Oulu Center to Cell-Matrix Research, Biocenter Oulu, Department of Medical Biochemistry and Molecular Biology, University of Oulu, P. O. Box 5000, 90014, Oulu, Finland.
Overexpression of type XIII collagen molecules with an 83-amino-acid residue in-frame deletion of part of the ectodomain leads to fetal lethality in Col13a1COL2del transgenic mice. We characterize here the functional disturbances in the cardiovascular system of mouse fetuses overexpressing mutant type XIII collagen. Doppler ultrasonography was performed at 12.5 days of gestation on 33 fetuses resulting from heterozygous matings of seven female mice and on 16 fetuses from two matings between heterozygous and wild-type mice. Nine fetuses had atrioventricular valve regurgitation (AVVR), and all of them were transgene-positive. The fetuses with AVVR had a lower outflow mean velocity (Vmean; P