1
|
Panza P, Sitko AA, Maischein HM, Koch I, Flötenmeyer M, Wright GJ, Mandai K, Mason CA, Söllner C. The LRR receptor Islr2 is required for retinal axon routing at the vertebrate optic chiasm. Neural Dev 2015; 10:23. [PMID: 26492970 PMCID: PMC4618557 DOI: 10.1186/s13064-015-0050-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 10/01/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the visual system of most binocular vertebrates, the axons of retinal ganglion cells (RGCs) diverge at the diencephalic midline and extend to targets on both ipsi- and contralateral sides of the brain. While a molecular mechanism explaining ipsilateral guidance decisions has been characterized, less is known of how RGC axons cross the midline. RESULTS Here, we took advantage of the zebrafish, in which all RGC axons project contralaterally at the optic chiasm, to characterize Islr2 as an RGC receptor required for complete retinal axon midline crossing. We used a systematic extracellular protein-protein interaction screening assay to identify two Vasorin paralogs, Vasna and Vasnb, as specific Islr2 ligands. Antibodies against Vasna and Vasnb reveal cellular populations surrounding the retinal axon pathway, suggesting the involvement of these proteins in guidance decisions made by axons of the optic nerve. Specifically, Vasnb marks the membranes of a cellular barricade located anteriorly to the optic chiasm, a structure termed the "glial knot" in higher vertebrates. Loss of function mutations in either vasorin paralog, individually or combined, however, do not exhibit an overt retinal axon projection phenotype, suggesting that additional midline factors, acting either independently or redundantly, compensate for their loss. Analysis of Islr2 knockout mice supports a scenario in which Islr2 controls the coherence of RGC axons through the ventral midline and optic tract. CONCLUSIONS Although stereotypic guidance of RGC axons at the vertebrate optic chiasm is controlled by multiple, redundant mechanisms, and despite the differences in ventral diencephalic tissue architecture, we identify a novel role for the LRR receptor Islr2 in ensuring proper axon navigation at the optic chiasm of both zebrafish and mouse.
Collapse
Affiliation(s)
- Paolo Panza
- Max-Planck-Institut für Entwicklungsbiologie, Abteilung Genetik, Spemannstraße 35, 72076, Tübingen, Germany.
| | - Austen A Sitko
- Department of Neuroscience, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York, NY, 10032, USA
| | - Hans-Martin Maischein
- Max-Planck-Institut für Entwicklungsbiologie, Abteilung Genetik, Spemannstraße 35, 72076, Tübingen, Germany.,Present address: Max-Planck-Institut für Herz- und Lungenforschung, Abteilung Genetik der Entwicklung, Ludwigstraße 43, 61231, Bad Nauheim, Germany
| | - Iris Koch
- Max-Planck-Institut für Entwicklungsbiologie, Elektronenmikroskopie, Spemannstraße 35, 72076, Tübingen, Germany
| | - Matthias Flötenmeyer
- Max-Planck-Institut für Entwicklungsbiologie, Elektronenmikroskopie, Spemannstraße 35, 72076, Tübingen, Germany
| | - Gavin J Wright
- Wellcome Trust Sanger Institute, Cell Surface Signalling Laboratory, Hinxton, Cambridge, CB10 1HH, UK
| | - Kenji Mandai
- Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan
| | - Carol A Mason
- Department of Pathology & Cell Biology, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York, NY, 10032, USA.,Department of Neuroscience, Columbia University, College of Physicians and Surgeons, 630 West 168th Street, New York, NY, 10032, USA
| | - Christian Söllner
- Max-Planck-Institut für Entwicklungsbiologie, Abteilung Genetik, Spemannstraße 35, 72076, Tübingen, Germany
| |
Collapse
|
2
|
Mandai K, Guo T, Hillaire CS, Meabon JS, Kanning KC, Bothwell M, Ginty DD. LIG family receptor tyrosine kinase-associated proteins modulate growth factor signals during neural development. Neuron 2009; 63:614-27. [PMID: 19755105 PMCID: PMC2758028 DOI: 10.1016/j.neuron.2009.07.031] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Revised: 06/04/2009] [Accepted: 07/25/2009] [Indexed: 01/19/2023]
Abstract
Genome-wide screens were performed to identify transmembrane proteins that mediate axonal growth, guidance and target field innervation of somatosensory neurons. One gene, Linx (alias Islr2), encoding a leucine-rich repeat and immunoglobulin (LIG) family protein, is expressed in a subset of developing sensory and motor neurons. Domain and genomic structures of Linx and other LIG family members suggest that they are evolutionarily related to Trk receptor tyrosine kinases (RTKs). Several LIGs, including Linx, are expressed in subsets of somatosensory and motor neurons, and select members interact with TrkA and Ret RTKs. Moreover, axonal projection defects in mice harboring a null mutation in Linx resemble those in mice lacking Ngf, TrkA, and Ret. In addition, Linx modulates NGF-TrkA- and GDNF-GFRalpha1/Ret-mediated axonal extension in cultured sensory and motor neurons, respectively. These findings show that LIGs physically interact with RTKs and modulate their activities to control axonal extension, guidance and branching.
