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1.
Genome Biol Evol ; 2024 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-39462092

RESUMEN

The major histocompatibility complex (MHC) is central in adaptive immunity, with the highly polymorphic MHC genes encoding antigen-presenting molecules. Two MHC class II (MHC-II) loci, DA1 and DA2, pre-date the radiation of extant birds and persist throughout much of the avian phylogeny. Within each locus, the MHC-II molecules are encoded by A- (DAA) and B- (DAB) genes, which are arranged in A-B dyads. However, in passerines (order Passeriformes), the DA2 locus has been lost and the ancestral A-B dyad at the DA1 locus has been replaced by a putatively single A-gene (DAA1) and an array of highly polymorphic B-genes (DAB1). In this study, we genotyped the DAA1 gene of 15 passerine species and confirmed that passerines possess just one copy of DAA1. We then compared selection patterns in DAA1 between passerines and non-passerines and found that exon 2, which encodes the antigen-presenting domain, has been subject to weaker positive selection and stronger negative selection in passerines compared with non-passerines. Additional comparisons showed that the patterns of selection in the passerine DAA1 gene are unlikely to be related to the loss of the DA2 locus. Instead, our findings suggest that the expansion of DAB1 (MHC-IIB) has imposed an evolutionary constraint on the passerine DAA1 (MHC-IIA) gene. We speculate that this constraint may be the result of each DAA1 chain having to form heterodimers with many different DAB1 chains.

2.
Ecol Evol ; 14(9): e70280, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39267692

RESUMEN

Environmental factors such as temperature and humidity influence the distribution of free-living organisms. As climates change, the distributions of these organisms change along with their associated parasites, mutualists and commensals. Less studied, however, is the possibility that environmental conditions may directly influence the distribution of these symbionts even if the hosts are able to persist in altered environments. Here, we investigate the diversity of parasitic lice (Insecta: Phthiraptera) on birds in arid Utah compared to the humid Bahamas. We quantified the parasite loads of 500 birds. We found that the prevalence, abundance and richness of lice was considerably lower among birds in Utah, compared to the Bahamas, despite sampling greater host taxonomic richness in Utah. Our data suggest that as climates change, birds in arid regions will have less diverse louse communities over time, potentially relieving birds of some of the cost of controlling these ectoparasites. Conversely, birds in more humid regions will see an increase in louse diversity, which may require them to invest more time and energy in anti-parasite defense. Additional research with other ectoparasites of birds and mammals across different environmental conditions is needed to more fully understand how climate change may reshape parasite communities, and how these changes could influence their hosts.

3.
Dokl Biol Sci ; 518(1): 261-265, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39212885

RESUMEN

A new genus and species of fossil swallows, Miochelidon eschata gen. et sp. nov., are described from the Lower Miocene of the Baikal region. This is the only Miocene representative of Hirundinidae and the oldest fossil record of the group. The coracoid of Miochelidon combines generalized and specialized features, suggesting a basal position in the family for the genus. The ulna has a more advanced morphology, like in modern swallows. The find indicates a widespread distribution of basal swallows in the Early Miocene.


Asunto(s)
Fósiles , Animales , Siberia , Fósiles/anatomía & histología , Golondrinas/anatomía & histología
4.
Mar Pollut Bull ; 207: 116805, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39128230

RESUMEN

The Amazonian coastal ecosystems face a significant threat from plastic contamination, posing a major risk to their biodiversity. Here, we provide the first evidence of using plastics in nest building by Yellow-cacique Cacique (Cacicus cela) and Greater Kiskadee (Pitangus sulphuratus). During 2023 and 2024, 15 nests built with ropes and fishing lines were recorded in the Brazilian Amazon Coast, a colony of 12 nests in the State of Amapá and one nest in Pará for C. cela, and one nest for P. sulphuratus was observed in Maranhão during the fieldwork, covering all Brazilian Amazon Coast. These nests were observed on the edge of mangroves, built with solid waste from fishing activities, pointing out how environmental pollution can be incorporated into wildlife this issue. Our records emphasize the effect of plastic pollution on two passerine species associated with mangrove forests and the need for conservation measures and further research.


