G. Steffens et al., SEGMENTAL DIFFERENTIATION PROCESSES IN EMBRYONIC MUSCLE DEVELOPMENT OF THE GRASSHOPPER, Roux's archives of developmental biology, 204(7-8), 1995, pp. 453-464
To analyse segmental differentiation processes in muscle development,
we studied the embryogenesis of the ventral body wall muscles in thora
cic and abdominal segments of the grasshopper Schistocerca gregaria at
the identified cell level. We visualized differentiating muscle pione
er and muscle precursor cells by staining with a muscle-specific monoc
lonal antibody and with rhodamine-coupled phalloidin. Our results show
that a similar pattern of serially reiterated early muscle pioneers i
s initially established in all segments. Subsequently, two major segme
ntal differentiation processes occur. First, segment-specific sets of
additional, later differentiating muscle pioneers are generated de nov
o. Second, segment-specific sets of existing early muscle precursors a
re eliminated through atrophy and eventual loss. These events have con
sequences for matching homonomy of muscles and their innervating moton
eurons. Taken together, these processes in the embryo, in concert with
postembryonic differentiation events, play critical roles in shaping
the highly specialized muscular structures of the mature animal.