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1.
Sci Total Environ ; 734: 139263, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32475721

RESUMO

Garden bird feeding constitutes a massive provision of food that can support bird communities, but there is a growing concern it might favour the establishment of exotic species that could be detrimental to others. How bird species compete with novel species for this anthropogenic food resources needs to be assessed. Here, we investigated competition in wintering bird communities at garden birdfeeders. We evaluated whether - and how much - bird access to resources is hampered by the presence of putative superior competing species, among which the Rose-ringed parakeet, the most abundant introduced species across Europe. Using the nation-wide citizen science scheme BirdLab, in which volunteers record in real-time bird attendance on a pair of birdfeeders during 5-minute sessions, we tested whether i) cumulative bird presence time and richness at birdfeeders, and ii) species probability of presence at birdfeeders, were influenced by three large species (the Eurasian magpie, the Eurasian collared-dove, and the Rose-ringed parakeet). Additionally, we assessed whether the Rose-ringed parakeet occupied resources significantly more than others. Presence of the Rose-ringed parakeet or the Eurasian collared-dove similarly reduced community cumulative presence time at birdfeeders, but only the dove reduced community richness. Each of the three large species influenced the presence of at least one of the six smaller species that could be separately modelled, but effects varied in strength and direction. The Rose-ringed parakeet and the Eurasian collared-dove were among the three species monopolising birdfeeders the longest, substantially more than the Eurasian magpie. Our findings confirm the competitive abilities of the large species studied, but do not suggest that garden bird feeding may alarmingly favour introduced species with detrimental effects on native species. Given the variability of large species' effects on small passerines, direct and indirect interactions among all species must be examined to fully understand the ecological net effects at stake.


Assuntos
Jardins , Espécies Introduzidas , Ração Animal , Animais , Columbidae , Europa (Continente) , Jardinagem , Estações do Ano
2.
Anim Cogn ; 23(4): 819-825, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32242297

RESUMO

Integrating local motion signals detected by the primary motion detector is crucial for representing a rigid, two-dimensional motion. The nature of motion integration has been studied using stimuli consisting of two superimposed sinusoidal gratings of different orientations, called plaid motion, and it has been shown that humans perceive integrated motion in the direction where the component constraint lines are intersected. We previously found that pigeons and humans perceive different movement directions from plaid motion; pigeons responded to the vector average direction of the gratings. Although this suggests that the underlying processes of motion integration differ between the two species, the viewing distance in the pigeon experiment, which used a touch panel procedure, was much smaller than in typical human experiments. The current study investigated the potential effect of viewing distance on the perception of plaid motion in pigeons. We trained six pigeons to detect whether motion directions were tilted leftward or rightward while a visual display was presented 0 or 40 cm from an operant chamber. The pigeons responded to plaid stimuli for both viewing distance conditions as if they perceived motion in the vector average direction of two-component gratings. The result indicates that the species difference in plaid perception is not an artefact of viewing distance and suggests that pigeons use a different strategy than humans for integrating visual motion.


Assuntos
Columbidae , Percepção de Movimento , Animais , Humanos , Movimento (Física) , Orientação , Reconhecimento Visual de Modelos
3.
PLoS One ; 15(3): e0229142, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32134934

RESUMO

Migratory birds can detect the direction of the Earth's magnetic field using the magnetic compass sense. However, the sensory basis of the magnetic compass still remains a puzzle. A large body of indirect evidence suggests that magnetic compass in birds is localized in the retina. To confirm this point, an evidence of visual signals modulation by magnetic field (MF) should be obtained. In a previous study we showed that MF inclination impacts the amplitude of ex vivo electroretinogram (ERG) recorded from isolated pigeon retina. Here we present the results of an analysis of putative MF effect on one component of ERG, the photoreceptor's response, isolated from the total ERG by adding sodium aspartate and barium chloride to the perfusion solution. Photoresponses were recorded from isolated retinae of domestic pigeons Columba livia. The retinal samples were placed in MF that was modulated by three pairs of orthogonal Helmholtz coils. Light stimuli (blue and red) were applied under two inclinations of MF, 0° and 90°. In all the experiments, preparations from two parts of retina were used, red field (with dominant red-sensitive cones) and yellow field (with relatively uniform distribution of cone color types). In contrast to the whole retinal ERG, we did not observe any effect of MF inclination on either amplitude or kinetics of pharmacologically isolated photoreceptor responses to blue or red half-saturating flashes. A possible explanations of these results could be that magnetic compass sense is localized in retinal cells other than photoreceptors, or that photoreceptors do participate in magnetoreception, but require some processing of compass information in other retinal layers, so that only whole retina signal can reflect the response to changing MF.