Collapse
Affiliation(s)
- Kenji Mandai
- The Solomon H. Snyder Department of Neuroscience, The Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, PCTB 1015, Baltimore, MD 21205, USA
| | - Ting Guo
- The Solomon H. Snyder Department of Neuroscience, The Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, PCTB 1015, Baltimore, MD 21205, USA
| | - Coryse St. Hillaire
- The Solomon H. Snyder Department of Neuroscience, The Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, PCTB 1015, Baltimore, MD 21205, USA
| | - James S. Meabon
- Department of Physiology and Biophysics, Box 357290, University of Washington, School of Medicine, Seattle, WA 98195, USA
| | - Kevin C. Kanning
- Department of Physiology and Biophysics, Box 357290, University of Washington, School of Medicine, Seattle, WA 98195, USA
| | - Mark Bothwell
- Department of Physiology and Biophysics, Box 357290, University of Washington, School of Medicine, Seattle, WA 98195, USA
| | - David D. Ginty
- The Solomon H. Snyder Department of Neuroscience, The Howard Hughes Medical Institute, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, PCTB 1015, Baltimore, MD 21205, USA
| |
Collapse
|
3
|
Lee CJ, Cho EY, Kim SJ. Characterization of tissue-specific mbu-3 gene expression in the mouse central nervous system. BMB Rep 2009; 41:875-80. [PMID: 19123979 DOI: 10.5483/bmbrep.2008.41.12.875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mbu-3 is a novel mouse brain unigene that was identified by digital differential display. In this study, expression of the gene was chased through developmental stages and the protein product was identified in the brain. The cDNA sequence was 3,995-bp long and contained an ORF of 745 AA. Database searches revealed that the chicken SST273 gene containing LRR- and Ig-domain was an mbu-3 orthologue. Tissue specificity for the gene was examined in embryos and in brains at post-natal and adult stages. During the embryonic stages, mbu-3 was localized to the central nervous system in the brain and spinal cord. In the early post-natal stages, the gene was evenly expressed in the brain. However, with aging, expression was confined to specific regions, particularly the hippocampus. The protein was approximately 95 kDa as determined by Western blot analysis of brain extracts.
Collapse
Affiliation(s)
- Chae Jin Lee
- Department of Life Science, Dongguk University, Seoul 100-715, Korea
| | | | | |
Collapse
|
4
|
Homma S, Shimada T, Hikake T, Yaginuma H. Expression pattern of LRR and Ig domain-containing protein (LRRIG protein) in the early mouse embryo. Gene Expr Patterns 2008; 9:1-26. [PMID: 18848646 DOI: 10.1016/j.gep.2008.09.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/10/2008] [Accepted: 09/11/2008] [Indexed: 01/10/2023]
Abstract
The combination of leucine-rich repeat (LRR) and immunoglobulin-like (Ig) domains is found in the domain architecture of the Trk neurotrophin receptor protein. Recently dozens of such proteins simultaneously carrying LRR and Ig domains as the Trk receptors have been identified. Given the significant biological roles of Trk and such newly identified proteins, we have searched the public database for human proteins with LRR and Ig domains (collectively termed the leucine-rich repeat and Ig domain-containing protein, LRRIG protein, in this study), and have analyzed the mRNA expression pattern of mouse orthologs of obtained human LRRIG proteins at embryonic day 10. The list of the LRRIG proteins includes 36 human proteins: four LINGO, three NGL, five SALM, three NLRR, three Pal, two ISLR, three LRIG, two GPR, two Adlican, two Peroxidasin-like proteins, three Trk neurotrophin receptors, a yet unnamed protein AAI11068, and three AMIGO. Some molecules (LINGO2, LINGO4, NGL1, SALM1, SALM5, and TrkB) were expressed exclusively in neuronal tissues, whereas others (ISLR1, GPR124, and Adlican2) exhibited non-neuronal expression profiles. However, the majority of LRRIG protein family exhibited broad mRNA tissue-expression profiles.
Collapse
Affiliation(s)
- Shunsaku Homma
- Department of Anatomy, School of Medicine, Fukushima Medical University, Fukushimashi, Fukushima 960-1295, Japan.
| | | | | | | |
Collapse
|