TY - JOUR
T1 - Different isoforms of fasciclin II are expressed by a subset of developing olfactory receptor neurons and by olfactory-nerve glial cells during formation of glomeruli in the moth Manduca sexta
AU - Higgins, M. R.
AU - Gibson, N. J.
AU - Eckholdt, P. A.
AU - Nighorn, A.
AU - Copenhaver, P. F.
AU - Nardi, J.
AU - Tolbert, L. P.
N1 - Funding Information:
We thank Patricia Jansma, M.S., for technical assistance in developing and testing immunocytochemistry protocols and for overseeing the A.R.L. Division of Neurobiology’s Microscopy Facility; Amit Pandy and Nirav Merchant, M.S., for developing the software for 3-D reconstructions; Terrill Yuhas for technical assistance in the Division’s Image Analysis Facility; Dr. A. A. Osman and Zenzele Mpofu for rearing Manduca sexta; and Andrew Dacks, a graduate student in the University’s Graduate Program in Insect Science, and Jose Aguirre, an undergraduate in the University of Arizona’s NIH Minority Health Disparities Summer Research Opportunities program, for augmenting the number of preparations examined with the antibody against GPI-MFas II and helpful discussions of their findings. This research was supported by NIH Grants DC04598 (to L.P.T.) and NS34439 (to P.F.C.).
PY - 2002/4/1
Y1 - 2002/4/1
N2 - During development of the primary olfactory projection, olfactory receptor axons must sort by odor specificity and seek particular sites in the brain in which to create odor-specific glomeruli. In the moth Manduca sexta, we showed previously that fasciclin II, a cell adhesion molecule in the immunoglobulin superfamily, is expressed by the axons of a subset of olfactory receptor neurons during development and that, in a specialized glia-rich "sorting zone," these axons segregate from nonfasciclin II-expressing axons before entering the neuropil of the glomerular layer. The segregation into fasciclin II-positive fascicles is dependent on the presence of the glial cells in the sorting zone. Here, we explore the expression patterns for different isoforms of Manduca fasciclin II in the developing olfactory system. We find that olfactory receptor axons express transmembrane fasciclin II during the period of axonal ingrowth and glomerulus development. Fascicles of TM-fasciclin II+ axons target certain glomeruli and avoid others, such as the sexually dimorphic glomeruli. These results suggest that TM-fasciclin II may play a role in the sorting and guidance of the axons. GPI-linked forms of fasciclin II are expressed weakly by glial cells associated with the receptor axons before they reach the sorting zone, but not by sorting-zone glia. GPI-fasciclin II may, therefore, be involved in axon-glia interactions related to stabilization of axons in the nerve, but probably not related to sorting.
AB - During development of the primary olfactory projection, olfactory receptor axons must sort by odor specificity and seek particular sites in the brain in which to create odor-specific glomeruli. In the moth Manduca sexta, we showed previously that fasciclin II, a cell adhesion molecule in the immunoglobulin superfamily, is expressed by the axons of a subset of olfactory receptor neurons during development and that, in a specialized glia-rich "sorting zone," these axons segregate from nonfasciclin II-expressing axons before entering the neuropil of the glomerular layer. The segregation into fasciclin II-positive fascicles is dependent on the presence of the glial cells in the sorting zone. Here, we explore the expression patterns for different isoforms of Manduca fasciclin II in the developing olfactory system. We find that olfactory receptor axons express transmembrane fasciclin II during the period of axonal ingrowth and glomerulus development. Fascicles of TM-fasciclin II+ axons target certain glomeruli and avoid others, such as the sexually dimorphic glomeruli. These results suggest that TM-fasciclin II may play a role in the sorting and guidance of the axons. GPI-linked forms of fasciclin II are expressed weakly by glial cells associated with the receptor axons before they reach the sorting zone, but not by sorting-zone glia. GPI-fasciclin II may, therefore, be involved in axon-glia interactions related to stabilization of axons in the nerve, but probably not related to sorting.
UR - http://www.scopus.com/inward/record.url?scp=0036534439&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036534439&partnerID=8YFLogxK
U2 - 10.1006/dbio.2002.0583
DO - 10.1006/dbio.2002.0583
M3 - Article
C2 - 11900464
AN - SCOPUS:0036534439
SN - 0012-1606
VL - 244
SP - 134
EP - 154
JO - Developmental Biology
JF - Developmental Biology
IS - 1
ER -