title: Isoform-specific expression of the neuropeptide orcokinin in Drosophila melanogaster.
abstract: Orcokinins are neuropeptides that have been identified in diverse arthropods. In some species, an orcokinin gene encodes two isoforms of mature orcokinin peptide through alternative mRNA splicing. The existence of two orcokinin isoforms was predicted in Drosophila melanogaster as well, but the expression pattern of both isoforms has not been characterized. Here, we use in situ hybridization, antibody staining, and enhancer fusion GAL4 transgenic flies to examine the expression patterns of the A and B forms of orcokinin, and provide evidence that they are expressed differentially in the central nervous system (CNS) and the intestinal enteroendocrine system. The orcokinin A isoform is mainly expressed in the CNS of both larvae and adults. The A form is expressed in 5 pairs of neurons in abdominal neuromeres 1-5 of the larval CNS. In the adult brain, the A form is expressed in one pair of neurons in the posteriorlateral protocerebrum, and an additional four pairs of neurons located near the basement of the accessory medulla. Orcokinin A expression is also observed in two pairs of neurons in the ventral nerve cord (VNC). The orcokinin B form is mainly expressed in intestinal enteroendocrine cells in the larva and adult, with additional expression in one unpaired neuron in the adult abdominal ganglion. Together, our results provide elucidation of the existence and differential expression of the two orcokinin isoforms in the Drosophila brain and gut, setting the stage for future functional studies of orcokinins utilizing the genetically amenable fly model.
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Min Sung
authors.initials: MS
authors.lastname: Choi
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mizoguchi
authors.affiliation: Université de Bordeaux, INCIA UMR 5287 CNRS, 33405 Talence, France.
authors.forename: Jan A
authors.initials: JA
authors.lastname: Veenstra
authors.affiliation: Samsung Biomedical Research Institute, Department of Anatomy and Cell Biology, School of Medicine, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: KyeongJin
authors.initials: K
authors.lastname: Kang
authors.affiliation: School of Life Sciences, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea. Electronic address: kimyj@gist.ac.kr.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746, Republic of Korea. Electronic address: jykwon@skku.edu.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Kwon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000166:cytology / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D019858:Enteroendocrine Cells / Q000378:metabolism; D015870:Gene Expression; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D009479:Neuropeptides; D020033:Protein Isoforms; C079067:orcokinin
keywords: Drosophila melanogaster; Neuropeptide; Orcokinin