Light and peptidergic eclosion hormone neurons stimulate a rapid eclosion response that masks circadian emergence in Drosophila.
Light signals can entrain circadian clocks, but they can also mask aspects of the circadian output. We have analyzed the masking effects of a lights-on (LOn) signal on Drosophila eclosion. The LOn response results in 12-21% of the flies that emerge on a given day eclosing within 10 min of the LOn signal. Flies that lack the neuropeptide eclosion hormone (EH), or in which its release is inhibited by the tetanus toxin light chain, lack the response. Optic photoreceptors in both the ocelli and the compound eyes appear to be required for the response. The LOn signal has two effects: (1) it drastically reduces the interval between EH release and eclosion, presumably by suppressing a transient descending inhibition that immediately follows EH release, and (2) it stimulates premature EH release. The LOn signal does not influence the latency of wing spreading, an EH-regulated post-ecdysis behavior.
McNabb
Susan L
SL
Department of Zoology, Box 351800, University of Washington, Seattle, WA 98195-1800, USA. smcnabb@u.washington.edu
Truman
James W
JW
D000818:Animals; D002940:Circadian Rhythm; D054910:Compound Eye, Arthropod / Q000166:cytology / Q000378:metabolism; D004330:Drosophila / Q000254:growth & development / Q000502:physiology / Q000528:radiation effects*; D005260:Female; D007301:Insect Hormones / Q000235:genetics / Q000378:metabolism*; D008018:Life Cycle Stages; D008027:Light; D008297:Male; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism; D015398:Signal Transduction / Q000528:radiation effects; D013744:Tetanus Toxin / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D019076:Transgenes; D014921:Wings, Animal / Q000254:growth & development
D007301:Insect Hormones; D013744:Tetanus Toxin; C042645:eclosion hormone