Final heterodimeric neurohormone released at the end of the molting cycle, involved in the sclerotization (tanning) of the insect cuticle, melanization and wing spreading. Heterodimer of burs and pburs. The bursicon gene is encoded by two loci: burs124 contains exons 1, 2 and 4, and burs3 contains exon 3. Exon 3 is trans-spliced into position in the mature transcript. This unusual gene arrangement has existed for at least the 150 million years (MY) of mosquito evolution since the split of the culicid and anophelid family lineages, but is younger than the 250 MY split of the dipteran suborders Nematocera and Brachycera (containing the Culicidea and Drosophilidae, respectively).