title: In situ hybridization analysis of the expression of futsch, tau, and MESK2 homologues in the brain of the European honeybee (Apis mellifera L.).
abstract: BACKGROUND
  The importance of visual sense in Hymenopteran social behavior is suggested by the existence of a Hymenopteran insect-specific neural circuit related to visual processing and the fact that worker honeybee brain changes morphologically according to its foraging experience. To analyze molecular and neural bases that underlie the visual abilities of the honeybees, we used a cDNA microarray to search for gene(s) expressed in a neural cell-type preferential manner in a visual center of the honeybee brain, the optic lobes (OLs).
  
  
  RESULTS
  Expression analysis of candidate genes using in situ hybridization revealed two genes expressed in a neural cell-type preferential manner in the OLs. One is a homologue of Drosophila futsch, which encodes a microtubule-associated protein and is preferentially expressed in the monopolar cells in the lamina of the OLs. The gene for another microtubule-associated protein, tau, which functionally overlaps with futsch, was also preferentially expressed in the monopolar cells, strongly suggesting the functional importance of these two microtubule-associated proteins in monopolar cells. The other gene encoded a homologue of Misexpression Suppressor of Dominant-negative Kinase Suppressor of Ras 2 (MESK2), which might activate Ras/MAPK-signaling in Drosophila. MESK2 was expressed preferentially in a subclass of neurons located in the ventral region between the lamina and medulla neuropil in the OLs, suggesting that this subclass is a novel OL neuron type characterized by MESK2-expression. These three genes exhibited similar expression patterns in the worker, drone, and queen brains, suggesting that they function similarly irrespective of the honeybee sex or caste.
  
  
  CONCLUSIONS
  Here we identified genes that are expressed in a monopolar cell (Amfutsch and Amtau) or ventral medulla-preferential manner (AmMESK2) in insect OLs. These genes may aid in visualizing neurites of monopolar cells and ventral medulla cells, as well as in analyzing the function of these neurons.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Kumi
authors.initials: K
authors.lastname: Kaneko
authors.forename: Sayaka
authors.initials: S
authors.lastname: Hori
authors.forename: Mai M
authors.initials: MM
authors.lastname: Morimoto
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Nakaoka
authors.forename: Rajib Kumar
authors.initials: RK
authors.lastname: Paul
authors.forename: Tomoko
authors.initials: T
authors.lastname: Fujiyuki
authors.forename: Kenichi
authors.initials: K
authors.lastname: Shirai
authors.forename: Akiko
authors.initials: A
authors.lastname: Wakamoto
authors.forename: Satomi
authors.initials: S
authors.lastname: Tsuboko
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Takeo
authors.initials: T
authors.lastname: Kubo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001516:Bees / Q000235:genetics* / Q000254:growth & development; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect / Q000235:genetics*; D017403:In Situ Hybridization / Q000379:methods*; D019476:Insect Proteins / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011679:Pupa / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D019476:Insect Proteins