RESUMO
A GWAS was performed for inborn X-linked facial dysmorphia with severe growth retardation in Labrador Retrievers. This lethal condition was mapped on the X chromosome at 17-21 Mb and supported by eight SNPs in complete LD. Dams of affected male puppies were heterozygous for the significantly associated SNPs and male affected puppies carried the associated alleles hemizygously. In the near vicinity to the associated region, RPS6KA3 was identified as a candidate gene causing facial dysmorphia in humans and mice known as Coffin-Lowry syndrome. Haplotype analysis showed significant association with the phenotypes of all 18 animals under study. This haplotype was validated through normal male progeny from a dam with the not-associated haplotype on both X chromosomes but male affected full-sibs with the associated haplotype.
Assuntos
Craniossinostoses/veterinária , Doenças do Cão/genética , Cães/genética , Genes Letais , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Animais , Craniossinostoses/genética , Feminino , Estudos de Associação Genética/veterinária , Haplótipos , Masculino , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , Cromossomo X/genéticaRESUMO
There is evidence that tumor necrosis factor (TNF) may be a proliferation and differentiation factor for B lymphocytes. We found that three of four lymphoblastoid cell lines (ADD, IM-9, W1) secreted TNF-beta and expressed TNF receptors, whereas one pre-B cell leukemia and six Burkitt's lymphoma cell lines had no detectable TNF secretion and, except for one Burkitt's cell line (LOU), very low expression of TNF receptors. When IM-9, W1 or LOU cells were cultured over seven days in the presence of either TNF-alpha or antiserum to TNF-beta there was no difference between their growth rate, endogenous TNF-beta secretion or immunoglobulin secretion compared to untreated cells. These findings indicate that TNF does not have a universal role as an autocrine growth factor in transformed B lymphocytes.