Cartilage morphogenesis in vitro.

The morphogenetic capacity of prechondrogenic mesenchyme from two developmentally distinct sources was investigated in high density micromass cultures. We confirmed an earlier report (Weiss & Moscona, 1958) that scleral mesenchyme formed cartilage sheets whilst limb bud mesenchyme formed distinct cartilage nodules. It was thus suggested by these authors that this morphogenesis was tissue type specific. However, by varying cell density at inoculation (which controls cell configuration) and by varying the relative amount of prechondrogenic mesenchyme present in cultures we found that dramatic changes in morphogenesis could be brought about. Viewed in these terms we suggest that cartilage morphogenesis in vitro is dependent on cell configuration and the presence of non-chondrogenic cell types and hence is not necessarily a function of an intrinsic morphogenetic potential of the constituent cells.