species a challenging task. Here, we select indicator species of birds and mammals to be used for the evaluation of restoration sites in a highly fragmented landscape, the Capivara-Taquaruçu Dams region located in north Paraná, Brazil. By using the Index of Biotic Integrity (IBI), we show that the Capivara-Taquaruçu Dams landscape has low IBI values and bird richness when compared with two other landscapes in the north of Paraná. Therefore, we used the Individual Indicate Value to identify birds and mammals associated with forest fragments in the Capivara-Taquaruçu Dams landscape. Six bird and four mammal species were selected as indicators of forest fragments, none of which were of conservation concern. However, monitoring of these species could help evaluate the recovery of restoration sites in the Capivara-Taquaruçu Dams region. Lastly, several species of birds and mammals were frequently recorded in the restoration sites, including vulnerable species such as the lowland tapir (Tapirus terrestris). This is indicative that restoration sites can be important habitats in highly fragmented landscapes despite the loss of biodiversity.


Asunto(s)
Ecosistema , Bosques , Animales , Biodiversidad , Mamíferos , Aves , Conservación de los Recursos Naturales
3.
Int J Parasitol ; 51(9): 719-728, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33722680

RESUMEN

Host phylogenetic relatedness and ecological similarity are thought to contribute to parasite community assembly and infection rates. However, recent landscape level anthropogenic changes may disrupt host-parasite systems by impacting functional and phylogenetic diversity of host communities. We examined whether changes in host functional and phylogenetic diversity, forest cover, and minimum temperature influence the prevalence, diversity, and distributions of avian haemosporidian parasites (genera Haemoproteus and Plasmodium) across 18 avian communities in the Atlantic Forest. To explore spatial patterns in avian haemosporidian prevalence and taxonomic and phylogenetic diversity, we surveyed 2241 individuals belonging to 233 avian species across a deforestation gradient. Mean prevalence and parasite diversity varied considerably across avian communities and parasites responded differently to host attributes and anthropogenic changes. Avian malaria prevalence (termed herein as an infection caused by Plasmodium parasites) was higher in deforested sites, and both Plasmodium prevalence and taxonomic diversity were negatively related to host functional diversity. Increased diversity of avian hosts increased local taxonomic diversity of Plasmodium lineages but decreased phylogenetic diversity of this parasite genus. Temperature and host phylogenetic diversity did not influence prevalence and diversity of haemosporidian parasites. Variation in the diversity of avian host traits that promote parasite encounter and vector exposure (host functional diversity) partially explained the variation in avian malaria prevalence and diversity. Recent anthropogenic landscape transformation (reduced proportion of native forest cover) had a major influence on avian malaria occurrence across the Atlantic Forest. This suggests that, for Plasmodium, host phylogenetic diversity was not a biotic filter to parasite transmission as prevalence was largely explained by host ecological attributes and recent anthropogenic factors. Our results demonstrate that, similar to human malaria and other vector-transmitted pathogens, prevalence of avian malaria parasites will likely increase with deforestation.


Asunto(s)
Enfermedades de las Aves , Haemosporida , Malaria Aviar , Parásitos , Plasmodium , Animales , Enfermedades de las Aves/epidemiología , Bosques , Haemosporida/genética , Humanos , Malaria Aviar/epidemiología , Filogenia , Plasmodium/genética , Prevalencia
4.
Parasitol Res ; 120(2): 605-613, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33415388

RESUMEN

Studies contrasting parasite prevalence and host-parasite community structure between pristine and disturbed environments will improve our understanding of how deforestation affects disease transmission and parasite extinction. To determine how infection rates of a common and diverse group of avian blood parasites (Plasmodium and Haemoproteus) respond to changes in avian host composition after mining, we surveyed 25 bird communities from pristine forests (two forest types: plateau and hillside) and reforested sites in Northeast Amazonia. Infection rates and both parasite and avian host community structure exhibited considerable variation across the deforestation gradient. In opposition to the emerging pattern of lower avian haemosporidian prevalence in disturbed tropical forests in Africa, we show that secondary forests had higher haemosporidian prevalence in one of the largest mining areas of Amazonia. The dissimilarity displayed by bird communities may explain, in part, the higher prevalence of Haemoproteus in reforested areas owing to the tolerance of some bird species to open-canopy forest habitat. On the other hand, deforestation may cause local extinction of Plasmodium parasites due to the loss of their avian hosts that depend on closed-canopy primary forest habitats. Our results demonstrate that forest loss induced by anthropogenic changes can affect a host-parasite system and disturb both parasite transmission and diversity.


Asunto(s)
Apicomplexa/aislamiento & purificación , Enfermedades de las Aves/epidemiología , Interacciones Huésped-Parásitos , Animales , Apicomplexa/genética , Biodiversidad , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/transmisión , Aves , Brasil/epidemiología , Código de Barras del ADN Taxonómico/veterinaria , Ecosistema , Bosques , Geografía , Haemosporida/genética , Haemosporida/aislamiento & purificación , Minería , Plasmodium/genética , Plasmodium/aislamiento & purificación , Prevalencia
5.
Toxicon ; 122: 39-42, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27664832

RESUMEN

Pathological anxiety is among the most common psychiatric illnesses, but current treatment is highly limited. In this study, we investigated the potential anxiolytic-like effects of a peptide isolated from Synoeca surinama venom. Rats treated with this peptide spent more time exploring the open arms of elevated plus maze, which indicates an anxiolytic-like profile for this peptide. This study is the first to show the pharmacological use of S. surinama venom in the treatment of anxiety.


