title: Specific Expression of Aplysia Phosphodiesterase 4 in Bag Cells Revealed by in situ Hybridization Analysis.
abstract: Phosphodiesterases (PDEs) play a key role in the regulation of cyclic adenosine monophosphate (cAMP), which in turn mediates various cellular functions including learning and memory. We previously cloned and characterized three PDE4 isoforms (ApPDE4) from Aplysia kurodai. Using reverse transcription polymerase chain reaction (RT-PCR), we found that ApPDE4 isoforms are primarily expressed in the central nervous system. However, the detailed distribution of ApPDE4 mRNA in Aplysia individual ganglions was not evident. In this study, to determine the distribution of ApPDE4 mRNAs in Aplysia ganglions, we performed in situ hybridization (ISH) using a probe targeting ApPDE4, including the PDE catalytic domain. Interestingly, we found the strongest ISH-positive signals in the symmetrical bag cell clusters of the abdominal ganglion. The R2, R14, L7, L2 and L11 neurons in the abdominal ganglion, LP1 neuron in pleural ganglion, and metacerebral (MCC) neurons were ISH-positive. Mechanosensory neurons of the sensory cluster were also stained on the ventral aspect of the right and left pleural ganglia. Taken together, we found the detailed distribution of ApPDE4 mRNA in Aplysia ganglion and support their roles in serotonin (5-HT)-induced synaptic facilitation of Aplysia mechanosensory neurons.
authors.affiliation: Department of Ecological Science, College of Ecology and Environment, Kyungpook National University, Sangju 37224, Korea.
authors.forename: Deok-Jin
authors.initials: DJ
authors.lastname: Jang
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea.
authors.forename: Hyoung F
authors.initials: HF
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Sim
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea.
authors.forename: Chae-Seok
authors.initials: CS
authors.lastname: Lim
authors.affiliation: Department of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea.
authors.forename: Bong-Kiun
authors.initials: BK
authors.lastname: Kaang
keywords: Aplysia; bag cell; in situ hybridization; phosphodiesterase 4