THE CHICKEN ALPHA-1(XI) COLLAGEN GENE IS WIDELY EXPRESSED IN EMBRYONIC-TISSUES

Complementary DNA and genomic DNA clones corresponding to the chicken alpha1(XI) collagen gene were isolated and characterized. These recombinant DNA clones covered 2667 base pairs of the mRNA and encode 624 amino acids of the triple helical region plus the entire carboxyl-terminal propeptide. Northern blot analysis showed a major band of approximately 6.5 kilobases and a minor band of approximately 7.5 kilobases. A combination of Northern blot and in situ hybridization analyses showed that, in addition to its presence in cartilage, this mRNA also is present in a wide variety of chicken noncartilaginous embryonic tissues including brain, heart, skeletal muscle, calvaria, and skin, but was not detected in liver. Type II collagen mRNA has also been detected at low levels in these same tissues. Also, similar to the mRNA for the alpha1 chain for type II collagen, the alpha1(XI) collagen mRNA is detected in limb mesenchyme prior to condensation and differentiation of the core mesenchyme into cartilage.