LOVELL, P.J.*; KOHN, A.B.; MOROZ, L.L.; Univ. of Florida, St. Augustine; Univ. of Florida, St. Augustine; Univ. of Florida, St. Augustine and Gainesville: Molluscan neurites grow into the genomic era: Insights from Aplysia transcriptome

In developing nervous systems, neurons are faced with the daunting task of finding appropriate synaptic targets located far from their own cell bodies. To accomplish this, neurons extend long neurites tipped with active growth cones to physically traverse the distance and respond to guidance molecules along the way. This neurite outgrowth can be modeled in cell culture where molluscan neurons regenerate robustly under controlled conditions. Specifically, we employed several classes of identified Aplysia neurons to model both induced neurite outgrowth and regeneration of isolated neurites following damage. We took advantage of the fact that neurite outgrowth of molluscan neurons can be easily induced or restricted simply by changing properties of the cell culture media. Specifically, neurons cultured in media supplemented with fresh haemolymph grow extensively while the same type of neurons do not grow in media supplemented with boiled haemolymph. Neurite outgrowth has been shown to be dependent on both transcription and translation of new proteins and a variety of distinct mRNA transcripts are known to be located extrasomatically, however, lack of broad scale molecular profiling tools have limited studies to individual transcripts of interest. In the current study, we have used broad scale EST collections from both whole neurons and isolated neurites as well as microarray analysis to investigate the genomic basis of neurite outgrowth from cultured identified Aplysia neurons at the transcriptome level.