Assuntos
Migração Animal/fisiologia , Columbidae/anatomia & histologia , Campos Magnéticos , Orientação Espacial/fisiologia , Células Fotorreceptoras de Vertebrados/fisiologia , Retina/anatomia & histologia , Resposta Táctica/fisiologia , Animais , Cor , Eletrorretinografia/veterinária , Fundo de Olho , Luz , Magnetismo , Estimulação Luminosa , Células Fotorreceptoras de Vertebrados/citologia , Retina/citologia , Retina/diagnóstico por imagem , Células Fotorreceptoras Retinianas Cones/citologia , Células Fotorreceptoras Retinianas Cones/fisiologia
4.
BMC Infect Dis ; 20(1): 192, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32131753

RESUMO

BACKGROUND: Human psittacosis, caused by Chlamydia (C.) psittaci, is likely underdiagnosed and underreported, since tests for C. psittaci are often not included in routine microbiological diagnostics. Source tracing traditionally focuses on psittacine pet birds, but recently other animal species have been gaining more attention as possible sources for human psittacosis. This review aims to provide an overview of all suspected animal sources of human psittacosis cases reported in the international literature. In addition, for each animal species the strength of evidence for zoonotic transmission was estimated. METHODS: A systematic literature search was conducted using four databases (Pubmed, Embase, Scopus and Proquest). Articles were included when there was mention of at least one human case of psittacosis and a possible animal source. Investigators independently extracted data from the included articles and estimated strength of evidence for zoonotic transmission, based on a self-developed scoring system taking into account number of human cases, epidemiological evidence and laboratory test results in human, animals, and the environment. RESULTS: Eighty articles were included, which provided information on 136 different situations of possible zoonotic transmission. The maximum score for zoonotic transmission was highest for turkeys, followed by ducks, owls, and the category 'other poultry'. Articles reporting about zoonotic transmission from unspecified birds, psittaciformes and columbiformes provided a relatively low strength of evidence. A genotypical match between human and animal samples was reported twenty-eight times, including transmission from chickens, turkeys, guinea fowl, peafowl, pigeons, ducks, geese, songbirds, parrot-like birds and owls. CONCLUSIONS: Strong evidence exists for zoonotic transmission from turkeys, chickens and ducks, in addition to the more traditionally reported parrot-like animal sources. Based on our scoring system, the evidence was generally stronger for poultry than for parrot-like birds. Psittaciformes should not be disregarded as an important source of human psittacosis, still clinicians and public health officials should include poultry and birds species other than parrots in medical history and source tracing.


Assuntos
Chlamydophila psittaci/genética , Chlamydophila psittaci/imunologia , Doenças das Aves Domésticas/transmissão , Aves Domésticas/microbiologia , Psitacose/diagnóstico , Zoonoses/transmissão , Animais , Columbidae/microbiologia , Genótipo , Humanos , Psitacose/microbiologia , Saúde Pública , Administração em Saúde Pública , Aves Canoras/microbiologia , Estrigiformes/microbiologia
5.
Proc Natl Acad Sci U S A ; 117(9): 4718-4723, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32054784

RESUMO

Voiced sound production is the primary form of acoustic communication in terrestrial vertebrates, particularly birds and mammals, including humans. Developing a causal physics-based model that ultimately links descending vocal motor control to tissue vibration and sound requires embodied approaches that include realistic representations of voice physiology. Here, we first implement and then experimentally test a high-fidelity three-dimensional (3D) continuum model for voiced sound production in birds. Driven by individual-based physiologically quantifiable inputs, combined with noninvasive inverse methods for tissue material parameterization, our model accurately predicts observed key vibratory and acoustic performance traits. These results demonstrate that realistic models lead to accurate predictions and support the continuum model approach as a critical tool toward a causal model of voiced sound production.


Assuntos
Acústica , Simulação por Computador , Laringe/fisiologia , Vocalização Animal , Animais , Columbidae , Hidrodinâmica
6.
Anim Cogn ; 23(3): 503-508, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32086597

RESUMO

Delaying reinforcement typically has been thought to retard the rate of acquisition of an association, but there is evidence that it may facilitate acquisition of some difficult simultaneous discriminations. After describing several cases in which delaying reinforcement can facilitate acquisition, we suggest that under conditions in which the magnitude of reinforcement is difficult to discriminate, the introduction of a delay between choice and reinforcement can facilitate the discrimination. In the present experiment, we tested the hypothesis that the discrimination between one pellet of food for choice of one alternative and two pellets of food for choice of another may be a difficult discrimination when choice consists of a single peck. If a 10-s delay occurs between choice and reinforcement, however, the discrimination is significantly easier. It is suggested that when discrimination between the outcomes of a choice is difficult and impulsive choice leads to immediate reinforcement, acquisition may be retarded. Under these conditions, the introduction of a brief delay may facilitate acquisition.


