RESUMO
Ticks consume resources from their hosts shaping their life-history traits and are vectors of many zoonotic pathogens. Several studies have focused on the health effects of blood-sucking ectoparasites on avian hosts, but there is limited information on the effects of ticks on adult and sub-adult birds, which may actively avoid ticks and are likely to present low infestation intensities. We evaluated the effects of the presence of feeding ticks and intensity of infestation on health variables of avian hosts. We also evaluated whether these variables were affected by tick infection by Borrelia burgdorferi sensu lato (s.l.) and by the presence of Borrelia infection on the birds' skin. Presence of parasite association among ticks, haemosporidea and Borrelia within the bird-host was also tested. We found that infestation by ticks significantly increased heterophyl/lymphocyte ratio in Turdus merula suggesting increased stress. This was especially evident at high infestation intensities when a significant decrease in body mass and body condition (body mass corrected for size) was also observed. Erithacus rubecula infested with more than 10 larvae tended to have lower haematocrit and blood haemoglobin. Plasma globulin concentration in T. merula tended to be affected by the presence of attached ticks and their infection with Borrelia, but this depended on the age of the bird. No association was detected among ticks, haemosporidea and Borrelia infection. We showed that ticks have detrimental effects on their avian hosts even under natural infestation conditions and that confirmed Borrelia reservoir hosts may also present symptoms of infection, though these may be subtle.
Assuntos
Doenças das Aves/fisiopatologia , Aves , Borrelia burgdorferi/patogenicidade , Doença de Lyme/veterinária , Infestações por Carrapato/veterinária , Carrapatos , Animais , Vetores Aracnídeos/parasitologia , Doenças das Aves/parasitologia , Doenças das Aves/transmissão , Aves/microbiologia , Aves/parasitologia , Reservatórios de Doenças/veterinária , Feminino , Doença de Lyme/fisiopatologia , Doença de Lyme/transmissão , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/patologia , Infestações por Carrapato/transmissão , Carrapatos/microbiologia , Carrapatos/parasitologiaRESUMO
We made a molecular study of 40 opossums, Didelphis albiventris, from an urban fragment of the Atlantic Rainforest in southeastern Brazil, analyzing a 653-bp sequence of cytochrome c oxidase, subunit I. We found three close connected haplotypes, with low nucleotide diversity and a haplotype diversity of 59.1% and confirmed sympatry between D. albiventris and D. aurita in this region. The clear phylogenetic separation shows the appropriateness of DNA barcode identification methodology for effectively discriminating between these opossum species.
Assuntos
Cidades , Código de Barras de DNA Taxonômico/métodos , Didelphis/classificação , Didelphis/genética , Árvores , Animais , Oceano Atlântico , Brasil , Genética Populacional , Geografia , Haplótipos/genética , Dados de Sequência Molecular , Filogenia , Especificidade da EspécieRESUMO
Epiperipatus acacioi (Onychophora: Peripatidae) is an endemic species of the Atlantic rainforest in southeastern Brazil, with a restricted known distribution, found only in two nearby areas (Tripuí and Itacolomi). Mitochondrial gene COI sequences of 93 specimens collected across the known range of E. acacioi were used to assess the extant genetic diversity and patterns of genetic structure, as well as to infer the demographic history of this species. We found considerable variability within the populations, even though there has been recent environmental disturbance in these habitats. The samples from the two areas where this species is found showed significantly different COI sequences and constitute two distinct populations [exact test of sample differentiation (P = 0.0008) and pairwise F(ST) analyses (F(ST) = 0.214, P < 0.00001)]. However, there was little genetic differentiation among samples from different sampling sites within populations, suggesting that the potential for dispersal of E. acacioi greater than would have been expected, based on their cryptic behavior and reduced vagility. Mismatch analyses and neutrality tests revealed evidence of recent population expansion processes for both populations, possibly related to variations in the past distribution of this species.
Assuntos
DNA Mitocondrial/genética , Espécies em Perigo de Extinção , Variação Genética/fisiologia , Genética Populacional , Animais , BrasilRESUMO
A new, quick, and inexpensive method for detecting the bovine acyl-CoA:diacylglycerol acyltransferase1 (DGAT1) polymorphism (K232A) through tetra-primer amplification refractory mutation system by PCR (ARMS-PCR) was developed in the present investigation. The DGAT1 gene was recently identified as underlying variation in milk production traits. To date, PCR techniques such as PCR-RFLP have been used for detecting the DGAT1 K232A polymorphism, despite being expensive and laborious. The method proposed here, a tetra-primer ARMS-PCR, showed 100% sensitivity and specificity when compared with PCR-RFLP results obtained in a sample of 80 animals tested in a double-blind system. Our results suggest that the use of tetra-primer ARMS-PCR for DGAT1 K232A polymorphism genotyping could greatly reduce costs providing information for both research purposes and for dairy cattle breeders who perform DGAT1 genotyping for gene-assisted selection.
Assuntos
Bovinos/genética , Indústria de Laticínios/métodos , Diacilglicerol O-Aciltransferase/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo Genético/genética , AnimaisRESUMO
Recent reports identified DGAT1 (EC 2.3.1.20) harboring a lysine to alanine substitution (K232A) as a candidate gene with a strong effect on milk production traits. Our objective was to estimate the frequency of the DGAT1 K232A polymorphism in the main Zebu and Taurine breeds in Brazil as well as in Zebu x Taurine crossbreds as a potential QTL for marker-assisted selection. Samples of 331 animals from the main Brazilian breeds, Nellore, Guzerat, Red Sindhi, Gyr, Holstein, and Gyr x Holstein F1 were genotyped for DGAT1 K232A polymorphism (A and K alleles) using the PCR-RFLP technique. The highest frequency of the A allele was found in the Holstein sample (73%) followed by Gyr x Holstein F1 (39%). Gyr and Red Sindhi showed low frequencies of A alleles (4 and 2.5%, respectively). The A allele was not found in the Nellore and Guzerat samples. Our results could be used to guide association studies between this locus and milk traits in these breeds.
Assuntos
Bovinos/genética , Diacilglicerol O-Aciltransferase/genética , Leite/química , Polimorfismo Genético/genética , Locos de Características Quantitativas/genética , Animais , Brasil , Cruzamento , Cruzamentos Genéticos , Feminino , Frequência do Gene , Marcadores Genéticos , Genótipo , Masculino , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de RestriçãoRESUMO
Recent reports identified DGAT1 (EC 2.3.1.20) harboring a lysine to alanine substitution (K232A) as a candidate gene with a strong effect on milk production traits. Our objective was to estimate the frequency of the DGAT1 K232A polymorphism in the main Zebu and Taurine breeds in Brazil as well as in Zebu x Taurine crossbreds as a potential QTL for marker-assisted selection. Samples of 331 animals from the main Brazilian breeds, Nellore, Guzerat, Red Sindhi, Gyr, Holstein, and Gyr x Holstein F1 were genotyped for DGAT1 K232A polymorphism (A and K alleles) using the PCR-RFLP technique. The highest frequency of the A allele was found in the Holstein sample (73%) followed by Gyr x Holstein F1 (39%). Gyr and Red Sindhi showed low frequencies of A alleles (4 and 2.5%, respectively). The A allele was not found in the Nellore and Guzerat samples. Our results could be used to guide association studies between this locus and milk traits in these breeds.