Basal lamina molecules are concentrated in myogenic regions of the mouse limb bud.
Molecular components of basal lamina, such as laminin, stimulate the differentiation of skeletal muscle cells in culture, while interstitial matrix components such as fibronectin are inhibitory. However, the role of extracellular matrix (ECM) molecules in muscle cell differentiation in the embryo is less well understood. As a first step toward understanding the role of the ECM in embryonic myogenesis, the localization of basal lamina molecules in the mouse limb bud before and during muscle cell differentiation was determined by immunofluorescence. Laminin, collagen type IV and nidogen (entactin) were concentrated in myogenic regions of the limb bud both before and during differentiation of skeletal muscle cells. Punctate immunofluorescence for basal lamina molecules was concentrated in dorsal and ventral premuscle and muscle masses, when compared with other regions of limb mesenchyme. In contrast, immunofluorescence for fibronectin, an interstitial extracellular matrix molecule, was decreased in premuscle and muscle masses. These results suggest that basal lamina components play an important stimulatory role in early stages of skeletal muscle differentiation in the developing mouse limb bud.
Godfrey
E W
EW
Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee 53225, USA. egodfrey@mcw.edu
Gradall
K S
KS
D000818:Animals; D001485:Basement Membrane / Q000196:embryology / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006614:Hindlimb / Q000196:embryology; D007797:Laminin / Q000378:metabolism; D018878:Limb Buds / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D018482:Muscle, Skeletal / Q000196:embryology / Q000378:metabolism*; D011247:Pregnancy; D011817:Rabbits
D016326:Extracellular Matrix Proteins; D007797:Laminin; D008562:Membrane Glycoproteins; C029967:nidogen; D003094:Collagen