Asunto(s)
Monitoreo del Ambiente , Plásticos , Animales , Brasil , Plásticos/análisis , Comportamiento de Nidificación , Explotaciones Pesqueras
5.
Wellcome Open Res ; 9: 207, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39114491

RESUMEN

We present a genome assembly from an individual male Fringilla coelebs (the chaffinch; Chordata; Aves; Passeriformes; Fringillidae). The genome sequence is 1,209.2 megabases in span. Most of the assembly is scaffolded into 40 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 16.8 kilobases in length.

6.
Artículo en Inglés | MEDLINE | ID: mdl-39188549

RESUMEN

Birds are long-known as important disseminators of ixodid ticks, in which context mostly their latitudinal, south-to-north migration is considered. However, several bird species that occur in the eastern part of the northern Palaearctic are known to migrate westward. In this study, a female tick collected from the sedge warbler, Acrocephalus schoenobaenus, in Lithuania was identified morphologically and analyzed with molecular-phylogenetic methods. In addition, literature data were reviewed on ixodid tick species known to be associated with birds that have recorded east-to-west migratory route in the Palaearctic. The tick collected from A. schoenobaenus was morphologically identified as Ixodes apronophorus. Two mitochondrial genetic markers for this specimen showed 100% identity with a conspecific tick reported previously in Western Siberia, Russia. Based on literature data, as many as 82 bird species from 11 orders were found to have records of ringing in the easternmost part of the northern Palaearctic and recaptures in Europe. Of these bird species, 31 ixodid tick species were reported in the Euro-Siberian region. Nearly all passeriform bird species with east-to-west migration were reported to carry ticks, whereas no reports of tick infestation were documented from the majority of wetland-associated bird species, mostly from the orders Anseriformes and Charadriiformes. The first European sequences of bona fide I. apronophorus revealed genetic connectedness with conspecific ticks reported from Siberia. Since the principal hosts of this tick species are rodents which do not migrate large distances, the most likely explanation for genetic similarity in this direction is dispersal of this tick species via migratory birds. Given the high number of tick species that are known to associate with bird species migrating in westward direction, this appears to be an important means of the gene flow between geographically distant tick populations in the northern Palaearctic.

7.
J Morphol ; 285(8): e21752, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39016160

RESUMEN

Detailed osteological descriptions of the craniomandibular complex of passerine birds are lacking for most species, limiting our understanding of their diversity and evolution. Cowbirds (genus Molothrus) are a small but widespread group of New World nine-primaried songbirds, well-known for their unique brooding parasitic behavior. However, detailed osteological data for cowbirds and other Icteridae are currently scarce and several features of their skulls remain undescribed or poorly known. To address this issue, a detailed comparative osteology of cowbird skulls is presented here for the first time based on data from x-ray microcomputed tomography, dry skeletal data, and multivariate analyses of linear morphometric data. Cowbird skulls offer some functional insights, with many finch-like features probably related to a seed-rich diet that distinguishes them from most other icterids. In addition, features previously overlooked in earlier studies might provide valuable phylogenetic information at different levels of passerine phylogeny (Passerida, Emberizoidea, Icteridae, and Agelaiinae), including some of the otic region and nasal septum. Comparisons among cowbirds show that there is substantial cranial variation within the genus, with M. oryzivorus being the most divergent cowbird species. Within the genus, distantly related species share similar overall skull morphology and proportions, but detailed osteological data allow species identification even in cases of strong convergence. Further efforts are warranted to furnish baseline data for future studies of this iconic group of Neotropical birds and to fully integrate it into phylogenetic comparative frameworks.


