FY2014 Annual Report

Formation and Regulation of Neuronal Connectivity Unit

Visiting Professor David Van Vactor


We aim to explore the mechanisms that underlie the formation and maintenance of synaptic connections in order to better understand the regulatory strategies and molecular machinery required to build the metazoan nervous system.  Our unit is currently focused on post-transcriptional mechanisms upstream of signaling pathways that shape development of the Drosophila neuromuscular junction (NMJ), a premier model for genetic analysis of synapse form and function.  Through analysis of a Drosophila model for the human neurodegenerative disease Spinal Muscular Atrophy (SMA), we have collaborated with multiple laboratories to map the underlying genetic network and determine how loss of the underlying gene SMN (Survival of Motor Neurons) alters NMJ development.  By comparing the genes dependent on SMN via transcriptome level sequencing with those genes and pathways that modulate SMN in vivo phenotypes, we are identifying candidates that may explain the impact of SMN loss on NMJ function. In addition, we have begun to examine other RNA-mediated regulatory mechanisms, such as microRNAs, in an effort to understand the various strategies used to tune synaptic gene networks to create robust connectivity during development.

1. Staff

  • Dr. David Van Vactor, Professor
  • Dr. Takakazu Yokokura, Group Leader
  • Ms. Seiko Yoshikawa, Technician
  • Dr. Cecilia Lu, Research Scientist (STG)
  • Dr. Deena Vardhini Yeraguntla, Technician (May 2014 - )
  • Ms. Shino Fibbs, Research Administrator

2. Collaborations

  • 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: Dr. Margarida Gama-Carvalho (University of Lisbon, Lisbon, Portugal)
  • 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 (Dept. of Stem Cell and Regenerative Biology, Harvard University, Boston, MA, USA)
  • Theme: MicroRNA Modulators of Spinal Muscular Atrophy (SMA) Models in Drosophila and C. elegans.
    • Type of collaboration: Joint research
    • Researchers: Dr. Anne Hart (Dept. of Biology, Brown University, Providence, RI, USA)

3. Activities and Findings

3.1 Spinal Muscular Atrophy (SMA)

Over the past year, our transcriptome analysis of Drosophila and human iPS-derived models for SMA has identified a large number of SMN-dependent mRNA species.  After refining methods of sequence data analysis and quality control with our colalborators (Amaral et al., 2014), we have begun the last phase of our analysis to identify RNA splicing changes induced by reduction in SMN function.  Using conservation and functional validation in the model systems as key guides, we are currently working to define the optimal pathways for investigation.  Our data suggest that several conserved intracellular proteins required for transynaptic signaling between motor neurons and muscles are dependent on SMN activity.

3.2 Micro RNA Regulation of Synaptic Adhesion Molecules

Over the past year, after completing our analysis of microRNA-8 regulation of the immunoglobulin cell adhesion molecules (IgCAMs) Neuroglian/L1 and Fasciclin III (Lu et al., 2014), we have extended our analysis to define the intermediary that links miR-8 to the conserved Nrg/L1 gene.  This line of inquiry suggests that post-transcriptional regulation of a conserved DNA-binding factor responsible for transcriptional repression may be the key functional link.  To better understand the proteins and RNAs differentially regulated and/or associated with key synaptic IgCAMs, we have also extended our proteomic analysis of the embryonic nervous system.

4. Publications

4.1 Journals

  1. Amaral AJ.,  Brito FF., Chobanyan T., Yoshikawa S., Yokokura T., Van Vactor D., Gama-Carvalho M. Quality assessment and control of tissue specific RNA-seq libraries of Drosophila transgenic RNAi models. Front Genet. 5:43. doi: 10.3389/fgene.2014.00043. eCollection (2014)
  2. Lu CS., Zhai B., Mauss A., Landgraf M., Gygi S., Van Vactor D., Micro RNA-8 promotes robust motor axon targeting by coodinate regulation of cell adhension molecules during synapse development. Philos Trans R Soc Lond B Biol Sci. 369(1652). pii: 20130517. doi: 10.1098/rstb.2013.0517. (2014)

