Lymphocytes from 5 clinically normal lambs and 5 lambs affected with ovine hereditary chondrodysplasia (spider syndrome) were cultured, G-banded, and karyotyped. Fifty metaphase karyotypes and one heterogram were evaluated for chromosome number and morphologic features. All lambs had normal diploid (2n) chromosome numbers of 54,XX or 54,XY, and there were no apparent differences in the morphologic features of the chromosomes.

Holstein cow 1 was examined because of skin fragility and delayed healing of skin wounds, which were markedly exacerbated around the time of parturition. A skin biopsy sample was obtained, and light microscopy revealed irregular deposition of thin collagen fibers in a dermal matrix. Although diffuse inflammation did not occur, the number of plump fibroblasts was increased. Electron microscopy revealed poor construction of collagen fibrils in the dermal matrix. Biochemical analysis of the dermis revealed a normal amount of collagen and uronic acid, but sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveled an increased proportion of soluble alpha-, beta-, and gamma-collagen chains of normal molecular weights. Neither procollagen nor its intermediates devoid of amino- or carboxy-terminal extension peptide were observed. Dermal collagen from cow 1 was more soluble in a neutral salt solvent, 0.5M acetic acid, and the acid containing pepsin than was dermal collagen from healthy cow 2. The peptic digestion profile of dermis from cow 1 revealed a lowered degree of intermolecular cross-linking and destabilization of helical structure in the dermis collagen. The extrahelical peptic cleavage of collagen before cyanogen bromide digestion resulted in release of more fragments derived from carboxy-terminal part of alpha1 chains in dermis of cow 1 than in dermis of healthy cow 2.