S. Hu et al., MIDLINE FASCICLIN - A DROSOPHILA FASCICLIN-I-RELATED MEMBRANE-PROTEINLOCALIZED TO THE CNS MIDLINE CELLS AND TRACHEA, Journal of neurobiology, 35(1), 1998, pp. 77-93
Drosophila Fasciclin I is the prototype of a family of vertebrate and
invertebrate proteins that mediate cell adhesion and signaling. The mi
dline fasciclin gene encodes a second Drosophila member of the Fascicl
in I family. Midline Fasciclin largely consists of four 150 amino acid
repeats characteristic of the Fasciclin I family of proteins. Immunos
taining and biochemical analysis using Midline Fasciclin antibodies in
dicates that it is a membrane-associated protein, although the sequenc
e does not reveal a transmembrane domain. The gene is expressed in a d
ynamic fashion during embryogenesis in the blastoderm, central nervous
system midline cells, and trachea, suggesting it plays multiple devel
opmental roles. Protein localization studies indicate that Midline Fas
ciclin is found within cell bodies of midline neurons and glia, and on
midline axons. Initial cellular analysis of a midline fasciclin loss-
of-function mutation reveals only weak defects in axonogenesis. Howeve
r, embryos mutant for both midline fasciclin and the abelson nonrecept
or tyrosine kinase, show more severe defects in axonogenesis that rese
mble fasciclin I abelson double mutant phenotypes. (C) 1998 John Wiley
& Sons, Inc.