Limits...
Neurolin Ig domain 2 participates in retinal axon guidance and Ig domains 1 and 3 in fasciculation.

Leppert CA, Diekmann H, Paul C, Laessing U, Marx M, Bastmeyer M, Stuermer CA - J. Cell Biol. (1999)

Bottom Line: Repeated intraocular injections of a mAb against Ig domain 2 disturb the disk-directed growth: axons grow in aberrant routes and fail to reach the optic disk, but remain fasciculated. mAbs against Ig domains 1 and 3 disturb the formation of tight fascicles. mAb against Ig domain 2 significantly increases the incidence of growth cone departure from the disk-oriented fascicle track, while mAbs against Ig domains 1 and 3 do not.This was demonstrated by time-lapse videorecording of labeled growth cones.Thus, Ig domain 2 of neurolin is apparently essential for growth cone guidance towards the disk, presumably by being part of a receptor (or complex) for an axon guidance component.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.

ABSTRACT
The optic disk-directed growth of retinal ganglion cell axons is markedly disturbed in the presence of polyclonal antineurolin antibodies, which mildly affect fasciculation (Ott, H., M. Bastmeyer, and C.A.O. Stuermer, 1998. J. Neurosci. 18:3363-3372). New monoclonal antibodies (mAbs) against goldfish neurolin, an immunoglobulin (Ig) superfamily cell adhesion/recognition molecule with five Ig domains, were generated to assign function (guidance versus fasciculation) to specific Ig domains. By their ability or failure to recognize Chinese hamster ovary cells expressing recombinant neurolin with deletions of defined Ig domains, mAbs were identified as being directed against Ig domains 1, 2, or 3, respectively. Repeated intraocular injections of a mAb against Ig domain 2 disturb the disk-directed growth: axons grow in aberrant routes and fail to reach the optic disk, but remain fasciculated. mAbs against Ig domains 1 and 3 disturb the formation of tight fascicles. mAb against Ig domain 2 significantly increases the incidence of growth cone departure from the disk-oriented fascicle track, while mAbs against Ig domains 1 and 3 do not. This was demonstrated by time-lapse videorecording of labeled growth cones. Thus, Ig domain 2 of neurolin is apparently essential for growth cone guidance towards the disk, presumably by being part of a receptor (or complex) for an axon guidance component.

Show MeSH

Related in: MedlinePlus

Ig domain 2 of neurolin participates in axon guidance  to the optic disk. Wholemount of a retina injected with mAb  N518 against Ig domain 2. The dorsal inner area where pathway  mistakes are most frequent is indicated by the dashed semi-circle.  Occasional aberrant fascicles in the peripheral retina are marked  by arrows. Dorsal retina is up and temporal to the right. Bar, 1 mm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2132892&req=5

Figure 4: Ig domain 2 of neurolin participates in axon guidance to the optic disk. Wholemount of a retina injected with mAb N518 against Ig domain 2. The dorsal inner area where pathway mistakes are most frequent is indicated by the dashed semi-circle. Occasional aberrant fascicles in the peripheral retina are marked by arrows. Dorsal retina is up and temporal to the right. Bar, 1 mm.

Mentions: After injections of mAb N518, misrouted axons were abundant in all 16 retinae. Axons in aberrant routes occurred from nasal over dorsal to temporal retinal aspects, and were most abundant in the inner retinal aspect, i.e., when axons had covered roughly 50% of their path from the periphery to the optic disk (Fig. 4). Axons that were previously associated with other axons in distinct fascicles no longer preserved this order. They formed new subfascicles with more distant axons and traveled in loops and other irregular pathways (Figs. 4 and 5). Quite frequently, axons that left their fascicle of origin grew away from the disk, turned again, associated with bundles of other misoriented or disk-oriented fascicles, or ended somewhere between other axon bundles (Fig. 5). Despite their errant path, a fraction of axons reached the optic disk (Figs. 4 and 5 A), yet others appeared to get lost (Fig. 5, A, B, and D). Most axons were able to form tight fascicles over the first 50% of the path from the margin to the disk, but even here subfascicles separated from the major fascicle (Fig. 4). These subfascicles then often followed curvy routes and crossed other fascicles until they merged again with one of the prominent bundles. Yet, as they approached the inner 50% of the retina, most axons apparently lost their ability to travel along disk-directed fascicles (Fig. 5). This suggests that many young growing axons in mAb N518-treated retinae fail to respond to guidance cues that they normally would perceive.


