RIPETIZIONE IN TANDEM DEL LOCUS DELL'ALFA LATTOALBUMINA (LALBA) NELLA SPECIE OVINA

Studies on milk proteins revealed that a qualitative and quantitative polymorphism may be often found regarding alpha-lactalbumin (?-LA). In mammals, a similar phenomenon was widely documented in the alpha globin system as the result of a gene duplication. The presence of several, differently expressed alpha-lactalbumin gene (LALBA) products suggests that the mechanism underlying this phenomenon may involve non allelic genes. Molecular investigations performed on water buffalo confirmed the presence of duplicated LALBA gene arrangements and the same results were obtained analyzing the DNA from bovine samples. The duplication of LALBA gene was found in two species belonging to the subfamily Bovinae, proving the duplication to be a widespread phenomenon which might have occurred even before the splitting of the common ancestral species Bovidae; thus, it is highly probable that the phenomenon will also occur in the subfamily Caprinae. This paper reports the preliminary results of investigations, carried out by nested-PCR on Altamurana samples, aiming to analyze the LALBA gene arrangement in the ovine species. The results, though needing further confirmation, support the hypothesis that, similarly to what found in buffalo and cattle, a tandemly repeated copy of the LALBA gene is present in sheep.