Assuntos
Comportamento de Escolha , Columbidae , Animais , Comportamento Impulsivo , Esquema de Reforço , Reforço Psicológico
7.
Mikrobiyol Bul ; 54(1): 144-153, 2020 Jan.
Artigo em Turco | MEDLINE | ID: mdl-32050885

RESUMO

Avian chlamydiosis, is a highly contagious, systemic disease occuring in domestic and wild birds. Chlamydia psittaci, the causative agent of the disease, is a gram-negative bacterium in the Chlamydiaceae family that can only live within the cell. The agent can be transmitted directly to humans by contact with infected animals or feces of infected animals. It can also be transmitted by inhalation of fecal dust. Since the disease has a zoonotic character, it is also important in terms of public health. By using the monoclonal antibodies against cell wall proteins (OMP) of C.psittaci, six (A-F) and two (WC and M56) serotypes were determined in mammals. The aim of this study was to investigate and genotype the presence of C.psittaci ompA gene in domestic pigeon feces grown in family management style in ten different districts in Ankara in winter and summer seasons. Within the scope of the study, 100 pigeon stool samples were collected from birdhouses in 10 different districts of Ankara (Beypazari, Haymana, Kizilcahamam, Cubuk, Pursaklar, Bala, Cankaya, Polatli, Golbasi and city center) in two different seasons. DNA extraction from fecal samples was performed by classical methods. The presence of the agent in the extracted DNA samples was investigated by polymerase chain reaction (PCR) analysis of the ompA gene. Two-way sequence analysis of the ompA gene was performed with the primers used in the study from the target DNA products amplified by PCR. The results of sequence analysis were compared with the international database and serotyping/genotyping was performed. In the study, C.psittaci ompA gene was detected in 6 (6%) samples of 100 pigeon stool samples. Among these positive samples, two were from Bala (one sample from winter, one sample from summer), two were from Haymana (one sample from winter, one sample from summer) and two were from Golbasi (one sample from winter, one sample from summer); where the same agent was isolated in the same aviaries in different seasons. In this study, no difference was found between the presence of C.psittaci in pigeon droppings and season. In addition when the sequence analysis of the isolated samples were compared with the World database; all isolates were found to be 100% genotype B and 99% genotype E. In this study, the sequence analysis of the ompA gene of C.psittaci from domestic pigeon feces was determined for the first time in Turkey. Although the presence of C.psittaci in domestic pigeons is low, it is a zoonotic bacterium and is important for the public health.


Assuntos
Proteínas da Membrana Bacteriana Externa , Doenças das Aves , Chlamydophila psittaci , Columbidae , Fezes , Psitacose , Animais , Proteínas da Membrana Bacteriana Externa/genética , Doenças das Aves/microbiologia , Chlamydophila psittaci/genética , Columbidae/microbiologia , Fezes/microbiologia , Genótipo , Psitacose/microbiologia , Turquia
8.
J Zoo Wildl Med ; 50(4): 891-896, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31926520

RESUMO

Clinical assessment of renal function in avian species often involves the measurement of plasma uric acid and blood urea nitrogen, relatively insensitive markers of renal dysfunction and dehydration. In mammals, endogenous creatinine is widely used as an indicator of renal glomerular dysfunction. However, avian species produce primarily creatine. Here, renal creatine, 99mTc99-DTPA (diethylenepentaacetic acid, DTPA) and 99mTc-MAG3 (mercaptoacetyl triglycine, MAG3) renal clearances are characterized in the pigeon avian model by infusing DTPA with inulin and creatine with each tracer and examining the slope of their blood disappearance curves. Clearance curves for inulin and DTPA were parallel, suggesting DTPA is cleared by renal filtration. MAG3 clearance (slope: -2.74 × 105, r2 = 0.97) had a slope almost 10-fold steeper than for DTPA (slope: -6.29 × 104, r2 = 0.90), and orders of magnitude steeper than for creatine (slope: -1.4, r2 = 1.0). These results suggest that DTPA is cleared by glomerular filtration like inulin, while MAG3 is filtered and actively excreted in a manner similar to mammals. In contrast, creatine is filtered and resorbed, has a larger volume of distribution (Vd), or exhibits a greater blood protein binding, making it more complex as a renal marker, when compared with creatinine handling in mammals. The two radiotracers can be readily adapted for use in birds, inviting both qualitative and semiquantitative functional evaluation of avian renal function for research and clinical purposes. The elimination of creatine appears to be more complex requiring further study.


