RESUMO
Susceptibility to 'scrapie' disease in goats is influenced by polymorphisms of the prion protein (PRNP) gene. The aim of this study was to identify PRNP gene polymorphisms in a total of 356 scrapie disease-free goats from 10 Turkish native breeds. Eighteen single-nucleotide polymorphisms were detected in the caprine PRNP open-reading frame. Ten previously described amino acid substitutions (I142M, H143R, N146S, N146D, R151H, R154H, P168Q, R211Q, Q222K and P240S) and two novel dimorphisms (G134E and Q163P) were identified. The strongest association between caprine PRNP and relative resistance to scrapie disease has been reported previously for polymorphisms at codons 146 (S/D) and 222 (K). In the present study, these three PrP variants were relatively rare with 6.3%. This is the first report on PRNP gene variation in Turkish native goat breeds and our knowledge of these polymorphisms will assist goat breeding programmes to reduce the risk of scrapie.
Assuntos
Doenças das Cabras/genética , Cabras/genética , Proteínas Priônicas/genética , Scrapie/genética , Animais , Cruzamento , Predisposição Genética para Doença , Doenças das Cabras/epidemiologia , Haplótipos/genética , Polimorfismo de Nucleotídeo Único/genética , Scrapie/epidemiologia , TurquiaRESUMO
To assess genetic diversity and maternal origin of Turkish and Iranian native chicken breeds, we analyzed the mtDNA D-loop sequences of 222 chickens from 2 Turkish (Denizli and Gerze) and 7 Iranian (White Marandi, Black Marandi, Naked Neck, Common Breed, Lari, West Azarbaijan, and New Hampshire) native chicken breeds, together with the available reference sequences of G. gallus gallus in GenBank. The haplotype diversity was estimated as 0.24±0.01 and 0.36±0.02 for Turkish and Iranian populations, respectively. In total, 19 haplotypes were observed from 24 polymorphic sites in Turkish and Iranian native chicken populations. Two different clades or haplogroups (A and E) were found in Turkish and Iranian chickens. Clade A haplotypes were found only in White Marandi, Common Breed and New Hampshire populations. Clade E haplotypes, which are quite common, were observed in Turkish and Iranian populations with 18 different haplotypes, of which Turkish and Iranian chickens, Clade E, haplotype 1 (TRIRE1) was a major haplotype with the frequency of 81.5% (181/222) across all breeds. Compared to red jungle fowl, Turkish and Iranian chicken breeds are closely related to each other. These results suggest that Turkish and Iranian chickens originated from the same region, the Indian subcontinent. Our results will provide reliable basic information for mtDNA haplotypes of Turkish and Iranian chickens and for studying the origin of domestic chickens.
RESUMO
The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds and populations have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 animals, we evaluate the population structure of 134 domesticated bovid breeds. Regardless of the analytical method or sample subset, the three major groups of Asian indicine, Eurasian taurine, and African taurine were consistently observed. Patterns of geographic dispersal resulting from co-migration with humans and exportation are recognizable in phylogenetic networks. All analytical methods reveal patterns of hybridization which occurred after divergence. Using 19 breeds, we map the cline of indicine introgression into Africa. We infer that African taurine possess a large portion of wild African auroch ancestry, causing their divergence from Eurasian taurine. We detect exportation patterns in Asia and identify a cline of Eurasian taurine/indicine hybridization in Asia. We also identify the influence of species other than Bos taurus taurus and B. t. indicus in the formation of Asian breeds. We detect the pronounced influence of Shorthorn cattle in the formation of European breeds. Iberian and Italian cattle possess introgression from African taurine. American Criollo cattle originate from Iberia, and not directly from Africa with African ancestry inherited via Iberian ancestors. Indicine introgression into American cattle occurred in the Americas, and not Europe. We argue that cattle migration, movement and trading followed by admixture have been important forces in shaping modern bovine genomic variation.
Assuntos
Animais Domésticos/genética , Cruzamento , Variação Genética , Filogenia , Alelos , Animais , Bovinos , Frequência do Gene , Genética Populacional , Humanos , Polimorfismo de Nucleotídeo ÚnicoAssuntos
Abelhas/genética , Ciclo-Oxigenase 1/genética , Ciclo-Oxigenase 2/genética , DNA Intergênico/genética , DNA Mitocondrial/genética , Variação Genética/genética , Mutação , Animais , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Desoxirribonucleases de Sítio Específico do Tipo II/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Haplótipos , Irã (Geográfico) , Dados de Sequência Molecular , Polimorfismo Genético , TurquiaRESUMO
The genetic diversity of the Turkish native chicken breeds Denizli and Gerze was evaluated with 10 microsatellite markers. We genotyped a total of 125 individuals from five subpopulations. Among loci, the mean number of alleles was 7.5, expected heterozygosity (H (e)) was 0.665, PIC value was 0.610, and Wright's fixation index was 0.301. H (e) was higher in the Denizli breed (0.656) than in the Gerze breed (0.475). The PIC values were 0.599 and 0.426 for Denizli and Gerze, respectively. A phylogenetic tree was constructed using genetic distance and the neighbor-joining method. Its topology reflects the general pattern of genetic differentiation among the Denizli and Gerze breeds. The present study suggests that Denizli and Gerze subpopulations have a rich genetic diversity. The information about Denizli and Gerze breeds estimated by microsatellite analysis may also be useful as an initial guide in defining objectives for designing future investigations of genetic variation and developing conservation strategies.
