Abstract
To investigate the contention that some forms of pathological change in differentiated tissues may result from alteration in the structures underlying them rather than from abnormality within their cells, flakes of tracheal epithelium from adult mice were cultured on glass and on a layer of reconstituted collagen in chambers which permitted direct observation by phase contrast. The epithelium survived well in culture and persistence of differentiation was shown by the continued presence of actively beating cilia on many cells.
Attachment and spreading of the flakes occurred far more readily on collagen than on glass and was best when the collagen was so prepared as to have a fibrous upper surface. Whereas on glass the cells showed few mitoses and assumed a flattened appearance as soon as they migrated from the explants, on collagen there were frequent mitoses, and the cells retained a closely packed appearance for over a week after emigrating, before finally becoming flattened. On both substrates the emigrated cells failed to reproduce fully the appearances found in healing tracheal wounds in vivo.
It is concluded that the appearance and behaviour of differentiated cells is determined to a considerable degree by the physical nature of their substrate.