Patterns of Shaker family gene expression in single identified neurons of the American lobster, Homarus americanus

The patterns of expression of voltage gated potassium channel genes of the Shaker family have been mapped in identified neurons of the lobster (Homaru s americanus) ventral nerve cord using a single cell reverse transcriptase polymerase chain reaction procedure. Using specific oligonucleotides derive d from the sequences of the shakerm, shab, and shaw genes of the spiny lobs ter, Panulirus interruptus, we detected the corresponding potassium channel DNA fragments from Homarus americanus. The Homarus DNA fragments are 87-98 % identical at the nucleotide level to the Panulirus DNA fragments. We used the Panulirus primers to measure the complement of RNAs for shaker, shab, and shan: in single identified cells that use GABA, glutamate, octopamine o r serotonin as chemical messengers. Shaker and shaw RNAs were found in all four identified neuron types but shab RNA was not detected in serotonin cel ls under the present experimental conditions. All cells expressed alpha-tub ulin RNA, which serves as an internal control suggesting that cells are int act after dissection. In glial cells that surround the neuronal cell bodies , the potassium channel genes are expressed at low to non-detectable levels .