Endocrine cascades during ecdysis in decapod crustaceans

Crab moulting

For insects, much is known concerning the precisely coordinated series of endocrine cascades culminating in successful ecdysis. Progress in this area has been rapid in view of the availability of genomic information for Drosophila, and of course, the extensive mutant background of this model. For crustaceans, much less is known. Nevertheless, we are beginning to dissect the neurohormonal pathways associated with ecdysis in crabs. Notwithstanding the very different ways in which both groups of arthropods control synthesis of ecdysteroids (moulting hormones)- in insects ecdysteroidogenesis is stimulated by prothoracicotropic hormone (PTTH), Xrayyet in crustaceans, this process is inhibited by moult-inhibiting hormone (MIH), there seem to be some endocrine cascades which occur during ecdysis (e.g. crustacean cardioactive peptide and bursicon (Wilcockson and Webster, 2008; Webster et al, 2013), which are common to both groups of arthropods, yet there are some that are unique to crustaceans, for example the release of crustacean hyperglycaemic hormone from gut endocrine cells prior to ecdysis, which result in water uptake, thus leading to post-ecdysial swelling. Whilst decapod crustaceans are still relatively genetically intractable, they offer some advantages, not least in terms of their size, which allows real-time monitoring of hormone titres. Our hypothesis-driven work is now benefiting also from next generation sequencing technologies to reveal previously unobtainable transcriptome data.

Funded by BBSRC.
Researchers: Dr S.G. Webster, Dr D.C. Wilcockson, Dr J.S. Chung