High impact information on fas

• The double mutant shows a clear defect in growth cone guidance; for example, the RP1 growth cone (normally fas I positive) does not follow its normal path across the commissure [1].
• We have identified protein-null mutations in the fasciclin I (fas I) gene, and show that these mutants are viable and do not display gross defects in nervous system morphogenesis [1].
• We propose that fas is required for hkb-dependent signaling events that coordinate internalization [2].
• In situ hybridization demonstrated that fas transcripts are expressed throughout the embryo but they are in relatively high concentrations in the lateral ectoderm, from which the peripheral nervous system delaminates and in the CNS [3].
• In the peripheral nervous system (PNS) of fas mutants, neurons fail to delaminate from the ectodermal epithelium; in the central nervous system (CNS), the positions of neuronal cell bodies and glial cells are abnormal and normal axonal pathways do not form [3].

Biological context of fas

• In embryos mutant for hückebein (hkb), which encodes a transcription factor, or faint sausage (fas), which encodes a cell adhesion molecule, internalization begins in the center of the primordia, and completely aberrant tubes are formed [2].
• In contrast, the number of branches and varicosities are reduced in larvae that overexpress the Fas I molecule resulting from additional copies of the fas I transgene in P(fas I+) or the chromosome duplication in Dp(fas I) mutants [4].
• faint sausage encodes a novel extracellular protein of the immunoglobulin superfamily required for cell migration and the establishment of normal axonal pathways in the Drosophila nervous system [3].

Anatomical context of fas

• The voltage-clamp analysis of excitatory junctional currents (ejcs) at the neuromuscular junction indicates that the amplitude of ejcs is reduced in fas ITE, but increased in P(fas I+) and Dp(fas I) compared to that in wild-type larvae [4].
• We conclude that fas encodes a protein that, in the developing nervous system, is present on the surface of neurons and is essential for nerve cell migration and the establishment of axonal pathways [3].
• Sp3 regulates fas expression in lung epithelial cells [5].

Analytical, diagnostic and therapeutic context of fas

• Sequence analysis of fas cDNAs revealed that the fas protein product has characteristics of an extracellular protein and that it is a novel member of the immunoglobulin (Ig) superfamily [3].

References