Y. Rosenberghasson et al., A DROSOPHILA DYSTROPHIN-RELATED PROTEIN, MSP-300, IS REQUIRED FOR EMBRYONIC MUSCLE MORPHOGENESIS, Mechanisms of development, 60(1), 1996, pp. 83-94
Proteins from the spectrin superfamily contribute to cell polarity and
shape during the morphogenetic movements that accompany embryogenesis
. Drosophila MSP-300, a member of the spectrin superfamily, is express
ed in somatic, visceral and heart embryonic muscles. Cloning and seque
nce analysis of various spliced forms of MSP-300 reveals functional an
d structural similarities between MSP-300 and vertebrate Dystrophin, t
he product of the Duchenne Muscular Dystrophy gene. The identification
of a strain mutant for the MSP-300 gene is described. Analysis of the
somatic muscle phenotype in MSP-300 mutant embryos suggests that the
protein contributes to the integrity of the somatic and visceral muscl
e tissue during periods of significant morphogenetic change. Functiona
l synergism between MSP-300 and laminin is demonstrated by the analysi
s of the phenotype of embryos mutant for both genes. The enhancement o
f aberrant muscle phenotype in the double mutants suggests a link betw
een MSP-300 and laminin function in mediating proper extension of the
myotube towards the epidermal muscle attachment site. In addition, bot
h genes function to establish gut integrity. In view of the functional
and structural similarities between MSP-300 and Dystrophin, it is pos
tulated that Dystrophin is not only required for proper muscle functio
n in adult life but also contributes to muscle morphogenesis during th
e development of the vertebrate embryo.