The adipokinetic hormones in the fall armyworm, Spodoptera frugiperda: cDNA cloning, quantitative real time RT-PCR analysis, and gene specific localization.
Small neuropeptides of the adipokinetic/red pigment-concentrating hormone (AKH/RPCH) family regulate energy metabolism in insects. Within lepidopterans, the nonapeptide Manduca sexta AKH (Manse-AKH) represents a widely occurring AKH, whereas the decapeptide Helze-HrTH (at first isolated from Helicoverpa zea) seems to be restricted to moths. Here we report the identification of the Manse-AKH-like Spofr-AKH 1 and the Helze-HrTH-like Spofr-AKH 2 prohormone precursors from the fall armyworm, Spodoptera frugiperda. Moreover, by PCR screening of a random primer cDNA library and by RACE, three 668, 835 and 1008 bp cDNA sequences were obtained, which encode putative translation products of 67-74 amino acids, each containing one copy of a peptide sequence that in its processed form has the sequence of QLTFSSGW-amide (Spofr-AKH 3). Another cDNA sequence of 634 bp encodes a putative translation product of 40 amino acids, potentially leading to one copy of an elongated, non-amidated Helze-HrTH (pQLTFSSGWGNCTS-OH; Spofr-AKH 4). Q-RT-PCR analysis showed that the Spofr-AKH mRNAs are expressed in 2d-old female brain/corpora cardiaca complexes, but also in ovaries, midgut, fat body, accessory glands and muscle tissues. Expression was also found in the ovaries of 4d-old females. Whole-mount in situ RT-PCR analysis with ovaries from 2d-old females showed that the Spofr-AKH 2 and Spofr-AKH 4 were mainly localized in the germarium (phase 3), whereas the Spofr-AKH 1, and the three mRNA isoforms of Spofr-AKH 3 were localized at the end of the vitellarium and in the fully developed oocytes (phase 1 and 2). The results suggest that Spofr-AKH genes play a role in the regulation of oocyte maturation in S. frugiperda.
Abdel-Latief
Mohatmed
M
Department of Applied Zoology/Animal Ecology; Institute of Biology; Free University Berlin, 12163 Berlin, Germany. mohatmed@zedat.fu-berlin.de
Hoffmann
Klaus H
KH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D005260:Female; D015723:Gene Library; D007301:Insect Hormones / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D010053:Ovary / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms / Q000032:analysis / Q000737:chemistry / Q000235:genetics; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D018411:Spodoptera / Q000235:genetics* / Q000378:metabolism