Assuntos
Columbidae/metabolismo , Creatina/metabolismo , Rim/metabolismo , Oligopeptídeos/metabolismo , Ácido Pentético/farmacocinética , Polietilenoimina/análogos & derivados , Animais , Meios de Contraste/farmacocinética , Polietilenoimina/farmacocinética
9.
Science ; 367(6475): 293-297, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31949079

RESUMO

Variable feather overlap enables birds to morph their wings, unlike aircraft. They accomplish this feat by means of elastic compliance of connective tissue, which passively redistributes the overlapping flight feathers when the skeleton moves to morph the wing planform. Distinctive microstructures form "directional Velcro," such that when adjacent feathers slide apart during extension, thousands of lobate cilia on the underlapping feathers lock probabilistically with hooked rami of overlapping feathers to prevent gaps. These structures unlock automatically during flexion. Using a feathered biohybrid aerial robot, we demonstrate how both passive mechanisms make morphing wings robust to turbulence. We found that the hooked microstructures fasten feathers across bird species except silent fliers, whose feathers also lack the associated Velcro-like noise. These findings could inspire innovative directional fasteners and morphing aircraft.


Assuntos
Columbidae/anatomia & histologia , Columbidae/fisiologia , Plumas/ultraestrutura , Voo Animal , Asas de Animais/ultraestrutura , Animais , Tecido Elástico/fisiologia , Tecido Elástico/ultraestrutura
10.
PLoS One ; 15(1): e0228310, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31999757

RESUMO

Of all the known oviparous taxa, female birds lay the most diverse types of eggs that differ in terms of shape, shell pigmentation, and shell structure. The pigmentation of the shell, the weight of the egg, and the composition of the yolk correlate with environmental conditions and the needs of the developing embryos. In this study, we analyzed the structure and protein composition of the vitelline membrane (VM) of ring-necked pheasant, gray partridge, cockatiel parrot, and domestic pigeon eggs. We found that the VM structure is characteristic of each species and varies depending on whether the species is precocial (ring-necked pheasant and gray partridge) or superaltrical (cockatiel parrot and domestic pigeon). We hypothesize that a multilayer structure of VM is necessary to counteract the aging process of the egg. The multilayer structure of VM is only found in species with a large number of eggs in one clutch and is characterized by a long incubation period. An interesting discovery of this study is the three-layered VM of pheasant and partridge eggs. This shows that the formation of individual layers of VM in specific sections of the hen's reproductive system is not confirmed in other species. The number of protein fractions varied between 19 and 23, with a molecular weight ranging from 15 to 250 kDa, depending on the species. The number of proteins identified in the VM of the study birds' eggs is as follows: chicken-14, ring-necked pheasant-7, gray partridge-10, cockatiel parrot-6, and domestic pigeon-23. The highest number of species-specific proteins (21) was detected in the VM of domestic pigeon. This study is the first to present the structure and protein composition in the VM of ring-necked pheasant, gray partridge, cockatiel parrot, and domestic pigeon eggs. In addition, we analyzed the relationship between the hatching specification of birds and the structure of the VM.


Assuntos
Cacatuas/embriologia , Columbidae/embriologia , Proteínas do Ovo/metabolismo , Galliformes/embriologia , Membrana Vitelina/ultraestrutura , Animais , Cacatuas/metabolismo , Columbidae/metabolismo , Proteínas do Ovo/química , Feminino , Galliformes/metabolismo , Masculino , Microscopia Eletrônica de Varredura , Peso Molecular , Mapas de Interação de Proteínas , Proteômica/métodos , Especificidade da Espécie , Membrana Vitelina/metabolismo
11.
Transbound Emerg Dis ; 67(2): 510-517, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31692237

RESUMO

During the years 2010-2018, avipoxvirus (APV) outbreaks were observed in the domestic chickens and pigeons present in the eastern Indian state of Odisha. Based on typical pox lesions, followed by molecular techniques, the overall morbidity was found to be 18%-19.23% and 16.92%-23% in chickens and pigeons, respectively. The cutaneous forms of the disease were observed with varied rates of mortality, being 47.36%-52.77% in chickens and 39.13%-92% in pigeons. PCR amplification targeting the viral P4b core protein-coding gene and the DNA polymerase gene confirmed the presence of APV strains in 10 birds. Subsequent phylogenetic analysis of these two genes confirmed that the circulating strains were members of APV clade A. The subclade analysis revealed the introduction of A1 and A3 subclades in Indian chickens and pigeons, respectively. This study is the first molecular record of APVs circulating in eastern Indian birds (Odisha) and involves the first use of the polymerase gene to reveal the circulating clades of Indian APVs.


