The Neuronal Transcriptome of Aplysia californica: A Platform for the Neurogenomics of Defined Neurons, Neuronal Compartments and Neuronal Circuitry
Leonid L. Moroz,1,2,8* John R. Edwards,3,8 Sathyanarayanan V Puthanveettil,4,8 Andrea Kohn,1,8 Thomas Ha,1,2 Andreas Heyland,1 Bjarne Knudsen,1 Anuj Sahni,1 Fahong Yu,1,5 Li Liu,1,5 Sami Jezzini,1,2 Ruslan Sadreyev,1 Peter Lovell,1 William Iannucculli,3 Minchen Chen,3 Tuan Nguyen,3 Huitao Sheng,3 Regina Shaw,1,5 Sergey Kalachikov,3 Yuri Panchin,1 William Farmerie,5 James J. Russo,3 Jingyue Ju,3,7* Eric R. Kandel4,6*
1The Whitney Laboratory for Marine Bioscience, University of Florida, 9505 Ocean Shore Blvd., St. Augustine, FL 32080
2Dept of Neuroscience and McKnight Brain Institute, 100 S. Newell Drive Bldg. 59, University of Florida, Gainesville, FL 32611
3Columbia Genome Center, College of Physicians and Surgeons, Columbia University, 1150 St. Nicholas Ave., New York, NY 10032
4Center for Neurobiology & Behavior and New York State Psychiatric Institute, Columbia University, 1051 Riverside Drive, Columbia University, New York, NY 10032
5Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, 32611
6Howard Hughes Medical Institute, 1051 Riverside Drive, Columbia University, New York, NY 10032
7Department of Chemical Engineering, Columbia University, 500 W. 120th St., New York, NY 10027
Abstract
The marine mollusc Aplysia is a well established experimental system for cellular and systems neural science because of the relatively simple organization of its nervous system and the presence within it of the largest nerve cells in the animal kingdom, many of which are uniquely identifiable in every member of the species. Until now, molecular analyses of Aplysia have been seriously handicapped by lack of adequate genomic information, with only 200 sequences publicly available when this project was initiated in 2003. By sequencing cDNA libraries from the central nervous system, we have identified over 175,000 ESTs (expressed sequence tags), of which 19,814 are unique neuronal gene products and 9,469 have been annotated. Through comparison with the complete genomic data available for Drosophila and C. elegans, we estimate that we have sequence information for approximately 50-70% of the total transcriptome of the Aplysia nervous system. We also identified 9,223 unique gene products in a modulatory serotonergic cell and about 1,000 unique gene products from its processes. Using gene expression oligoarrays constructed using the Aplysia EST database we also have characterized the transcript profile of sensory and motor neurons. In addition to increasing the amount of publicly available gene sequences of Aplysia by two orders of magnitude, this collection of transcripts is distinctive from a comparative biology point of view. It represents the largest database available for any member of the Lophotrochozoa clade of the animal kingdom. These molecular resources should allow the detailed study of the genomics of identified cells and circuits and provide in Aplysia a much needed bridge between genes, behavior, and learning.
