Collagen synthesis by cell lines derived from Mov-13 mouse embryos which have a lethal mutation in the collagen alpha...

Mouse embryos homozygous for the Mov-13 mutation produce no collagen I, owing to transcriptional blockage of the collagen alpha 1(I) gene by a retroviral insert. Fibroblast-like cell lines derived from these embryos were compared with similar lines derived from heterozygous and wild-type embryos with respect to the total amounts, and types, of collagen synthesized. Total collagen synthesized by either cloned or uncloned cell lines correlated with their genotype, demonstrating no compensation for absence of collagen I production by an increase in synthesis of other collagen types. Procollagen alpha 2(I) chains were not detected in the homozygous cell lines, demonstrating that these chains do not form homotrimers, nor do they form heterotrimers with alpha-chains of other collagen types. Procollagen III levels were quantified by radioimmunoassay and found to be similar in all cell lines.