Assuntos
Avipoxvirus/classificação , Doenças das Aves/virologia , Galinhas/virologia , Columbidae/virologia , Infecções por Poxviridae/veterinária , Animais , Avipoxvirus/genética , Doenças das Aves/epidemiologia , Índia/epidemiologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/virologia
12.
Mol Biol Evol ; 37(1): 134-148, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31501895

RESUMO

The homing pigeon was selectively bred from the domestic pigeon for a homing ability over long distances, a very fascinating but complex behavioral trait. Here, we generate a total of 95 whole genomes from diverse pigeon breeds. Comparing the genomes from the homing pigeon population with those from other breeds identifies candidate positively selected genes, including many genes involved in the central nervous system, particularly spatial learning and memory such as LRP8. Expression profiling reveals many neuronal genes displaying differential expression in the hippocampus, which is the key organ for memory and navigation and exhibits significantly larger size in the homing pigeon. In addition, we uncover a candidate gene GSR (encoding glutathione-disulfide reductase) experiencing positive selection in the homing pigeon. Expression profiling finds that GSR is highly expressed in the wattle and visual pigment cell layer, and displays increased expression levels in the homing pigeon. In vitro, a magnetic field stimulates increases in calcium ion concentration in cells expressing pigeon GSR. These findings support the importance of the hippocampus (functioning in spatial memory and navigation) for homing ability, and the potential involvement of GSR in pigeon magnetoreception.


Assuntos
Columbidae/genética , Comportamento de Retorno ao Território Vital/fisiologia , Seleção Genética , Animais , Glutationa Redutase/genética , Hipocampo/fisiologia , Memória Espacial
13.
Environ Sci Pollut Res Int ; 27(2): 1585-1597, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31755055

RESUMO

We analysed exposure to Pb and its relationship with lead-based ammunition in seven species of terrestrial game birds-common woodpigeon (Columba palumbus), rock dove (Columba livia), stock dove (Columba oenas), European turtle-dove (Streptopelia turtur), red-legged partridge (Alectoris rufa), Barbary partridge (Alectoris barbara) and common quail (Coturnix coturnix)-from rural and urban areas in different parts of Spain (Valencia, Castilla-La Mancha, Castilla y León, Madrid, Islas Canarias and Navarra). A total of 530 liver samples were analysed, and the presence of Pb pellets was studied in the crop, gizzard and intestine; the state and appearance of these organs were also analysed. The number of specimens suspected to have ingested Pb shot was 28 (5.6%), and the geometric mean concentration of hepatic Pb was 0.054 µg g-1 (wet weight, ww). A low percentage of samples (4.8%) were above the abnormal exposure threshold (0.65 µg g-1 ww), and, in these specimens, renal Pb concentrations were determined. Common woodpigeons and rock doves from Madrid were found to have high concentrations of Pb in their livers, and, so, both species can be considered to be good bioindicators of Pb contamination in rural (common woodpigeons) and urban (rock doves) environments. Partridges bred for hunting may be more prone to ingesting pellets from the environment, a fact that should be taken into account in management decisions.


Assuntos
Columbidae , Coturnix , Monitoramento Ambiental , Galliformes , Chumbo/análise , Animais , Espanha
14.
Genome Biol Evol ; 12(1): 3762-3777, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31882998

RESUMO

Extrachromosomal circular DNA (eccDNA) elements of chromosomal origin are known to be common in a number of eukaryotic species. However, it remains to be addressed whether genomic features such as genome size, the load of repetitive elements within a genome, and/or animal physiology affect the number of eccDNAs. Here, we investigate the distribution and numbers of eccDNAs in a condensed and less repeat-rich genome compared with the human genome, using Columba livia domestica (domestic rock pigeon) as a model organism. By sequencing eccDNA in blood and breast muscle from three pigeon breeds at various ages and with different flight behavior, we characterize 30,000 unique eccDNAs. We identify genomic regions that are likely hotspots for DNA circularization in breast muscle, including genes involved in muscle development. We find that although eccDNA counts do not correlate with the biological age in pigeons, the number of unique eccDNAs in a nonflying breed (king pigeons) is significantly higher (9-fold) than homing pigeons. Furthermore, a comparison between eccDNA from skeletal muscle in pigeons and humans reveals ∼9-10 times more unique eccDNAs per human nucleus. The fraction of eccDNA sequences, derived from repetitive elements, exist in proportions to genome content, that is, human 72.4% (expected 52.5%) and pigeon 8.7% (expected 5.5%). Overall, our results support that eccDNAs are common in pigeons, that the amount of unique eccDNA types per nucleus can differ between species as well as subspecies, and suggest that eccDNAs from repeats are found in proportions relative to the content of repetitive elements in a genome.