Asunto(s)
Cráneo , Microtomografía por Rayos X , Animales , Cráneo/anatomía & histología , Filogenia , Masculino , Osteología , Femenino , Pájaros Cantores/anatomía & histología , Evolución Biológica , Passeriformes/anatomía & histología
8.
Genome Biol Evol ; 16(7)2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38965649

RESUMEN

Inflammasomes are multiprotein complexes that form in response to ligands originating from pathogens as well as alterations of normal cell physiology caused by infection or tissue damage. These structures engage a robust inflammatory immune response that eradicates environmental microbes before they cause disease, and slow the growth of bona fide pathogens. Despite their undeniable utility in immunity, inflammasomes are radically reduced in birds. Perhaps most surprising is that, within all birds, NLRP3 is retained, while its signaling adapter ASC is lost, suggesting that NLRP3 signals via a novel unknown adapter. Crocodilian reptiles and turtles, which share a more recent common ancestor with birds, retain many of the lost inflammasome components, indicating that the deletion of inflammasomes occurred after birds diverged from crocodiles. Some bird lineages have even more extensive inflammasome loss, with songbirds continuing to pare down their inflammasomes until only NLRP3 and CARD8 remain. Remarkably, songbirds have lost caspase-1 but retain the downstream targets of caspase-1: IL-1ß, IL-18, and the YVAD-linker encoding gasdermin A. This suggests that inflammasomes can signal through alternative proteases to activate cytokine maturation and pyroptosis in songbirds. These observations may reveal new contexts of activation that may be relevant to mammalian inflammasomes and may suggest new avenues of research to uncover the enigmatic nature of the poorly understood NLRP3 inflammasome.


Asunto(s)
Aves , Inflamasomas , Animales , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Evolución Molecular
9.
Acta Trop ; 254: 107210, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38599442

RESUMEN

Several species of hard ticks, including those of the genera Ixodes, Haemaphysalis, Amblyomma, and Rhipicephalus, are of medical and veterinary importance and have been reported in association with Neotropical wild birds. Colombia, known for its great bird diversity, has 57 confirmed tick species. However, there are few studies on the association between wild birds and ticks in Colombia. The Orinoquia region, a migratory center in Colombia, provides a unique opportunity to study wild bird-tick associations and their implications for tick-borne disease dynamics. Our study, conducted between October and December 2021, aimed to identify hard ticks infesting resident and migratory wild birds in the department of Arauca and to assess the presence of bacteria from the genera Anaplasma, Borrelia, Ehrlichia, Rickettsia, and piroplasms. A total of 383 birds were examined, of which 21 were infested. We collected 147 ticks, including Amblyomma dissimile (larvae), Amblyomma longirostre (nymphs), Amblyomma mixtum (adults), and Amblyomma nodosum (larvae and nymphs). We did not detect bacterial DNA in the tested ticks; however, piroplasm DNA was detected in ticks from three of the infested birds. Of the 21 bird-tick associations, six are new to the Americas, and interesting documentation of piroplasm DNA in A. longirostre, A. nodosum, and A. dissimile ticks from wild birds in the region. This study provides valuable insights into the ticks associated with wild birds and their role in the dispersal of ticks and pathogens in Colombia, enhancing our understanding of tick life cycles and tick-borne disease dynamics.


Asunto(s)
Animales Salvajes , Enfermedades de las Aves , Aves , Ixodidae , Infestaciones por Garrapatas , Animales , Colombia , Infestaciones por Garrapatas/veterinaria , Infestaciones por Garrapatas/epidemiología , Aves/parasitología , Ixodidae/microbiología , Ixodidae/crecimiento & desarrollo , Ixodidae/clasificación , Animales Salvajes/parasitología , Animales Salvajes/microbiología , Enfermedades de las Aves/parasitología , Enfermedades de las Aves/epidemiología , Borrelia/aislamiento & purificación , Ehrlichia/aislamiento & purificación , Rickettsia/aislamiento & purificación , Rickettsia/genética , Rickettsia/clasificación , Migración Animal , Anaplasma/aislamiento & purificación , Anaplasma/genética , Ninfa/microbiología , Ninfa/crecimiento & desarrollo , Femenino , Masculino , Larva/microbiología , Amblyomma/microbiología
10.
Parasit Vectors ; 17(1): 144, 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38500221

