• Made available online as an Accepted Preprint 10 January 2008
  • Accepted Preprint first posted online on 10 January 2008

Purification and characterization of an insulin-related peptide in the desert locust, Schistocerca gregaria: immunolocalization, cDNA cloning, transcript profiling and interaction with neuroparsin

  1. Jozef Vanden Broeck
  1. Department of Animal Physiology and Neurobiology, Zoological Institute K U Leuven, Naamsestraat 59, PO Box 02465, B-3000 Leuven, Belgium
  1. (Correspondence should be addressed to J Vanden Broeck Email: jozef.vandenbroeck{at}bio.kuleuven.be)


Members of the insulin superfamily are not restricted to vertebrates, but have also been identified in invertebrate species. In the current report, we present the characterization of Scg-insulin-related peptide (IRP), an insulin-related peptide in the desert locust, Schistocerca gregaria. This peptide was isolated from corpora cardiaca (CC) extracts by means of a high-performance liquid chromatography (HPLC)-based purification strategy. Subsequent cloning and sequencing of the corresponding cDNA revealed that the encoded Scg-IRP precursor displays the structural organization that is typical for members of the insulin superfamily. Moreover, immunocytochemistry on brain tissue sections demonstrated the presence of Scg-IRP in median neurosecretory cells of the pars intercerebralis and their projections towards the storage part of the CC. Quantitative real-time RT-PCR studies revealed the presence of Scg-IRP transcripts in a variety of tissues, including nervous tissue and fat body. Furthermore, these transcripts showed a tissue- and phase-dependent, temporal regulation during the reproductive cycle of adult males and females. Finally, we demonstrated that Scg-IRP interacts in vitro with a recombinant neuroparsin, a locust protein displaying sequence similarity with vertebrate IGF binding proteins.

  • Revision received 21 December 2007
  • Accepted 10 January 2008
| Table of Contents