Penn Medicine

Education and Training

Muscle Cell Development and Myofibril Assembly

During vertebrate embryogenesis, skeletal muscle cell differentiation is coordinated, spatially and temporally, with the development of the embryonic body plan by cell-cell signaling between the axially-located neural tube and newly forming somites. These interactions result in an ordered series of changes in gene expression from the synthesis of myogenic regulatory factors, synthesis and assembly of muscle proteins into myofibrils and isoform changes of the major contractile proteins. Much less is known about the developmental steps leading to the differentiation of cardiac muscle cells.

Myofibrillogenesis, one of the major steps in the early development of skeletal and cardiac muscles, occurs in an orchestrated series of events involving the formation of actin and myosin filaments, their assembly into an interdigitating array and their interaction with cross-linking proteins to form the sarcomere. We still know very little about the roles played by individual sarcomeric proteins in the assembly of myofibrils. New techniques of molecular biology and genetics combined with advances in biophysical and imaging techniques provide tools for examining this problem that were not possible in the past.

The objective of the graduate training in this program is to use such a multidisciplinary approach combining the techniques of cell biology, biophysics, genetics and molecular biology to discover important steps in the differentiation of precursor cells into skeletal and cardiac muscle cells and the parameters governing the assembly of myofibrils.

The following PMI Members at the University of Pennsylvania are investigating muscle cell development and myofibril assembly:


Pennsylvania Muscle Institute
Perelman School of Medicine University of Pennsylvania
Director: E. Michael Ostap, Ph.D.

700A Clinical Research Building Philadelphia, PA 19104-6085 Phone: (215) 573-9758 Fax: (215) 898-2653