In culture, A-10 myoblasts often behave in a manner that is suggestive of their normal role in the vertebrate body, which entails cellular fusion and their differentiation into multinucleated myotubes, the immature form of muscle fibers. Three cells are initially present in the field of view of this video, the upper two of which are clearly attached to one another. The cell along the bottom edge has also apparently formed connective junctions with one or more cells out of view because though there is a flurry of activity along its margins and the cell undergoes numerous shape contortions during the time-lapse sequence, it is never successfully able to migrate across the culture medium. Meanwhile, the cell pair can only be seen releasing their connections with one another when one of the myoblasts retracts all of its surface extensions before undergoing mitosis.

As demonstrated, before A-10 myoblasts divide their shape changes drastically. When in contact with a flat surface, such as that of an imaging chamber, the cells tend to spread out and develop an appearance similar to that of a fried egg. Biochemical changes that dictate the myoblast cell cycle, however, cause the cells to assume the shape of a nearly perfect sphere before dividing. The symmetry of the temporarily assumed cell shape simplifies the duplication of cellular contents and facilitates their even distribution into the new daughter cells, each of which should be identical to the other upon separation. The daughter cells that are formed during this time-lapse sequence quickly form connections with the neighboring cell that was previously connected to their parent cell.

Each observable A-10 myoblast exhibits a single large nucleus, which contains nucleoli and is surrounded by mitochondria. The mitochondria display a granular appearance in the video. The broad, flattened areas around the periphery of each cell are lamellipodia, surface structures rich in actin filaments that are organized in a manner similar to a net. The narrow, finger-like projections extending out from the cells are filopodia. The actin filaments present in filopodia are arranged into loose bundles held together by fimbrin and other bundling proteins.