4.2 Books and other one-time publications

Nothing to report

4.3 Oral and Poster Presentations

  1. Van Vactor, D., A Brief History of Developmental Biology, Developmental Neurobiology Course, Okinawa, Japan, June 30, 2014
  2. Van Vactor, D., Invertebrate Embryology and Genetics, Developmental Neurobiology Course, Okinawa, Japan, June 30, 2014
  3. Van Vactor, D., Axon Guidance, Targeting and the Neuronal Cytoskeleton, Developmental Neurobiology Course, Okinawa, Japan, July 3, 2014
  4. Yokokura, T., Identify genes affected by reduction of SMN levels with trasnscriptome analysis, 26th Takato Molecular-Cellular Biology Symposiu, Takato, Nagano, Japan, August 28, 2014
  5. Yoshikawa, S., Expression analysis of splice variants in Drosophila models of Spinal Muscular Atrophy, Takato Molecular-Cellular Biology Symposium., Takato, Nagano, Japan, August 28, 2014
  6. Yokokura T., Transriptome analysis to identify genes affected by reduction of SMN levels., 37th Annual Meeting of Molecular Biology Society of Japan., Yokohama, Kanagawa, Japan, November 27, 2014
  7. Yokokura T., Elucidating the mechanism to regulate gene expression by Survival Motor Neuron Gene., 56th Annual Drosophila Research Conference., Chicato, IL, USA. March 4-8, 2015
  8. Yokokura, T. Transciptome analysis to identify genes affected in SMA. Informal seminar, Department of Medical Chemistry Graduate School of Medicine, Kyoto University, Kyoto, Japan. March 21, 2015

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report

6. Meetings and Events

6.1 Nikon-OIST-Harvard Imaging Symposium

  • Date: May 2, 2014
  • Venue: Harvard Medical School
  • Organizers: Drs. David Van Vactor and Jennifer Waters
  • Speakers:
    • Tom Kirchhausen (HMS/Cell Biology)
    • Xiaowei Zhuang (Harvard University)
    • Samara Reck-Peterson (HMS/Cell Biology)
    • Joe Loparo (HMS/BCMP)
    • Mahesh Bandi (OIST)
    • Jagesh Shah (HMS/Systems Biology)
    • Bernd Kuhn (OIST)
    • Bernardo Sabatini  (HMS/Neurobiology)
    • Tadashi Yamamoto (OIST)
    • Tomoyuki Takahashi (OIST)
    • David Rudner (HMS/Cell Biology)
    • Ichiro Masai (OIST)

6.2 OIST Visit to MBL: Advanced Quantitative Light Microscopy Course (AQLM)

  • Date: May 3, 2014
  • Venue: Marine Biological Laboratory, Woods Hole, MA
  • Organizers: Drs. David VAn Vactor and Takakazu Yokokura
  • Hosts: Drs. Justin Teraska, Kip Sluder, and Aaron Straight

6.3 Developmental Neurobiology Course 2014

  • Date: June 30 - July 15, 2014
  • Venue: OIST Campus
  • Co-organizers: Drs. David Van Vactor, Gordon Arbuthnott, Ichiro Masai, and Yoko Yazaki-Sugiyama
  • Speakers:
    • Dr. David Van Vactor (Harvard Medical School/OIST)
    • Dr. Ichiro Masai (OIST)
    • Dr. Jon Clarke (King's College London)
    • Dr. Tatsushi Igaki (Kyoto University)
    • Dr. Takao Hensch (Harvard University)
    • Dr. Gordon Arbuthnott (OIST)
    • Dr. Mineko Kengaku (Kyoto University)
    • Dr. Anne Hart (Brown University)
    • Dr. Keshv Dani (OIST)
    • Dr. Yoko Yazaki-Sugiyama (OIST)
    • Dr. Yishi Jin (UC San Diego)
    • Dr. Andrew Chisholm (UC San Diego)
    • Dr. Ronald Davis (Scripps Research Institute Florida)
    • Dr. Gian Turrigiano (Brandeis University)
    • Dr. Sacha Nelson (Brandeis University)
    • Dr. Masashi Yanagisawa (University of Tsukuba)
    • Dr. Yoshihiro Yoshihara (RIKEN BSI)
    • Dr. Atsushi Miyawaki (RIKEN BSI)
    • Dr. Aravinthan Samuel (Harvard University)
    • Dr. Hiroshi Kohsaka (the University of Tokyo)
    • Dr. Hiroshi Kawasaki (Kanazawa University)
    • Dr. Thomas Reh (University of Washington)
    • Dr. Yasunori Hayashi (RIKEN BSI)
    • Dr. Lee Rubin (Harvard Medical School)

6.4 OIST Summer Courses and Workshop Alumni Reunion & OIST Graduate University Social at Society for Neuroscience

  • Date: November 16, 2014
  • Venue: Washington DC (at Society for Neuroscience Meeting)
  • Poster


7. Other

Nothing to report.