title: Demonstration of expression of a neuropeptide-encoding gene in crustacean hemocytes.
abstract: Crustacean hyperglycemic hormone (CHH) was originally identified in a neuroendocrine system-the X-organ/sinus gland complex. In this study, a cDNA (Prc-CHH) encoding CHH precursor was cloned from the hemocyte of the crayfish Procambarus clarkii. Analysis of tissues by a CHH-specific enzyme-linked immunosorbent assay (ELISA) confirmed the presence of CHH in hemocytes, the levels of which were much lower than those in the sinus gland, but 2 to 10 times higher than those in the thoracic and cerebral ganglia. Total hemocytes were separated by density gradient centrifugation into layers of hyaline cell (HC), semi-granular cell (SGC), and granular cell (GC). Analysis of extracts of each layer using ELISA revealed that CHH is present in GCs (202.8±86.7 fmol/mg protein) and SGCs (497.8±49.4 fmol/mg protein), but not in HCs. Finally, CHH stimulated the membrane-bound guanylyl cyclase (GC) activity of hemocytes in a dose-dependent manner. These data for the first time confirm that a crustacean neuropeptide-encoding gene is expressed in cells essential for immunity and its expression in hemocytes is cell type-specific. Effect of CHH on the membrane-bound GC activity of hemocyte suggests that hemocyte is a target site of CHH. Possible functions of the hemocyte-derived CHH are discussed.
authors.affiliation: Department of Biology, National Changhua University of Education, Changhua 50058, Taiwan.
authors.forename: Su-Hua
authors.initials: SH
authors.lastname: Wu
authors.forename: Yan-Jhou
authors.initials: YJ
authors.lastname: Chen
authors.forename: Shao-Yen
authors.initials: SY
authors.lastname: Huang
authors.forename: Wei-Shiun
authors.initials: WS
authors.lastname: Tsai
authors.forename: Hsin-Ju
authors.initials: HJ
authors.lastname: Wu
authors.forename: Tsan-Ting
authors.initials: TT
authors.lastname: Hsu
authors.forename: Chi-Ying
authors.initials: CY
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000235:genetics / Q000378:metabolism*; D003400:Astacoidea / Q000235:genetics / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D003001:Cloning, Molecular; D004789:Enzyme Activation; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006162:Guanylate Cyclase / Q000378:metabolism; D006434:Hemocytes / Q000378:metabolism*; D007447:Invertebrate Hormones / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*
chemical_list: D060829:Arthropod Proteins; D007447:Invertebrate Hormones; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D011498:Protein Precursors; C015947:hyperglycemic hormone, crustacean; C061766:hyperglycemic hormone precursor, crustacean; D006162:Guanylate Cyclase