RESUMEN

BACKGROUND: Previous studies on the tick infestation of birds in the Carpathian Basin focused on songbirds (Passeriformes). Thus, the primary aim of the present work was to extend the scope of previous studies, i.e. to include aquatic (water-associated) bird species in a similar context, especially considering that these birds are usually long-distance migrants. METHODS: Between March 2021 and August 2023, 11,919 birds representing 126 species were checked for the presence of ticks. From 352 birds belonging to 40 species, 905 ixodid ticks were collected. Tick species were identified morphologically and/or molecularly. RESULTS: Ticks from avian hosts belonged to seven species: Ixodes ricinus (n = 448), I. frontalis (n = 31), I. festai (n = 2), I. arboricola (n = 36), I. lividus (n = 4), Haemaphysalis concinna (n = 382) and Dermacentor reticulatus (n = 2). Nymphs of I. ricinus occurred with a single activity peak around March-May, whereas its larvae typically infested birds in May, June or July. By contrast, H. concinna usually had its activity maximum during the summer (nymphs in June-July, larvae later in July-August). Interestingly, two ornithophilic species, I. frontalis and I. arboricola, were most active around winter months (between October and April). A significantly lower ratio of aquatic birds was found tick-infested than songbirds. Several new tick-host associations were revealed, including I. ricinus from Greylag Goose (Anser anser) and D. reticulatus from Great Egret (Ardea alba) and Sedge Warbler (Acrocephalus schoenobaenus). Ticks were collected for the first time in Europe from two species of predatory birds as well as from Little Bittern (Ixobrychus minutus). Bird species typically inhabiting reedbeds were most frequently infested with H. concinna, and most ticks localized at their throat, as opposed to forest-dwelling avian hosts, on which I. ricinus predominated and ticks were more evenly distributed. CONCLUSIONS: In the evaluated region, aquatic birds appear to be less important in tick dispersal than songbirds. However, newly revealed tick-host associations in this category attest to their hitherto neglected contribution. The results suggest that the habitat type will have significant impact not only on the species composition but also on the feeding location of ticks on birds.


Asunto(s)
Ixodes , Ixodidae , Passeriformes , Pájaros Cantores , Infestaciones por Garrapatas , Animales , Infestaciones por Garrapatas/epidemiología , Infestaciones por Garrapatas/veterinaria , Ecosistema , Gansos , Ninfa , Larva
11.
Vet Med Sci ; 10(2): e1372, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38358077

RESUMEN

The health, growth and fertility of avian species can be negatively affected by parasite infection. This survey assesses the presence, variety and distribution of internal and external parasites among parrots and perching birds in Mashhad, Iran. This study examined 751 caged pet birds from different species and regions in Mashhad for faecal samples and 132 oral swabs for digestive tract parasites. Furthermore, skin scrapings were conducted on 14 canaries displaying dishevelled feathers. During the study, mortalities and moribund birds that had been referred underwent necropsies to examine internal parasites. Following the formol ether faecal examination, only one Malango parrot tested positive for Heterakoidea eggs among 751 faecal samples (0.13%). Further, one cockatiel showed evidence of parasitic infection with Eimeria spp. (0.13%). However, neither Cryptosporidium nor Giardia protozoa were detected in the samples (0%). Oral swabs revealed no evidence of Trichomonas (0%). On the other hand, skin scraping revealed the presence of the mite Dermanyssus in 7 out of 14 canaries with dishevelled feathers (50%). Of 25 moribund and weak budgerigars, 2 were infected with Acuaria in their proventriculus (8%). In addition, 3 out of 14 deceased myna birds carried the nematode Diplotriana in their coelomic cavities (21.42%). In conclusion, the rate of internal parasites has been relatively low in ornamental birds of Mashhad, whereas the prevalence of external parasites has been higher.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Loros , Passeriformes , Animales , Criptosporidiosis/epidemiología , Criptosporidiosis/parasitología , Irán/epidemiología , Loros/parasitología , Canarios/parasitología
12.
Ecology ; 105(2): e4227, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38038276

