Retinal axon guidance at the midline: Chiasmatic misrouting and consequences

2017 ◽  
Vol 77 (7) ◽  
pp. 844-860 ◽  
Author(s):  
Delphine S. Prieur ◽  
Alexandra Rebsam
Keyword(s):  
Axon Guidance ◽  
Retinal Axon

astray, a Zebrafish roundabout Homolog Required for Retinal Axon Guidance

Science ◽  
2001 ◽  
Vol 292 (5516) ◽  
pp. 507-510 ◽  
Author(s):  
C. Fricke ◽  
J.-S. Lee ◽  
S. Geiger-Rudolph ◽  
F. Bonhoeffer ◽  
C.-B. Chien
Keyword(s):  
Axon Guidance ◽  
Retinal Axon

scholarly journals Pax6 modulates intra-retinal axon guidance and fasciculation of retinal ganglion cells during retinogenesis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Soundararajan Lalitha ◽  
Budhaditya Basu ◽  
Suresh Surya ◽  
Vadakkath Meera ◽  
Paul Ann Riya ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Ganglion Cells ◽  
Transcriptome Profiling ◽  
Retinal Ganglion ◽  
Temporal Expression ◽  
Fate Specification ◽  
Extracellular Matrix Molecules ◽  
Coordinated Expression ◽  
Spatio Temporal ◽  
Retinal Axon

Abstract Intra-retinal axon guidance involves a coordinated expression of transcription factors, axon guidance genes, and secretory molecules within the retina. Pax6, the master regulator gene, has a spatio-temporal expression typically restricted till neurogenesis and fate-specification. However, our observation of persistent expression of Pax6 in mature RGCs led us to hypothesize that Pax6 could play a major role in axon guidance after fate specification. Here, we found significant alteration in intra-retinal axon guidance and fasciculation upon knocking out of Pax6 in E15.5 retina. Through unbiased transcriptome profiling between Pax6fl/fl and Pax6−/− retinas, we revealed the mechanistic insight of its role in axon guidance. Our results showed a significant increase in the expression of extracellular matrix molecules and decreased expression of retinal fate specification and neuron projection guidance molecules. Additionally, we found that EphB1 and Sema5B are directly regulated by Pax6 owing to the guidance defects and improper fasciculation of axons. We conclude that Pax6 expression post fate specification of RGCs is necessary for regulating the expression of axon guidance genes and most importantly for maintaining a conducive ECM through which the nascent axons get guided and fasciculate to reach the optic disc.

Specific heparan sulfate structures involved in retinal axon targeting

Development ◽  
2002 ◽  
Vol 129 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Atsushi Irie ◽  
Edwin A. Yates ◽  
Jeremy E. Turnbull ◽  
Christine E. Holt
Keyword(s):  
Heparan Sulfate ◽  
Axon Guidance ◽  
Structural Characteristics ◽  
In Situ Hybridisation ◽  
Optic Tract ◽  
Structural Diversity ◽  
Axon Targeting ◽  
Retinal Axon

Heparan sulfate (HS), a structurally diverse molecule comprising distinct sequences of sulfated disaccharide units, is abundant in the developing brain and binds to axon guidance molecules. Addition of HS to the developing Xenopus optic pathway causes severe targeting errors yet it is not known how the structural diversity of this molecule relates to its role in axon guidance. We have used an in vivo brain assay to identify the structural characteristics of HS that induce aberrant axon targeting. Inhibiting sulfation of endogenous HS with chlorate causes axons to bypass their target, the tectum, and treatment with chemically modified heparins reveals that 2-O- and 6-O-sulfate groups have potent bypass-inducing activity. Experiments with purified heparin saccharides show that bypass-inducing activity correlates with distinct structures, particularly those containing a combination of 2-O- and 6-O-sulfate groups. Taken together the results indicate that specific sequences, rather than gross structural composition, are critical for activity. In situ hybridisation revealed that HS 6-O-sulfotransferase is regionally expressed along the border of the dorsal optic tract whereas 2-O-sulfotransferase is expressed broadly. Our results demonstrate that specific HS sequences are essential for regulating retinotectal axon targeting and suggest that regionalised biosynthesis of specific HS structures is important for guiding axons into the tectum.

scholarly journals Heparan Sulphation Patterns Generated by Specific Heparan Sulfotransferase Enzymes Direct Distinct Aspects of Retinal Axon Guidance at the Optic Chiasm

2006 ◽  
Vol 26 (26) ◽  
pp. 6911-6923 ◽  
Author(s):  
T. Pratt ◽  
C. D. Conway ◽  
N. M. M.- L. Tian ◽  
D. J. Price ◽  
J. O. Mason
Keyword(s):  
Axon Guidance ◽  
Optic Chiasm ◽  
Retinal Axon

scholarly journals Topographically Specific Effects of ELF-1 on Retinal Axon Guidance In Vitro and Retinal Axon Mapping In Vivo

Cell ◽  
1996 ◽  
Vol 86 (5) ◽  
pp. 755-766 ◽  
Author(s):  
Masaru Nakamoto ◽  
Hwai-Jong Cheng ◽  
Glenn C Friedman ◽  
Todd McLaughlin ◽  
Michael J Hansen ◽  
...  
Keyword(s):  
Axon Guidance ◽  
Specific Effects ◽  
Retinal Axon

scholarly journals Xenopus sonic hedgehog is involved in retinal axon guidance

2008 ◽  
Vol 319 (2) ◽  
pp. 540
Author(s):  
Andrea R. Morris ◽  
Laura Carlson ◽  
Matthew Mansh ◽  
Helen Kinsman
Keyword(s):  
Axon Guidance ◽  
Sonic Hedgehog ◽  
Retinal Axon
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