Highly efficient EIAV-mediated in utero gene transfer and expression in the major muscle groups affected by Duchenne muscular dystrophy.

Gene therapy for Duchenne muscular dystrophy has so far not been successful because of the difficulty in achieving efficient and permanent gene transfer to the large number of affected muscles and the development of immune reactions against vector and transgenic protein. In addition, the prenatal onset of disease complicates postnatal gene therapy. We have therefore proposed a fetal approach to overcome these barriers. We have applied beta-galactosidase expressing equine infectious anaemia virus (EIAV) lentiviruses pseudotyped with VSV-G by single or combined injection via different routes to the MF1 mouse fetus on day 15 of gestation and describe substantial gene delivery to the musculature. Highly efficient gene transfer to skeletal muscles, including the diaphragm and intercostal muscles, as well as to cardiac myocytes was observed and gene expression persisted for at least 15 months after administration of this integrating vector. These findings support the concept of in utero gene delivery for therapeutic and long-term prevention/correction of muscular dystrophies and pave the way for a future application in the clinic.

Marbles mutants: uncoupling cell determination and nuclear migration in the developing Drosophila eye.

Morphogenesis of a multicellular structure requires not only that cells are specified to express particular gene products, but also that cells move to adopt characteristic shapes and positions. Little is known about how these two aspects of morphogenesis are coordinated. The developing Drosophila compound eye is a monolayer, in which cells are suspended between apical and basal membranes and assemble sequentially into hundreds of unit eyes, or facets, guided by a series of cell interactions. As cells are determined to join the facet, their nuclei and cell bodies rise apically and then settle into position in the cell group. The final nuclear positions determine the shape of the individual cells. We have identified a Drosophila gene called marbles which is required for the apical nuclear migrations that accompany cell determination during eye development. In marbles mutant eyes, the sequence of cell specification that leads to the formation of facets occurs almost normally despite the failure of nuclear migration in many cells. The marbles mutant phenotype reveals that during Drosophila eye development cell determination does not require nuclear migration.