Human skin fibroblasts were cultivated in confluent monolayers, retracting collagen lattices, retracting fibrin lattices and non-retracting fibrin lattices and the expression of messenger RNA specific for the α1 chain of type I procollagen comparatively studied by Northern blot and dot blot hybridization. Two factors contribute to the lower level of procollagen messenger RNA in collagen lattices the retraction and the nature of the fibrillar protein that constitutes the lattices. Fibrin lattices, when they do not retract, make as much collagen and procollagen mRNA as monolayer confluent cells.
