bursicon

Bursicon is a heterodimer glycoprotein hormone that is involved in the regulation of ecdysis and postecdysis processes associated with expansion, tanning, and sclerotization of the cuticle as well as feeding behavior in insects and innate immunity in crustaceans.

burs, Mr 15,678; pburs, Mr 13,059.

In D. melanogaster, bursicon controls cuticle sclerotization and melanization.In D. melanogaster, B. mori, and the beetle Tribolium castaneum, it is necessary for the expansion and hardening of the wings.The expansion of wings requires bursicon-induced extensibility of the wing cuticle, as demonstrated in the moth M. sexta.In D. melanogaster, burs-β is an important signal for controlling ecdysis behavior.In the crab C. sapidus, bursicon controls the deposition and thickening of the new cuticle as well as the granulation of hemocytes.In both Procambarus clarkii and D. melanogaster, bursicon homodimers induce innate immunity by altering antimicrobial peptides via Relish.Besides, burs-α in D. melanogaster binds to its neuronal receptor DLgr2, eventually regulating organismal resistance to metabolic challenges through Adipokinetic hormone signaling.

In the larvae of D. melanogaster, bursicon appears to be released in two temporal waves, the first prior to the onset of ecdysis and the second immediately after ecdysis onset. In adults, bursicon is also released in two consecutive waves. Initial bursicon secretion from two neurons in the SG subsequently elicits its secondary release from a cluster of abdominal neurons, which controls the expansion, hardening, and pigmentation of the cuticle and wings.In Neocaridina heteropoda, the abdominal ganglion is the main neurohemal release site of bursicon.