A novel point mutation within the EDA gene causes an exon dropping in mature RNA in Holstein Friesian cattle breed affected by X-linked anhidrotic ectodermal dysplasia

<p>Abstract</p> <p>Background</p> <p>X-linked anhidrotic ectodermal dysplasia is a disorder characterized by abnormal development of tissues and organs of ectodermal origin caused by mutations in the <it>EDA </it>gene. The bovine <it>EDA </it>gene encodes the ectodysplasin A, a membrane protein expressed in keratinocytes, hair follicles and sweat glands, which is involved in the interactions between cell and cell and/or cell and matrix. Four mutations causing ectodermal dysplasia in cattle have been described so far.</p> <p>Results</p> <p>We identified a new single nucleotide polymorphism (SNP) at the 9^thbase of exon 8 in the <it>EDA </it>gene in two calves of Holstein Friesian cattle breed affected by ectodermal dysplasia. This SNP is located in the exonic splicing enhancer (ESEs) recognized by SRp40 protein. As a consequence, the spliceosome machinery is no longer able to recognize the sequence as exonic and causes exon skipping. The mutation determines the deletion of the entire exon (131 bp) in the RNA processing, causing a severe alteration of the protein structure and thus the disease.</p> <p>Conclusion</p> <p>We identified a mutation, never described before, that changes the regulation of alternative splicing in the <it>EDA </it>gene and causes ectodermal dysplasia in cattle. The analysis of the SNP allows the identification of carriers that can transmit the disease to the offspring. This mutation can thus be exploited for a rational and efficient selection of unequivocally healthy cows for breeding.</p

Genetic variation and relationships among Turkish water buffalo populations

The genetic variation and relationships among six Turkish water buffalo populations,typical of different regions was assessed using a set of twenty-six heterologous (bovine) microsatellite markers. Between 7 and 17 different alleles were identified per microsatellite in a total of 254 alleles. The average number of alleles across all loci in all the analyzed populations was found to be 12.57. The expected mean heterozygosity (HE) per population was between 0.5 and 0.58. Significant departures from Hardy-Weinberg equilibrium were observed for 44 locus-population combinations. Population differentiation was analyzed by estimation of the FST index (values ranging from 0.053 to 0.123) among populations. In the PCA analysis the Merzifon population showed the highest differentiation compared to the others. Also some individuals of the Danamandira population appeared clearly separated. Instead Afyon, Coskun, Pazar and Thural populations represented one single cluster. The assignment of individuals to their source populations, performed using the Bayesian clustering approach implemented in STRUCTURE 2.2 software, has evidenced a high differentiation of Merzifon and Danamandira populations as well. The results of this study could be useful for the development of conservation strategies of the Turkish buffalo