Triggering of the cell cycle in an organized tissue <i>In vitro</i>

Abstract

Abstract The rabbit lens can be maintained in culture under conditions which retain the block to proliferation characteristic of many of the cells in the normal tissue in vivo . Proliferation and cell migration subsequently can be triggered at will by the addition of serum to the medium. Serum is not required throughout the whole period of culture in order to elicit this response but only during an initial period which ends prior to the onset of both DNA synthesis and mitosis. The duration of this period of serum‐dependency is specifically related to the location (and hence the state of organization) of the cells within the epithelial layer. Some of the characteristics of the serum factors which promote these reactions and the conditions of culture which affect their activity are reported.