Assuntos
Cromossomos/química , Columbidae/genética , DNA Circular , Genoma , Sequências Repetitivas de Ácido Nucleico , Animais , Genoma Humano , Humanos , Músculo Esquelético/química
15.
Gen Comp Endocrinol ; 285: 113230, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31348955

RESUMO

During the ovarian ontogeny in birds, five fundamental events can be recognized: migration and colonization of the primordial germ cells, differentiation and proliferation of oogonies, an organization of germinal nests, beginning of the meiotic process and folliculogenesis. The knowledge of these events is fundamental for the interpretation of the processes involved in the differentiation of female gametes. However, there are only references for some model species such as Gallus gallus domesticus and Coturnix coturnix. In a previous study, the histological structure of embryonic ovaries of Columba livia was revealed. Therefore, the objective of this work is to characterize the processes of meiosis and folliculogenesis C. livia from the analysis of the expression of the GnRH receptor, the 3ßHSD enzyme and the cell proliferation protein PCNA in embryonic and postnatal ovaries. Therefore, the expression of GnRHR, 3ßHSD, and PCNA was revealed in histological testicular and ovarian preparations in embryos (stages 41-43) and neonates (2, 5, 7, 10 and 75 days post-hatching). The present study demonstrates that the fate of germline cells is dictated by their location during gonadal development. Thus, the germline cells located in the cortex of the left gonad enter meiosis, while those in the right gonad and those in the medulla of the left ovary fail to go into meiosis. This indicates that somatic signals, instead of an autonomous cellular mechanism, regulate the entry of the germline cells into meiosis in the C. livia embryo. Future studies will be focused on the analysis of proteins associated with meiotic events and folliculogenesis in embryonic and neonatal ovaries of C. livia, to evaluate the regulation of meiosis in vitro.


Assuntos
3-Hidroxiesteroide Desidrogenases/metabolismo , Columbidae/metabolismo , Meiose , Folículo Ovariano/crescimento & desenvolvimento , Receptores LHRH/metabolismo , Animais , Proliferação de Células , Columbidae/embriologia , Embrião não Mamífero/citologia , Feminino , Células Germinativas/metabolismo , Imuno-Histoquímica , Oócitos/citologia , Oócitos/metabolismo , Folículo Ovariano/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo
16.
Parasitol Res ; 119(2): 447-463, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31883048

RESUMO

In this study, we explore blood parasite prevalence, infection intensity, and co-infection levels in an urban population of feral pigeons Columba livia in Cape Town. We analyze the effect of blood parasites on host body condition and the association between melanin expression in the host's plumage and parasite infection intensity and co-infection levels. Relating to the haemosporidian parasite itself, we study their genetic diversity by means of DNA barcoding (cytochrome b) and show the geographic and host distribution of related parasite lineages in pigeons worldwide. Blood from 195 C. livia individuals was collected from April to June 2018. Morphometric measurements and plumage melanism were recorded from every captured bird. Haemosporidian prevalence and infection intensity were determined by screening blood smears and parasite lineages by DNA sequencing. Prevalence of Haemoproteus spp. was high at 96.9%. The body condition of the hosts was negatively associated with infection intensity. However, infection intensity was unrelated to plumage melanism. The cytochrome b sequences revealed the presence of four Haemoproteus lineages in our population of pigeons, which show high levels of co-occurrence within individual birds. Three lineages (HAECOL1, COLIV03, COQUI05) belong to Haemoproteus columbae and differ only by 0.1% to 0.8% in the cytochrome b gene. Another lineage (COLIV06) differs by 8.3% from the latter ones and is not linked to a morphospecies, yet. No parasites of the genera Leucocytozoon and Plasmodium were detected.


