ABSTRACT
We have characterized the mutation in a feline model of DMD that selectively eliminates expression of the muscle and Purkinje neuronal dystrophin isoforms. The cortical neuronal isoform was expressed at a detectable level in skeletal muscle in the absence of the muscle promoter and levels of PCR products representing cortical neuronal-type transcripts in dystrophic muscle were comparable to those of normal feline skeletal muscle. Although localized at the sarcolemma, cortical neuronal dystrophin apparently failed to protect skeletal muscle. Neuronal transcripts could not be amplified from feline heart, indicating that these promoters are not active in this tissue in the cat.
Subject(s)
Dystrophin/genetics , Gene Deletion , Muscular Dystrophy, Animal/genetics , Promoter Regions, Genetic , Animals , Base Sequence , Blotting, Northern , Blotting, Southern , Blotting, Western , Cats , Dystrophin/metabolism , Image Processing, Computer-Assisted , Immunohistochemistry , Isomerism , Male , Molecular Sequence Data , Muscles/metabolism , Muscles/ultrastructure , Polymerase Chain Reaction , Sarcolemma/metabolism , Transcription, GeneticABSTRACT
Monocular enucleation of hamsters on the day of birth caused an increase in cellular degeneration and a corresponding loss of cells in the dorsal lateral geniculate nucleus contralateral to the enucleation over the first 12 postnatal days. The superficial layers of the contralateral superior colliculus showed a similar increase in cell degeneration, except rostrally where the remaining ipsilateral projection is found. No changes in degeneration were found in either the ipsi- or contralateral ventral lateral geniculate nuclei, the intermediate and deep layers of the superior colliculus, or in the dorsal lateral geniculate and superficial superior colliculus ipsilateral to the enucleation, even though all were denervated to some degree. The disparities in the incidence of degenerating cells normally seen in the central and peripheral regions of the superior colliculus and dorsal lateral geniculate were preserved following the monocular enucleation. The incidence of degenerating cells in early development correlates well with known alterations in adult cell number. Only major denervations of retinal targets appear to be adequate to produce measurable changes in early cellular degeneration.
