[Structure of the surface of transformed cells of the L line]

In normal fibroblastoid cells 30 minutes after cultivation the cortical layer would be well defined and demarcated from the adjacent cytoplasma, microfibrillae constituting it are parallel to one another and perpendicular to the cell membrane. In transformed L cells at any terms of cultivation the cortical layers is poorly defined, the boundary with the cytoplasma is indistinct, microfibrillae are disoriented. Microvilli on the cell surface represent narrow projections of the cortical layer and consist mainly of microfibrillae. Microtubules show no definite orientation. The failure of cells L to spread over the substrate is due to an impaired orientation of microfibrillae and microtubules, and formation of fine projections-microvilli.