Establishment and characterization of the Cuvier's beaked whale (Ziphius cavirostris) myogenic cell line.

In this study we present the first in vitro model based on a muscle-derived cell line from a male Cuvier's Beaked whale stranded along the Italian coastline. In the myogenic cell line at T0 stage we performed the growth rate assay, the karyotyping, the CBA chromosome banding, G banding, nucleolar organizer regions and telomere analysis and immunocytochemical analysis. The cell characterization at the T2 and T4 stage included: assessment of fusion index, the ultrastructural analysis and immunocytochemical analysis. The population doubling time was determined to be ∼54 h. The cell fusion index at the T2 stage was 8.2 +/- 5 %, at the T4 stage increased at index 28 +/- 10 %. The karyotype analysis revealed a 2n = 42, XY, two pairs of nucleolus organizer regions (NORs), characteristic CBA-banding and PNA-telomeric regions by FISH-mapping. The immunocytochemical results revealed that we generated a heterogeneous population of myogenic cells. A cell population express β-actin, myosin and vimentin and a sub-population of cells was desmin-positive. In details, at the T0 stage, both cell populations were undifferentiated mononucleated myoblast. At the T2 and T4 stage, the cells were capable of fusion in elongated multinucleated myotubes, probably resulting from the fusion of the myoblasts. This Cuvier's Beaked whale cell line, represents a new opportunity to better understand the physiological features of the cetacean Ziphius cavirostris myogenic cells. The possibility of setting up culture conditions that mimic the in vivo microenvironment, strengthen the importance of in vitro models for toxicological studies investigating water pollutants effects on cells.