Detection of MAO-A and MAO-B mRNAs in monkey brainstem by cross-hybridization with human oligonucleotide probes.
The distribution of mRNAs encoding the isoenzymes monoamine oxidase A and B (MAO-A and MAO-B) in monkey locus coeruleus and dorsal raphe nucleus was studied by in situ hybridization histochemistry using 35S-labelled oligodeoxynucleotide probes complementary to cloned human sequences. MAO-A mRNA was highly expressed in noradrenergic neurons of the locus coeruleus while MAO-B mRNA was abundantly and exclusively localized in serotoninergic neurons of the raphe. However, upon emulsion radioautography raphe neurons showed a level of MAO-A mRNA signal noticeably above the background. Our results indicate the utility of human MAO oligodeoxynucleotide probes to identify homologous species of transcripts in the brain of a non-human primate. They also suggest the coexistence of the isoenzymes in raphe neurons as well as the potential role of MAO-A in metabolizing serotonin in vivo.
Luque
J M
JM
Pharma Division, F. Hoffmann-La Roche Ltd, Basle, Switzerland. luque@ubaclu.unibas.ch
Bleuel
Z
Z
Hendrickson
A
A
Richards
J G
JG
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D006651:Histocytochemistry; D006801:Humans; D008251:Macaca; D008995:Monoamine Oxidase / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis*
D012333:RNA, Messenger; D008995:Monoamine Oxidase