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Embryogenesis of the avian iris sphincter muscle: in vivo and in vitro studies
Author(s) -
Peirone Saverio M.,
SistoDaneo Laura,
Filogamo Guido
Publication year - 1990
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(90)90020-3
Subject(s) - in vivo , embryogenesis , iris (biosensor) , in vitro , biology , sphincter , embryo , microbiology and biotechnology , anatomy , genetics , computer science , computer security , biometrics
The histogenesis of iris sphincter muscle was studied in birds. Chick embryo iris “anlagen”, aged from 3 days (st. 18 H.H.) to hatching, were examined. At the 4th day (st. 24 H.H.), nerve fibers were observed in the mesenchyme of the inferotemporal quadrant of the optic cup near the colobomic fissure. Among the mesenchymal cells, there were cells characterized by AChE activity, presence of desmin filaments, exhibiting ACh receptors, and ultrastructurally similar to the presumptive skeletal myoblasts. One day later (st. 27 H.H.), these myoblasts could be cultivated. The formation of myotubes began between 10 and 12 days. From 9 to 14 days, cells left the anterior epithelium of the iris to give rise to the smooth iris muscle; during this evolution some epithelial cells fused with the myotubes taking part in the histogenesis of striated muscle. The possibility of a neurogenic determination for the iris skeletal muscle is discussed.