Assuntos
Doenças das Aves/parasitologia , Columbidae/parasitologia , Variação Genética , Haemosporida/genética , Infecções Protozoárias em Animais/parasitologia , Animais , Doenças das Aves/epidemiologia , Citocromos b/genética , Prevalência , Infecções Protozoárias em Animais/epidemiologia , África do Sul/epidemiologia
17.
Res Vet Sci ; 128: 293-298, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31869595

RESUMO

Feral pigeons have increased in urban settings worldwide becoming a potential health risk for humans and other animals. Control and surveillance programs are essential to prevent the possible transmission of zoonotic pathogens carried by pigeons. A surveillance program was carried out in Madrid City (Spain) during 2005-2014 to determine the role of urban pigeons as carriers of zoonotic agents comparing these results with studies performed elsewhere in the last fifteen years. A total of 1372 pigeons were randomly captured and tested for detection of Antimicrobial susceptibility and genetic heterogeneity of Campylobacter and Salmonella isolates were determined. During the first phase (August 2005-July 2010), 428 animals were analyzed individually, while in the second period (August 2010-December 2014), 944 pigeons were analyzed in pools (n = 2-3 in 2010 and n = 5-6 in 2013 and 2014). The most prevalent pathogen during the first phase was Campylobacter spp., (6.57%, 95% confidence interval 3.05-12.10%) followed by Salmonella spp. (4.41%, 95% CI: 2.30-7.58%) and C. psittaci (2.56%, 95% CI: 0.70-6.53%)]. The PCR techniques, used during the 2010-2014 phase of the study, confirmed the presence of Campylobacter spp. (prevalence of 0-14.83%) and C. psittaci (0-12,94%) among pigeons of Madrid. Antimicrobial susceptibility testing suggested low levels of resistance. Presence of zoonotic agents in feral pigeons highlights the importance of surveillance programs on this species, although the relative low prevalence found suggests a limited risk to Public and Animal Health in Madrid.


Assuntos
Doenças das Aves/transmissão , Columbidae/microbiologia , Reservatórios de Doenças/microbiologia , Monitoramento Epidemiológico , Animais , Infecções Bacterianas/prevenção & controle , Infecções Bacterianas/transmissão , Aves , Campylobacter/isolamento & purificação , Chlamydophila psittaci/isolamento & purificação , Humanos , Controle de Pragas , Prevalência , Saúde Pública , Salmonella/isolamento & purificação , Espanha/epidemiologia , Zoonoses/epidemiologia , Zoonoses/prevenção & controle , Zoonoses/transmissão
18.
Q J Exp Psychol (Hove) ; 73(1): 104-114, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31307281

RESUMO

Cue competition refers to phenomena indicating that learning about the relationship between a cue and an outcome is influenced by learning about the predictive significance of other cues that are concurrently present. In two autoshaping experiments with pigeons, we investigated the strength of competition among cues for predictive value. In each experiment, animals received an overexpectation training (A+, D+ followed by AD+). In addition, the training schedule of each experiment comprised two control conditions-one condition to evaluate the presence of overexpectation (B+ followed by BY+) and a second one to assess the strength of competition among cues (C+ followed by CZ-). Training trials were followed by a test with individual stimuli (A, B, C). Experiment 1 revealed no evidence for cue competition as responding during the test mirrored the individual cue-outcome contingencies. The test results from Experiment 2, which included an outcome additivity training, showed cue competition in form of an overexpectation effect as responding was weaker for Stimulus A than Stimulus B. However, the test results from Experiment 2 also revealed that responding to Stimulus A was stronger than to Stimulus C, which indicates that competition among cues was not as strong as predicted by some influential theories of associative learning.


Assuntos
Comportamento Competitivo , Sinais (Psicologia) , Animais , Columbidae , Condicionamento Clássico , Estimulação Luminosa , Esquema de Reforço
19.
Pol J Microbiol ; 68(4): 493-504, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31880893

