Differential expression of sarcoplasmic protein in meat of sheep reared in Continental Southern Italy

The proteomic analysis defines the identity, the structure and the relative abundance of proteins in a given type of cell and in a specific set of conditions. The analysis of protein profile was carried out to identify possible expression differences of muscular proteins between sheep breeds and use these peculiar profiles as trace back biomarkers. The analyses were carried out on a total of 98 samples of longissimusdorsi and of leg muscles pools from 49 ovine belonging to five breeds: Altamurana (N=9), Bagnolese (N=10), Gentile di Puglia (N=10), Laticauda (N=10) and Leccese (N=10). The protein profile was investigated using analytical proteomic procedures: 2DGE and MALDI-TOF/MS. The two-dimensional maps were compared by image analysis using Image Master 2D-Platinum to define the position and relative intensity (volume %) of every single spot. In the range of our observation, image analysis highlighted 15 spots common to all samples, identified as: Adenilate kinase, DJ-1, Enolase (2 spot), Hemoglobin (Hb), Myoglobin (Myb) (2 spot), Phosphatidilethanolamine binding protein (PEBP), Superoxide dismutase, Triosephosphate isomerase (TPI) (5 spot) and Ubiquitin. With the exception of Enolase, the expression (volume %) of common spots differed between breeds, within the muscle. There were significative (P<0.05) differences of expression between breeds for 5 spots: Enolase, Myb and TPI (2 spots) for the ‘Altamurana’; Ubiquitin for the ‘Gentile di Puglia’ and ‘Leccese’. It was furthermore detected a different expression of some proteins between two breeding ‘bioterritories’: (i) higher expression of Myb and of some TPI spots in the breeds reared in the ‘Pugliese’ ‘bioterritory’; (ii) higher expression of DJ-1, Hb, PEBP and Ubiquitin proteins in the breeds reared in the ‘Sannita’ ‘bioterritory’. These differences might probably be ascribed to environmental effects. Thus obtained results suggest a possible use of the proteomic approach to define physiological peculiarity in specific bioterritories; this may allow to establish a link between ovine meat and the territory that can be used to safeguard local productions.