Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Primates ; 61(2): 331-338, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31903513

RESUMO

Functional explanations for loud calling in nocturnal primates include territorial or sexual advertisement, maintenance of cohesiveness, and group coordination. It is generally accepted that loud calls of lesser galagos (genus Galago) are used for territorial advertisement and long-distance spacing. Field studies suggest that they are uttered at dusk and dawn, when the animals leave and reunite at their sleeping sites. However, empirical validation of these inferences is lacking. We conducted 16-night-long acoustic monitoring of a northern lesser galago (G. senegalensis) population in Senegal and quantified the occurrence of loud calls throughout the night. We hypothesized that significantly more of these calls would be emitted at dusk and dawn if they were used for territorial advertisement and long-distance spacing. This hypothesis was only partially supported, as we found an asymmetrical distribution of loud calls, which significantly increased only before and at dawn. The finding that the relatively early increase in vocal activity was not directly related to approaching and entering sleeping sites suggests that the northern lesser galagos' loud calls differ in function from reassembly calls described for other species of nocturnal primates. Furthermore, the early onset cannot be explained by changes in the intensity of sunlight, moonlight or starlight, which suggests that a different stimulus, most likely internal, elicits early-morning calling behavior in northern lesser galagos.


Assuntos
Galago/fisiologia , Vocalização Animal , Acústica , Animais , Ritmo Circadiano , Luz , Senegal
2.
PLoS One ; 10(12): e0143807, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26636975

RESUMO

The Czechoslovakian Wolfdog is a unique dog breed that originated from hybridization between German Shepherds and wild Carpathian wolves in the 1950s as a military experiment. This breed was used for guarding the Czechoslovakian borders during the cold war and is currently kept by civilian breeders all round the world. The aim of our study was to characterize, for the first time, the genetic composition of this breed in relation to its known source populations. We sequenced the hypervariable part of the mtDNA control region and genotyped the Amelogenin gene, four sex-linked microsatellites and 39 autosomal microsatellites in 79 Czechoslovakian Wolfdogs, 20 German Shepherds and 28 Carpathian wolves. We performed a range of population genetic analyses based on both empirical and simulated data. Only two mtDNA and two Y-linked haplotypes were found in Czechoslovakian Wolfdogs. Both mtDNA haplotypes were of domestic origin, while only one of the Y-haplotypes was shared with German Shepherds and the other was unique to Czechoslovakian Wolfdogs. The observed inbreeding coefficient was low despite the small effective population size of the breed, possibly due to heterozygote advantages determined by introgression of wolf alleles. Moreover, Czechoslovakian Wolfdog genotypes were distinct from both parental populations, indicating the role of founder effect, drift and/or genetic hitchhiking. The results revealed the peculiar genetic composition of the Czechoslovakian Wolfdog, showing a limited introgression of wolf alleles within a higher proportion of the dog genome, consistent with the reiterated backcrossing used in the pedigree. Artificial selection aiming to keep wolf-like phenotypes but dog-like behavior resulted in a distinctive genetic composition of Czechoslovakian Wolfdogs, which provides a unique example to study the interactions between dog and wolf genomes.


Assuntos
Amelogenina/genética , Quimera/genética , DNA Mitocondrial/genética , Cães/genética , Haplótipos , Lobos/genética , Animais , Tchecoslováquia , Feminino , Masculino
3.
PLoS One ; 9(1): e86409, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24466077

RESUMO

Hybridization and introgression can impact the evolution of natural populations. Several wild canid species hybridize in nature, sometimes originating new taxa. However, hybridization with free-ranging dogs is threatening the genetic integrity of grey wolf populations (Canis lupus), or even the survival of endangered species (e.g., the Ethiopian wolf C. simensis). Efficient molecular tools to assess hybridization rates are essential in wolf conservation strategies. We evaluated the power of biparental and uniparental markers (39 autosomal and 4 Y-linked microsatellites, a melanistic deletion at the ß-defensin CBD103 gene, the hypervariable domain of the mtDNA control-region) to identify the multilocus admixture patterns in wolf x dog hybrids. We used empirical data from 2 hybrid groups with different histories: 30 presumptive natural hybrids from Italy and 73 Czechoslovakian wolfdogs of known hybrid origin, as well as simulated data. We assessed the efficiency of various marker combinations and reference samples in admixture analyses using 69 dogs of different breeds and 99 wolves from Italy, Balkans and Carpathian Mountains. Results confirmed the occurrence of hybrids in Italy, some of them showing anomalous phenotypic traits and exogenous mtDNA or Y-chromosome introgression. Hybridization was mostly attributable to village dogs and not strictly patrilineal. The melanistic ß-defensin deletion was found only in Italian dogs and in putative hybrids. The 24 most divergent microsatellites (largest wolf-dog FST values) were equally or more informative than the entire panel of 39 loci. A smaller panel of 12 microsatellites increased risks to identify false admixed individuals. The frequency of F1 and F2 was lower than backcrosses or introgressed individuals, suggesting hybridization already occurred some generations in the past, during early phases of wolf expansion from their historical core areas. Empirical and simulated data indicated the identification of the past generation backcrosses is always uncertain, and a larger number of ancestry-informative markers is needed.


Assuntos
Marcadores Genéticos , Hibridização Genética , Tipagem de Sequências Multilocus , Animais , Análise por Conglomerados , DNA Mitocondrial , Cães , Evolução Molecular , Feminino , Variação Genética , Genética Populacional , Genótipo , Itália , Masculino , Repetições de Microssatélites , Lobos , Cromossomo Y , beta-Defensinas/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA