FY2018 Annual Report
Formation and Regulation of Neuronal Connectivity Research
Visiting Professor David Van Vactor
Abstract
The formation, refinement and maintenance of connectivity across complex neural circuits involves multiple levels of regulatory control over gene expression, from the production of mRNA to its processing, transport and translation. Our research program is focused on understanding post-transcriptional mechanisms essential for synaptic development and maintenance, and the networks of effector genes that mediate these key regulatory pathways. Using the genetic model organism Drosophila, we study transcriptome regulation within the motor system, with specific emphasis on the neuromuscular junction (NMJ) that has proven to be a powerful model for analysis of synapse function, development and disease. Our main project concerns the gene Survival of Motor Neurons (Smn), ortholog of the gene causal to Spinal Muscular Atrophy (SMA), currently thought to mediate synapse development, function and stability and protect motor neurons from degeneration and ultimate death. Through the combined application of transcriptome analysis and functional analysis in this genetic model, we are mapping the conserved mRNA targets of Smn relevant to synapse biology in order to identify key nodes and molecular pathways essential for synapse form and function.
1. Staff
- Dr. David Van Vactor, Professor
- Dr. Takakazu Yokokura, Group Leader (Project 1 & Drosophila Core)
- Dr. Cecilia Lu, Group Leader (Project 2)
- Seiko Yoshikawa, Technician (- Mar, 2019)
- Thi Thu Van Dinh, Technician
- Kun Xiao, Technician (- Dec, 2018)
- Yu-Pei Huang, Technician (- Mar, 2019)
- Rika Nakamura, Technician (Jan, 2019-)
- Chie Edwards, Research Unit Administrator
2. Collaborations
2.1 Theme: Computational analysis of RNA splicing patterns in high-content RNAseq datasets, and conservation of RNA splicing and stability effects from Drosophila to human models of Spinal Muscular Atrophy (SMA).
- Type of collaboration: Joint research
- Researchers/Team Member:
- Dr. Margarida Gama-Carvalho (University of Lisbon, Lisbon, Portugal)
- Professor David Van Vactor
- Dr. Takakazu Yokokura
- Seiko Yoshikawa
- Thi Thu Van Dinh
- Kun Xiao
2.2 Theme: Defining patterns of RNA splicing and stability characteristic of human IPS-derived mixed motor neuron model of Spinal Muscular Atrophy (SMA).
- Type of collaboration: Joint research
- Researchers:
- Dr. Lee Rubin (Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, USA)
- Professor David Van Vactor
- Dr. Takakazu Yokokura
- Seiko Yoshikawa
2.3 • Theme: MicroRNA Modulators of Amyotrophic Lateral Sclerosis (ALS) Models in Drosophila.
- Type of collaboration: Joint research
- Researchers:
- Dr. Spyros Artavanis-Tsakonas (Blavatnik Institute of Cell Biology, Harvard Medical School, Boston, MA, USA)
- Professor David Van Vactor
- Dr. Takakazu Yokokura
- Seiko Yoshikawa
- Kun Xiao
3. Activities and Findings
3.1 Spinal Muscular Atrophy (SMA)
Our analysis of Smn function in regulating the formation and maintenance of connectivity in the motor circuits of the Drosophila larva reveal that this conserved gene regulates multiple aspects of presynaptic and postsynaptic structure in a way that suggests modulation of multiple trans-synaptic signaling pathways, including the Bone-Morphogenetic Protein (BMP) factor Gbb (Glass-bottom boat) and its receptors Wit (Wishful thinking) and tkv (thinkc vien), as well as fibroblast growth factor.
Over the past year, we have completed the final phase of neuronal transcriptome sequencing for the Drosophila model of SMA after optimization of the sequencing pipeline in collaboration with the OIST sequencing center. Our final RNAseq datasets are being analyzed for differential expression and exon usage in preparation for functional validation experiments in the fly model, and for comparisons to the human iPS-derived samples that are currently being sequenced. Our analysis of these data sets, through close collaboration with the labs of Drs. Gama-Carvahlo (Biosys, Lisbon) and Wall (Stanford University), will also help us determine the degree of conservation for mRNA splcing patterns across species for CNS-enriched isoforms of the genes conserved between Drosophila and human. We find hundred of genes altered in steady state level so far, and expect even higher numbers to display alterations in exon usage patterns. Current production of isoform-specific antibodies will be used to confirm the candidate Smn effectors in several key pathways, as a prelude to isoform-specific transgenic rescue experiments.
4. Publications
4.1 Journals
Nothing to report
4.2 Books and other one-time publications
Lu, C.S. and Van Vactor, D. (2019) Genetic Analysis of Synaptogenesis in Cellular Migration and Formation of Neuronal Connections: Comprehensive Developmental Neuroscience, Volume 2. Elsevier Ltd., London, UK.