RESUMEN

Mast seeding is the episodic, massive production of plant seeds synchronized over large areas. The resulting superabundance of seeds represents a resource pulse that can profoundly affect animal populations across trophic levels. Following years of high seed production, the abundance of both seed consumers and their predators increase. Higher predator abundance leads to increased predation pressure across the trophic web, impacting nonseed consumers such as the wood warbler Phylloscopus sibilatrix through increased nest predation after tree mast years. Over the past 30 years, the frequency of tree seed masts has increased, while wood warbler populations have declined in several regions of Europe. We hypothesized that increasing mast frequencies may have contributed to the observed population declines by creating suboptimal breeding conditions in years after masting. We measured reproductive output in four study areas in central Europe, which was between 0.61 and 1.24 fledglings lower in the years following masting than nonmasting. For each study area, we used matrix population models to predict population trends based on the estimated reproductive output and the local mast frequencies. We then compared the predicted with the observed population trends to assess if the frequency of mast years had contributed to the population dynamics. In Wielkopolska National Park (PL) and Hessen (DE), masting occurred on average only every 4 years and populations were stable or nearly so, whereas in Jura (CH) and Bialowieza National Park (PL), masting occurred every 2 and 2.5 years, respectively, and populations were declining. The simple matrix population models predicted the relative difference among local population trends over the past 10-20 years well, suggesting that the masting frequency may partly explain regional variation in population trends. Simulations suggest that further increases in mast frequency will lead to further declines in wood warbler populations. We show that changes in a natural process, such as mast seeding, may contribute to the decline in animal populations through cascading effects.


Asunto(s)
Passeriformes , Pájaros Cantores , Animales , Fitomejoramiento , Dinámica Poblacional , Europa (Continente) , Árboles , Semillas/fisiología , Reproducción
13.
J Anim Ecol ; 93(4): 393-405, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38100230

RESUMEN

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constrains symbiont populations. We parameterized metabolic theory equations to investigate how bird species' body size and the body size of their feather mites relate to mite abundance according to four potential energy (uropygial gland size) and space constraints (wing area, total length of barbs and number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance across 106 passerine bird species (26,604 individual birds sampled), using phylogenetic modelling and quantile regression. Feather mite abundance was strongly constrained by host space (number of feather barbs) but not by energy. Moreover, feather mite species' body size was unrelated to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.


Asunto(s)
Enfermedades de las Aves , Infestaciones por Ácaros , Ácaros , Passeriformes , Animales , Filogenia , Tamaño Corporal , Infestaciones por Ácaros/veterinaria
14.
Rev. bras. parasitol. vet ; 33(2): e000524, 2024. tab, graf
Artículo en Inglés | LILACS-Express | LILACS, VETINDEX | ID: biblio-1565406

RESUMEN

Abstract The saffron finch, Sicalis flaveola, a passerine bird, can be found in nearly all Brazilian territory and is also raised in captivity. The objective of this work was to determine the prevalence and load of oocysts in captive saffron finches in the municipality of Campos dos Goytacazes, state of Rio de Janeiro and in free-living saffron finches in the municipality of Eugenopolis, state of Minas Gerais. In this analysis, 30 captive and 30 wild birds were assessed. Feces eliminated in a 24-hour period were collected and weighed to determine the number of oocysts per gram of feces (OoPG). Statistical analyses were performed using Microsoft Excel and GraphPad Prism Software. All birds in the present study were positive for one or more species of coccidia. Captive birds had a mean total oocyst count higher than that of wild birds. No significant differences in OoPG counts were observed when comparing males and females or captive and wild birds. We can conclude that due to the fact that birds both eat and defecate in their cages, it is essential to keep them as clean as possible, since captive birds have a higher prevalence of coccidia.


