RESUMO
The widespread use of elite sires by means of artificial insemination in livestock breeding leads to the frequent emergence of recessive genetic defects, which cause significant economic and animal welfare concerns. Here we show that the availability of genome-wide, high-density SNP panels, combined with the typical structure of livestock populations, markedly accelerates the positional identification of genes and mutations that cause inherited defects. We report the fine-scale mapping of five recessive disorders in cattle and the molecular basis for three of these: congenital muscular dystony (CMD) types 1 and 2 in Belgian Blue cattle and ichthyosis fetalis in Italian Chianina cattle. Identification of these causative mutations has an immediate translation into breeding practice, allowing marker assisted selection against the defects through avoidance of at-risk matings.
Assuntos
Animais Domésticos/genética , Doenças dos Bovinos/genética , Mapeamento Cromossômico , Genes Recessivos/genética , Marcadores Genéticos/genética , Polimorfismo de Nucleotídeo Único/genética , Transportadores de Cassetes de Ligação de ATP/genética , Sequência de Aminoácidos , Animais , Animais Domésticos/crescimento & desenvolvimento , Cruzamento , Bovinos , Células Cultivadas , Primers do DNA/química , Distonia/congênito , Distonia/genética , Distonia/veterinária , Feminino , Perfilação da Expressão Gênica , Ligação Genética , Proteínas da Membrana Plasmática de Transporte de Glicina/genética , Humanos , Masculino , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Locos de Características Quantitativas , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Homologia de Sequência de AminoácidosRESUMO
Ichthyosis is a heterogeneous group of keratinization disorders reported both in human and animals. Two rare, inherited forms have been reported in cattle, both characterized by autosomal recessive transmission. Because mutations of transglutaminase 1 (TGM1) gene are associated with autosomal recessive ichthyosis in people, this gene was investigated as a candidate for the diseases in cattle. Three different polymorphisms were identified in 5' end region of cattle TGM1. Marker homozygosity was not found among affected calves. Linkage analysis excluded (logarithmic odds [LOD] score -2.0) TGM1 as the cause for ichthyosis phenotype in the analyzed Chianina cases.