Asunto(s)
Ansiolíticos/farmacología , Péptidos/farmacología , Venenos de Avispas/química , Animales , Relación Dosis-Respuesta a Droga , Femenino , Péptidos/administración & dosificación , Péptidos/aislamiento & purificación , Ratas , Ratas Wistar
6.
Int J Parasitol ; 44(5): 329-38, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24556563

RESUMEN

Biogeographic patterns of parasite diversity are useful for determining how host-parasite interactions can influence speciation. However, variation in methodologies and sampling effort can skew diversity estimates. Avian haemosporidians are vector-transmitted blood parasites represented by over 1300 unique genetic lineages spread across over 40 countries. We used a global database of lineage distributions for two avian haemosporidian genera, Plasmodium and Haemoproteus, to test for congruence of diversity among haemosporidians and their avian hosts across 13 geographic regions. We demonstrated that avian haemosporidians exhibit similar diversity patterns to their avian hosts; however, specific patterns differ between genera. Haemoproteus spp. diversity estimates were significantly higher than those of Plasmodium spp. in all areas where the genera co-occurred, apart from the Plasmodium spp.-rich region of South America. The geographic distributions of parasite genera also differed, with Haemoproteus spp. absent from the majority of oceanic regions while Plasmodium spp. were cosmopolitan. These findings suggest fundamental differences in the way avian haemosporidians diverge and colonise new communities. Nevertheless, a review of the literature suggests that accurate estimates of avian haemosporidian diversity patterns are limited by (i) a concentration of sampling towards passerines from Europe and North America, (ii) a frequent failure to include microscopic techniques together with molecular screening and (iii) a paucity of studies investigating distributions across vector hosts.


Asunto(s)
Biodiversidad , Aves/parasitología , Haemosporida/clasificación , Haemosporida/genética , Filogeografía , Animales , Haemosporida/aislamiento & purificación
7.
PLoS One ; 7(12): e53332, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23285283

RESUMEN

Introduced species are interesting systems for the study of contemporary evolution in new environments because of their spatial and temporal scales. For this study we had three aims: (i) to determine how genetic diversity and genetic differentiation of introduced populations of the house sparrow (Passer domesticus) in Brazil varies with range expansion, (ii) to determine how genetic diversity and differentiation in Brazil compares to ancestral European populations; and (iii) to determine whether selection or genetic drift has been more influential on phenotypic divergence. We used six microsatellite markers to genotype six populations from Brazil and four populations from Europe. We found slightly reduced levels of genetic diversity in Brazilian compared to native European populations. However, among introduced populations of Brazil, we found no association between genetic diversity and time since introduction. Moreover, overall genetic differentiation among introduced populations was low indicating that the expansion took place from large populations in which genetic drift effects would likely have been weak. We found significant phenotypic divergence among sites in Brazil. Given the absence of a spatial genetic pattern, divergent selection and not genetic drift seems to be the main force behind most of the phenotypic divergence encountered. Unravelling whether microevolution (e.g., allele frequency change), phenotypic plasticity, or both mediated phenotypic divergence is challenging and will require experimental work (e.g., common garden experiments or breeding programs).


Asunto(s)
Especiación Genética , Especies Introducidas , Gorriones/anatomía & histología , Gorriones/genética , Animales , Aves/anatomía & histología , Aves/genética , Pesos y Medidas Corporales/veterinaria , Brasil , Flujo Genético , Variación Genética , Genotipo , Repeticiones de Microsatélite
8.
PLoS One ; 6(7): e21905, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21779353

RESUMEN

Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global spread of a common invasive bird, we examined the prevalence and genetic diversity of haemosporidian parasites (order Haemosporida, genera Plasmodium and Haemoproteus) infecting house sparrows (Passer domesticus). We sampled house sparrows (N = 1820) from 58 locations on 6 continents. All the samples were tested using PCR-based methods; blood films from the PCR-positive birds were examined microscopically to identify parasite species. The results show that haemosporidian parasites in the house sparrows' native range are replaced by species from local host-generalist parasite fauna in the alien environments of North and South America. Furthermore, sparrows in colonized regions displayed a lower diversity and prevalence of parasite infections. Because the house sparrow lost its native parasites when colonizing the American continents, the release from these natural enemies may have facilitated its invasion in the last two centuries. Our findings therefore reject the Novel Weapon Hypothesis and are concordant with the Enemy Release Hypothesis.


Asunto(s)
Haemosporida/genética , Plasmodium/genética , Animales , Haemosporida/clasificación , Haemosporida/patogenicidad , Malaria Aviar/parasitología , Plasmodium/clasificación , Plasmodium/patogenicidad , Reacción en Cadena de la Polimerasa , Gorriones/parasitología
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