Resumo Canário-da-terra, Sicalis flaveola, uma ave passeriforme, está presente na natureza em praticamente todo o território brasileiro, além de ser criada em cativeiro. O objetivo deste trabalho foi determinar a prevalência e carga de oocistos em canários-da-terra de cativeiro, no município de Campos dos Goytacazes, estado do Rio de Janeiro. E de canários-da-terra de vida livre no município Eugenopolis, estado de Minas Gerais. Para isso, foram utilizadas 30 aves de cativeiro e 30 de vida livre. Fezes eliminadas durante 24h foram coletadas e pesadas para a realização da contagem de oocistos por grama de fezes (OoPG). Análises estatísticas foram feitas com o auxílio do Software Microsoft Excel e Graphpad Prism. Todas as aves do presente estudo estavam positivas para uma ou mais espécie de coccídio. As aves de cativeiro apresentaram média de contagem total de oocistos maior do que as aves de vida livre. Não foi observada diferença significativa nas contagens de OoPG com relação ao sexo e à origem das aves de cativeiro ou de vida livre. Pode-se concluir que, devido ao fato das aves comerem e defecarem em suas gaiolas, é essencial mantê-las as mais limpas possíveis, uma vez que as aves em cativeiro apresentam maior prevalência de coccídios.

15.
Biol Futur ; 74(4): 467-474, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37919466

RESUMEN

Despite broad interest and recent experimentation, there is no single ecological model accounting for the adaptive significance of the diversity of avian eggshell colouration. The often blue-green eggs of Turdus thrushes are a charismatic example of this, having long captured cultural and scientific attention. Although the biology and evolutionary history of "true" thrushes is well understood, little is known about correlated evolution between shifts in habitat and eggshell pigmentation, and how these shifts map with Turdus biogeography. We applied phylogenetic comparative methods to assess the evolutionary timing of divergence and variation of life history traits and eggshell colouration and maculation presence in the genus. We found that eggshell colour diversified independently on several occasions in the past 11 million years, with much of the variation occurring within the last 4 million years. The majority of Turdus species lay blue-green eggs and also tend to be sedentary and forest-dwelling. Diet generalist species and species which have transitioned to a forest habitat are more likely to lay white eggs (10% of studied species). In turn, lineages in any habitat were more likely to transition to blue-green eggs. We found that variation in egg colour is increased in some clades, of which two lineages radiated in South America and the East Palearctic, in the past 2-4 million years. These findings provide support for the hypothesis that white eggs are more conspicuous to predators in open environments and that multiple, non-mutually exclusive constraints operate on the adaptive function of avian eggshell colour.


Asunto(s)
Pájaros Cantores , Animales , Filogenia , Ecosistema , Pigmentación , Bosques
16.
Parasit Vectors ; 16(1): 392, 2023 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-37898783

RESUMEN

BACKGROUND: Among hard ticks (Acari: Ixodidae), the genus Ixodes comprises the highest number of species, which in turn are most numerous in the Afrotropical zoogeographic region. In South Africa extensive morphological studies have been performed on Ixodes species but only few reports included molecular analyses. METHODS: In this study, 58 Ixodes spp. ticks, collected from ten mammalian and eight avian host species in South Africa, were molecularly and phylogenetically analyzed. In addition, a newly collected sample of the Palearctic Ixodes trianguliceps was included in the analyses. RESULTS: Among the ticks from South Africa, 11 species were identified morphologically. The majority of ticks from mammals represented the Ixodes pilosus group with two species (n = 20), followed by ticks resembling Ixodes rubicundus (n = 18) and Ixodes alluaudi (n = 3). In addition, single specimens of Ixodes rhabdomysae, Ixodes ugandanus, Ixodes nairobiensis and Ixodes simplex were also found. Considering bird-infesting ticks, Ixodes theilerae (n = 7), Ixodes uriae (n = 4) and ticks most similar to Ixodes daveyi (provisionally named I. cf. daveyi, n = 2) were identified. Molecular analyses confirmed two species in the I. pilosus group and a new species (I. cf. rubicundus) closely related to I. rubicundus sensu stricto. Phylogenetic trees based on concatenated mitochondrial or mitochondrial and nuclear gene sequences indicated that the subgenus Afrixodes forms a monophyletic clade with bird-associated exophilic ticks (subgenus Trichotoixodes). Ixodes trianguliceps clustered separately whereas I. alluaudi with their morphologically assigned subgenus, Exopalpiger. CONCLUSIONS: Phylogenetic analyses shed new lights on the relationships of Ixodes subgenera when including multiple sequences from subgenus Afrixodes and African as well as Palearctic species of subgenera Trichotoixodes and Exopalpiger. Subgenera Afrixodes and bird-associated Trichotoixodes share common ancestry, suggesting that the latter might have also originated in Africa. Regarding the subgenus Exopalpiger, I. alluaudi is properly assigned as it clusters among different Australian Ixodes, whereas I. trianguliceps should be excluded.