Neurolin Ig domain 2 participates in retinal axon guidance and Ig domains 1 and 3 in fasciculation.

Leppert CA, Diekmann H, Paul C, Laessing U, Marx M, Bastmeyer M, Stuermer CA - J. Cell Biol. (1999)

Ig domain 2 of neurolin participates in axon guidance  to the optic disk. Wholemount of a retina injected with mAb  N518 against Ig domain 2. The dorsal inner area where pathway  mistakes are most frequent is indicated by the dashed semi-circle.  Occasional aberrant fascicles in the peripheral retina are marked  by arrows. Dorsal retina is up and temporal to the right. Bar, 1 mm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2132892&req=5

Figure 4: Ig domain 2 of neurolin participates in axon guidance to the optic disk. Wholemount of a retina injected with mAb N518 against Ig domain 2. The dorsal inner area where pathway mistakes are most frequent is indicated by the dashed semi-circle. Occasional aberrant fascicles in the peripheral retina are marked by arrows. Dorsal retina is up and temporal to the right. Bar, 1 mm.
Mentions: After injections of mAb N518, misrouted axons were abundant in all 16 retinae. Axons in aberrant routes occurred from nasal over dorsal to temporal retinal aspects, and were most abundant in the inner retinal aspect, i.e., when axons had covered roughly 50% of their path from the periphery to the optic disk (Fig. 4). Axons that were previously associated with other axons in distinct fascicles no longer preserved this order. They formed new subfascicles with more distant axons and traveled in loops and other irregular pathways (Figs. 4 and 5). Quite frequently, axons that left their fascicle of origin grew away from the disk, turned again, associated with bundles of other misoriented or disk-oriented fascicles, or ended somewhere between other axon bundles (Fig. 5). Despite their errant path, a fraction of axons reached the optic disk (Figs. 4 and 5 A), yet others appeared to get lost (Fig. 5, A, B, and D). Most axons were able to form tight fascicles over the first 50% of the path from the margin to the disk, but even here subfascicles separated from the major fascicle (Fig. 4). These subfascicles then often followed curvy routes and crossed other fascicles until they merged again with one of the prominent bundles. Yet, as they approached the inner 50% of the retina, most axons apparently lost their ability to travel along disk-directed fascicles (Fig. 5). This suggests that many young growing axons in mAb N518-treated retinae fail to respond to guidance cues that they normally would perceive.

Bottom Line: Repeated intraocular injections of a mAb against Ig domain 2 disturb the disk-directed growth: axons grow in aberrant routes and fail to reach the optic disk, but remain fasciculated. mAbs against Ig domains 1 and 3 disturb the formation of tight fascicles. mAb against Ig domain 2 significantly increases the incidence of growth cone departure from the disk-oriented fascicle track, while mAbs against Ig domains 1 and 3 do not.This was demonstrated by time-lapse videorecording of labeled growth cones.Thus, Ig domain 2 of neurolin is apparently essential for growth cone guidance towards the disk, presumably by being part of a receptor (or complex) for an axon guidance component.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.

ABSTRACT
The optic disk-directed growth of retinal ganglion cell axons is markedly disturbed in the presence of polyclonal antineurolin antibodies, which mildly affect fasciculation (Ott, H., M. Bastmeyer, and C.A.O. Stuermer, 1998. J. Neurosci. 18:3363-3372). New monoclonal antibodies (mAbs) against goldfish neurolin, an immunoglobulin (Ig) superfamily cell adhesion/recognition molecule with five Ig domains, were generated to assign function (guidance versus fasciculation) to specific Ig domains. By their ability or failure to recognize Chinese hamster ovary cells expressing recombinant neurolin with deletions of defined Ig domains, mAbs were identified as being directed against Ig domains 1, 2, or 3, respectively. Repeated intraocular injections of a mAb against Ig domain 2 disturb the disk-directed growth: axons grow in aberrant routes and fail to reach the optic disk, but remain fasciculated. mAbs against Ig domains 1 and 3 disturb the formation of tight fascicles. mAb against Ig domain 2 significantly increases the incidence of growth cone departure from the disk-oriented fascicle track, while mAbs against Ig domains 1 and 3 do not. This was demonstrated by time-lapse videorecording of labeled growth cones. Thus, Ig domain 2 of neurolin is apparently essential for growth cone guidance towards the disk, presumably by being part of a receptor (or complex) for an axon guidance component.

Show MeSH
Related in: MedlinePlus