Inducible- and constitutive-type transcript variants of kakusei, a novel non-coding immediate early gene, in the honeybee brain

We previously identified a novel non-coding immediate early gene, termed kakusei, from the honeybee (Apis mellifera) and used it as a marker to detect neural activity in the brains of foraging workers ( Kiya et al., 2007 ). Here, we investigated the detailed kakusei gene structure. Expression analysis revealed that, in addition to the neural activity-inducible transcript variant, multiple neural activity-independent transcript variants were constitutively expressed from the same kakusei locus. In situ hybridization revealed that constitutive-type kakusei variants were detected in the whole brain and the RNA was localized predominantly in the neural nuclei, like the inducible-type variant, suggesting the concerted action of inducible- and constitutive-types of kakusei transcript variants on nuclear function.