RT Journal Article
SR Electronic
T1 E93-depleted adult insects preserve the prothoracic gland and molt again
JF Development
JO Development
FD The Company of Biologists Limited
SP dev190066
DO 10.1242/dev.190066
VO 147
IS 22
A1 Kamsoi, Orathai
A1 Belles, Xavier
YR 2020
UL http://dev.biologists.org/content/147/22/dev190066.abstract
AB Insect metamorphosis originated around the middle Devonian, associated with the innovation of the final molt; this occurs after histolysis of the prothoracic gland (PG; which produces the molting hormone) in the first days of adulthood. We previously hypothesized that transcription factor E93 is crucial in the emergence of metamorphosis, because it triggers metamorphosis in extant insects. This work on the cockroach Blattella germanica reveals that E93 also plays a crucial role in the histolysis of PG, which fits the above hypothesis. Previous studies have shown that the transcription factor FTZ-F1 is essential for PG histolysis. We have found that FTZ-F1 depletion towards the end of the final nymphal instar downregulates the expression of E93, whereas E93-depleted nymphs molt to adults that retain a functional PG. Interestingly, these adults are able to molt again, which is exceptional in insects. The study of insects able to molt again in the adult stage may reveal clues about how nymphal epidermal cells definitively become adult cells, and whether it is possible to reverse this process.