Characterization of bovine TGM1 and exclusion as candidate gene for ichthyosis in Chianina

Ichthyosis is a heterogeneous group of keratinisation disorders reported both in human and animals. Two inherited forms have been reported in cattle, both characterised by autosomal recessive transmission. Ichthyosis reports in cattle is quite rare and the disease genetic basis are completely unknown. In order to find the causative mutation TGM1 gene was evaluated as candidate gene by comparison with man, where the gene is very frequently associated to autosomal recessive ichthyosis forms. TGM1 was characterised in bovine and three different polymorphisms were identified in 5’end region. 2 microsatellite marker polymorphisms saturating about 10cM in the flanking Bovine TGM1 orthologous region were also considered. No gene mutation as well as marker homozygosity were shown in affected calves. Statistical analysis significantly excluded TGM1 gene as causative for ichthyosis phenotype in the analyzed Chianina cases.