RESUMO

Bird fecal matter is considered a potential source of pathogenic microbes such as yeast species that contaminate the environment. Therefore, it needs to be scrutinized to assess potential environmental health risks. The aim of this study was to investigate the diversity of the yeasts in pigeon fecal droppings, their antifungal susceptibility patterns, and virulence factors. We used culturing techniques to detect the yeasts in pigeon fecal droppings. The isolates were then characterized based on colony morphologies, microscopic examinations, and biochemical reactions. The molecular identification of all yeast isolates was performed by sequencing of the amplified ITS gene. Genes encoding virulence factors CAP1, CAP59, and PLB were also detected. Antifungal susceptibility patterns were examined by the disk diffusion method. A total of 46 yeast-like isolates were recovered, and they belonged to nine different genera, namely, Cryptococcus, Saccharomyces, Rhodotorula, Candida, Meyerozyma, Cyberlindnera, Rhodosporidium, Millerozyma, and Lodderomyces. The prevalence of two genera Cryptococcus and Rhodotorula was high. None of the yeast isolates exhibited any resistance to the antifungal drugs tested; however, all pathogenic Cryptococcus species were positive for virulence determinants like urease activity, growth at 37°C, melanin production, the PLB and CAP genes. This is the first report on the molecular diversity of yeast species, particularly, Cryptococcus species and their virulence attributes in pigeon fecal droppings in Saudi Arabia.Bird fecal matter is considered a potential source of pathogenic microbes such as yeast species that contaminate the environment. Therefore, it needs to be scrutinized to assess potential environmental health risks. The aim of this study was to investigate the diversity of the yeasts in pigeon fecal droppings, their antifungal susceptibility patterns, and virulence factors. We used culturing techniques to detect the yeasts in pigeon fecal droppings. The isolates were then characterized based on colony morphologies, microscopic examinations, and biochemical reactions. The molecular identification of all yeast isolates was performed by sequencing of the amplified ITS gene. Genes encoding virulence factors CAP1, CAP59, and PLB were also detected. Antifungal susceptibility patterns were examined by the disk diffusion method. A total of 46 yeast-like isolates were recovered, and they belonged to nine different genera, namely, Cryptococcus, Saccharomyces, Rhodotorula, Candida, Meyerozyma, Cyberlindnera, Rhodosporidium, Millerozyma, and Lodderomyces. The prevalence of two genera Cryptococcus and Rhodotorula was high. None of the yeast isolates exhibited any resistance to the antifungal drugs tested; however, all pathogenic Cryptococcus species were positive for virulence determinants like urease activity, growth at 37°C, melanin production, the PLB and CAP genes. This is the first report on the molecular diversity of yeast species, particularly, Cryptococcus species and their virulence attributes in pigeon fecal droppings in Saudi Arabia.


Assuntos
Columbidae/microbiologia , Fezes/microbiologia , Fatores de Virulência/metabolismo , Leveduras/efeitos dos fármacos , Leveduras/isolamento & purificação , Animais , Antifúngicos/farmacologia , Biodiversidade , Fluconazol/farmacologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Testes de Sensibilidade Microbiana , Arábia Saudita , Fatores de Virulência/genética , Leveduras/genética , Leveduras/metabolismo
20.
Acta Vet Hung ; 67(4): 588-601, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31842592

RESUMO

The study compares the effect of one-time administration of nonsteroidal and/or steroidal anti-inflammatory combinations by topical or intramuscular (IM) routes to pigeons with monosodium urate (MSU)-induced arthritis. Forty-five adult domestic pigeons were assigned into nine equal groups: NC, negative control; PC, positive control with arthritis; sham, sham control; T1, meloxicam + hydrocortisone; T2, dexamethasone + piroxicam; T3, meloxicam + dexamethasone; T4, hydrocortisone + piroxicam; T5, dexamethasone + hydrocortisone; T6, meloxicam + piroxicam. Arthritis was also induced in T1 to T6 birds. Meloxicam and dexamethasone were administered by IM injection and the other drugs topically right after the induction of arthritis. Different drug combinations significantly decreased one-leg standing time. Induction of arthritis significantly increased TNF-α and IL-6 levels in synovial fluid and serum corticosterone and epinephrine in the PC group. Administration of drugs to birds of Groups T1 and T5 did not significantly change corticosterone concentration, while all different drug combinations decreased epinephrine level. Drug combinations that demonstrated better analgesic effect more strongly reduced serum epinephrine concentration. Meloxicam + hydrocortisone was the most effective combination in reducing inflammatory cytokines. In conclusion, one-time combination therapy with anti-inflammatory agents was effective in the acute management of inflammatory pain due to MSU-induced arthritis in pigeons, even by the topical route.


Assuntos
Artrite/veterinária , Doenças das Aves/tratamento farmacológico , Columbidae , Dexametasona/uso terapêutico , Hidrocortisona/uso terapêutico , Meloxicam/uso terapêutico , Piroxicam/uso terapêutico , Administração Tópica , Animais , Anti-Inflamatórios/uso terapêutico , Anti-Inflamatórios não Esteroides/uso terapêutico , Artrite/induzido quimicamente , Artrite/tratamento farmacológico , Doenças das Aves/induzido quimicamente , Combinação de Medicamentos , Injeções Intramusculares/veterinária
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