Crustacean Hyperglycemic Hormone Family: Old Paradigms and New Perspectives

SYNOPSIS. I present an overview of recent research on the isolation and characterization of members of the crustacean hyperglycemic hormone (CHH) neuropeptide family. Members of this arthropod-specific family include CHH, molt-inhibiting hormone (MIH), vitellogenesis-inhibiting hormone (VIH), and mandibular organ-inhibiting hormone (MOIH). There are two subfamilies of this neuropeptide group, based upon the presence or absence of a C-terminal CHH precursor-related peptide. There are also sequence motif differences between these subfamilies. Most of the peptides comprising this neuropeptide family are synthesized and released by the eyestalk X-organ/sinus gland complex. Recent experiments have demonstrated the presence of extra-eyestalk cells that produce CHH and the assignment of additional functions to this hormone family.