Specification of jaw muscle identity in zebrafish: correlation with engrailed-homeoprotein expression.
Molecules that determine the specific features of individual muscles in vertebrates are unknown. Antibody labeling studies described here revealed a molecular difference among muscles in the zebrafish head, in that two functionally related jaw muscles (the levator arcus palatini and the dilator operculi), and not other head muscles, expressed engrailed-homeodomain proteins. Expression began in mesoderm-derived muscle-precursor cells in the paraxial mesenchyme and continued during muscle morphogenesis and differentiation. Growth cones of trigeminal motoneurons that innervate these muscles associated with the precursors within a few hours of the time they began to express engrailed. It is proposed that the engrailed proteins in these cells establish muscle identity and neuromuscular target recognition.
Hatta
K
K
Institute of Neuroscience, University of Oregon, Eugene 97403.
Schilling
T F
TF
BreMiller
R A
RA
Kimmel
C B
CB
D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000097:blood*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D007568:Jaw / Q000196:embryology*; D009024:Morphogenesis; D009046:Motor Neurons / Q000166:cytology; D009132:Muscles / Q000196:embryology* / Q000294:innervation / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology*
D004268:DNA-Binding Proteins