Effect of Emb-9 and Let-2 Mutations on the Proper Assembly of Basement Membranes and on the Morphology of Body Wall Muscle Cells in Caenorhabditis Elegans

Date of Graduation

Summer 2003


Master of Science in Cell and Molecular Biology


Biomedical Sciences

Committee Chair

Colette Witkowski


Collagen type IV is one of the most abundant components of the basement membrane composed of two α1 chains and one α2 chain secreted into the BM between muscle cells and the hypodermis early in embryogenesis. Worms homozygous for specific let-2 or emb-9 mutations show intracellular accumulation of the α2 of α1 chain, respectively, and undergo degeneration of muscle causing phenotypes ranging from mild to severe. The objective of this research was to analyze the effect of collagen type IV mutations on the shape and organization of body wall muscle cells. Transgenic strains were generated by co-microinjection of plasmid DNA containing the marker gene rol-6 and green fluorescent protein (GFP) into the gona of wild type animals heterozygous for the let-2 and emb-9 genes. Transgenic worms showed GFP expression outlining body wall muscle cells due to the presence of a myo-3 promoter, and β1 integrin secretion signal/transmembrane domain. Analysis of transgenic strains demonstrated that mutations in either the α1 or α2 chains of collagen type IV cause a change in shape and organization of muscle cells. Immunofluorescence analysis of all transgenic strains showed a correlation between the change in position of muscle cells and the appearance of herniations. These results further extend data suggesting that collagen type IV is essential for embryonic development.

Subject Categories

Medical Molecular Biology


© Libia Chandler