4.3 Oral and Poster Presentations
- Yokokura, T., Yoshikawa, S., Chobanyan, T., Goto, H., AF dos Santos, H., Fonseca, A., Lynes, M., Chang, H., Dimlich, D., Kankel, M., Sen, A., Artavanis-Tsakonas, S., Rubin, L., Gama Carvalho, M, Van Vactor, D. mRNAs Altered in Human and Drosophila Models of Spinal Muscular Atrophy. Workshop on Integrative Approaches in Neurodegeneration; Lisbon, Portugal. June 21-23, 2018
- Yokokura, T., McNeill, E.M., Chobanyan, T., Yoshikawa, S., Goto, H., AF dos Santos, H., Fonseca, A., Lynes, M., Rubin, L., Gama Carvalho, M, Van Vactor, D. Mutants Lacking Drosophila Smn Display SMA Disease-relevant Neuromuscular Defects that can be Rescued by Elevation in Conserved Transynaptic Signaling Pathway. Workshop on Integrative Approaches in Neurodegeneration; Lisbon, Portugal. June 21-23, 2018
- Yokokura, T., AF dos Santos, H., Yoshikawa, S., Fonseca, A., Lynes, M., Rubin, L. L., Gama Carvalho, M., Van Vactor, D. Defining Conserved Gene Networks on SMN function using Drosophila SMA model and human iPS driven neural cells. 22nd International SMA Researcher Conference; Dallas TX, USA. June 14-16, 2018
- Van Vactor, D., AF dos Santos, H., Yoshikawa, S., Fonseca, A., Lynes, M., Rubin, L. L., Gama Carvalho, Yokokura, T. (2018): JPND Workshop on “Integrative Approaches in Neurodegeneration”, U. Lisboa, Lisbon, Portugal.
- Van Vactor, D., AF dos Santos, H., Yoshikawa, S., Fonseca, A., Lynes, M., Rubin, L. L., Gama Carvalho, Yokokura, T. (2019): ”Modeling Degenerative Disease in the Drosophila Motor System” HU MARC U-START Program, Hampton University, Hampton, VA.
- Van Vactor, D., AF dos Santos, H., Yoshikawa, S., Fonseca, A., Lynes, M., Rubin, L. L., Gama Carvalho, Yokokura, T. (2019) ”Modeling Degenerative Disease in the Drosophila Motor System” [Keynote lecture] Annual Symposium, Developmental Biology Training Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA.
- Van Vactor, D., AF dos Santos, H., Yoshikawa, S., Fonseca, A., Lynes, M., Rubin, L. L., Gama Carvalho, Yokokura, T. (2019): ”Modeling Spinal Muscular Atrophy in the Drosophila Motor System” HMS Initiative for RNA Medicine Seminar Series, Beth Israel Deaconess Medical Center Cancer Center, Boston, MA.
5. Intellectual Property Rights and Other Specific Achievements
Nothing to report
6. Meetings and Events
6.1 Developmental Neurobiology Course 2018
- Date: July 31 – August 12, 2018
- Venue: OIST Campus
- Co-organizers:
- Prof. Yoko Yazaki-Sugiyama(OIST)
- Prof. Ichiro Masai(OIST)
- Dr. Hiroshi Kawasaki(Tohoku Univ.)
- Dr. Hiroshi Kohsaka(Tokyo Univ.)
- Prof. David Van Vactor(OIST)
- Keynote Speakers:
- Dr. Erwin Neher (Max Planck Institute for Biophysical Chemistry, Göttingen)
- Dr. Christiane Nüsslein-Volhard (Max Planck Institute for Developmental Biology, Tübingen)
- Lecturers:
- Dr. Thomas R. Clandinin (Stanford University)
- Dr. Yasunori Hayashi (Kyoto University)
- Dr. Takao Hensch (Harvard University)
- Dr. Suresh Jesuthasan (Institute of Molecular and Cell Biology)
- Dr. Mineko Kengaku (Kyoto University)
- Dr. Stephan Liberles (Harvard Medical School)
- Dr. Hitoshi Okamoto (RIKEN Brain Science Institute)
- Dr. Noriko Osumi (Tohoku University)
- Dr. Iris Salecker (The Francis Crick Institute)
- Dr. Felix E. Schweizer (University of California, Los Angeles)
- Dr. Nirao Shah (Stanford University)
- Dr. Tomoyuki Takahashi (OIST)
- Dr. Ryohei Yasuda (Max Planck Florida Institute)
- Dr. Yoshihiro Yoshihara (RIKEN Brain Science Institute)
- Dr. Stephanie A. White (University of California, Los Angeles)
- Dr. Yimin Zou (University of California, San Diego)
6.2 Collaborative International Undergraduate Workshop 2018
- Title: Quantitative Analysis of Behavior & Neurobiology
- Date: August 17th - 23rd, 2018
- Venue: OIST Campus
- Co-organizers:
- Prof. David Van Vactor(OIST)
- Prof. Mahesh Bandi(OIST)
- Dr. Thomas Clandinin(Stanford University)
- Lecturer Team:
- Dr. Tom Clandinin (Stanford University)
- Dr. Jason Heustis (Harvard Medical School)
- Dr. Shreyas Mandre (Brown University)
- Dr. Elizabeth McNeill (College of human Genetics, Iowa State University)
- Dr. Marion Silies (Universitat Goettengen)
- Dr. Madhu Venkadesan (Yale University
- Dr. Mason Klein (University of Miami)
7. Other
Nothing to report.