Asunto(s)
Ixodes , Ixodidae , Animales , Ixodes/genética , Filogenia , Sudáfrica , Australia , Ixodidae/genética , Aves , Mamíferos
17.
Microorganisms ; 11(9)2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37764199

RESUMEN

There is growing interest in emerging viruses that can cause serious or lethal disease in humans and animals. The proliferation of cloacal virome studies, mainly focused on poultry and other domestic birds, reveals a wide variety of viruses, although their pathogenic significance is currently uncertain. Analysis of viruses detected in wild birds is complex and often biased towards waterfowl because of the obvious interest in avian influenza or other zoonotic viruses. Less is known about the viruses present in the order Passeriformes, which comprises approximately 60% of extant bird species. This review aims to compile the most significant contributions on the DNA/RNA viruses affecting passerines, from traditional and metagenomic studies. It highlights that most passerine species have never been sampled. Especially the RNA viruses from Flaviviridae, Orthomyxoviridae and Togaviridae are considered emerging because of increased incidence or avian mortality/morbidity, spread to new geographical areas or hosts and their zoonotic risk. Arguably poxvirus, and perhaps other virus groups, could also be considered "emerging viruses". However, many of these viruses have only recently been described in passerines using metagenomics and their role in the ecosystem is unknown. Finally, it is noteworthy that only one third of the viruses affecting passerines have been officially recognized.

18.
Front Immunol ; 14: 1209059, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37483599

RESUMEN

Long-distance migratory animals such as birds and bats have evolved to withstand selection imposed by pathogens across the globe, and pathogen richness is known to be particularly high in tropical regions. Immune genes, so-called Major Histocompatibility Complex (MHC) genes, are highly duplicated in songbirds compared to other vertebrates, and this high MHC diversity has been hypothesised to result in a unique adaptive immunity. To understand the rationale behind the evolution of the high MHC genetic diversity in songbirds, we determined the structural properties of an MHC class I protein, Acar3, from a long-distance migratory songbird, the great reed warbler Acrocephalus arundinaceus (in short: Acar). The structure of Acar3 was studied in complex with pathogen-derived antigens and shows an overall antigen presentation similar to human MHC class I. However, the peptides bound to Acar3 display an unusual conformation: Whereas the N-terminal ends of the peptides display enhanced flexibility, the conformation of their C-terminal halves is rather static. This uncommon peptide-binding mode in Acar3 is facilitated by a central Arg residue within the peptide-binding groove that fixes the backbone of the peptide at its central position, and potentially permits successful interactions between MHC class I and innate immune receptors. Our study highlights the importance of investigating the immune system of wild animals, such as birds and bats, to uncover unique immune mechanisms which may neither exist in humans nor in model organisms.


