Expression of two microRNAs, ame-mir-276 and -1000, in the adult honeybee (Apis mellifera) brain

To identify candidate microRNAs involved in post-transcriptional regulation of brain (region)- selective gene expression in the adult honeybee brain, we isolated eight microRNAs: seven known microRNAs, ame-mir-2-1, -8, 13a, -34, -276, -317, -1000, and one novel one, named mir-hbd, that has significant sequence similarity with the Drosophila dme-mir-11. Among them, ame-mir-1000 and -276 were expressed in a brain-selective and -preferential manner, respectively, in workers and drones. In particular, ame-mir-276-expression was enriched in the optic lobes and in the small type-Kenyon cells of the mushroom bodies in the nurse bee, forager, queen, and drone brains. Almost all predicted targets of amemir- 1000 and -276 encode neural function related genes, suggesting the involvement in neural function of both microRNAs.