Asunto(s)
Quirópteros , Pájaros Cantores , Animales , Humanos , Pájaros Cantores/genética , Pájaros Cantores/metabolismo , Antígenos de Histocompatibilidad Clase I , Péptidos/metabolismo , Presentación de Antígeno , Antígenos HLA
19.
J. Health Sci. Inst ; 41(2): 77-84, apr-jun 2023. Figuras e Tabelas
Artículo en Portugués | LILACS | ID: biblio-1531179

RESUMEN

A criação amadora de aves passeriformes nativas é regulamentada pela Instrução Normativa nº 10/2011, sendo proibida a captura destes animais diretamente da natureza. Além disso, aquele que deseja praticar essa atividade deve atentar-se a Lei de Crimes Ambientais, que dispõe sobre as sanções penais e administrativas derivadas de condutas e atividades lesivas ao meio ambiente. Nesse sentido, um diagnóstico da atuação do órgão estadual (IBRAM) permite averiguar bem como fornecer um panorama da criação de passeriformes em cativeiro no Distrito Federal. Com o objetivo de avaliar a conjuntura da fiscalização referente à fauna silvestre, foi realizado o levantamento das autuações efetuadas pelo Brasília Ambiental no período de 2017 a 2021, tendo como base os criadores cadastrados no Sistema de Cadastro de Passeriformes, conhecido como SisPass. Em relação às apreensões, foram totalizados 1.066 indivíduos no período de estudo de 39 espécies. As espécies de aves mais apreendidas foram canário-da-terra (Sicalis flaveola), baiano (Sporophila nigricollis) e o pássaropreto (Gnorimopsar chopi). Verificou-se que das dez espécies mais apreendidas, nove integram a lista das dez espécies mais criadas no SisPass. No que diz respeito ao grau de ameaça, somente a espécie Sporophila maximiliani (bicudo-verdadeiro) foi classificada como ameaçada em extinção. Quanto aos locais das infrações e apreensões, observou-se maior domínio nas regiões administrativas de Planaltina, Santa Maria e São Sebastião. Por fim, as informações levantadas neste estudo colaboram para a disseminação de dados a respeito da criação irregular de aves silvestres no Distrito Federal e tomada de decisão por gestores públicos.


Asunto(s)
Animales , Aves , Passeriformes , Especies en Peligro de Extinción , Sanciones por Daños Ambientales
20.
Comp Immunol Microbiol Infect Dis ; 95: 101964, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36857999

RESUMEN

Enterocytozoon bieneusi has been classified as an emerging infectious organism (microsporidium) due to the global increase in the number of cases infecting both humans and animals. The goal of this study was to use the polymerase chain reaction method to determine the prevalence and risk factors associated with E. bieneusi infection among pet birds in Mosul, Iraq. Faecal samples from a total of six hundred and twenty-eight pet birds belonging to fifteen (15) different species were analyzed by targeting the internal transcribed spacer (ITS) of the rRNA gene. Of the total number of pet birds sampled, 203 tested positive for the parasite, representing 32.32% (95% CI = 28.75-36.06) of the sampled population. There was a significant difference (p < 0.01) in the prevalence of E. bieneusi infection among the different species of pet birds, with the highest prevalence recorded among Eurasian bullfinches (Pyrrhula pyrrhula) (64.06%; 95% CI = 55.48-72.02), budgerigars (Melopsittacus undulatus) (48.72%; 95% CI = 40.93-56.55), Fischer's lovebirds (Agapornis fischeri) (25.00%; 95% CI = 13.45-40.05), and macaws parrots (Ara ararauna) (25.00%; 95% CI = 1.25-75.77). The order, source, and health status of pet birds were significantly (p < 0.05) associated with the prevalence of E. bieneusi infection among pet birds in Mosul, Iraq. In conclusion, the level of prevalence of E. bieneusi among pet birds may increase the risk of infection for owners of pet birds in Iraq.


Asunto(s)
Enterocytozoon , Microsporidiosis , Humanos , Animales , Enterocytozoon/genética , Prevalencia , Irak/epidemiología , Microsporidiosis/epidemiología , Microsporidiosis/veterinaria , Genotipo , Aves , Heces/parasitología , Filogenia , China/epidemiología
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