Eclosion assay

The purpose of an eclosion assay is to count the number of flies that emerge over time from a developing population, which provides information on the circadian clock in the experimentally manipulated drosophila.

The first model of the bang box was developed at a Princeton University laboratory, mainly accredited to Colin Pittendrigh, to measure the time that adult drosophilids emerged from pupae populations in a controlled light and temperature environment.

For example, the bang box was used to measure eclosion activity in order to determine Clock mutants on the X chromosome of Drosophila that drastically change the period of the traditional 24-hour circadian rhythm.

[1] Some scientists have argued that this model, while more advanced than the former bang box construct, fails to account for changes in temperature and light exposure present in most flies’ natural environments.

[6] To address these issues, scientists at the University of Würzburg designed an open eclosion monitor where pupae and flies are exposed to abiotic factors in the environment.

The eclosion of the Indian meal moth Plodia interpunctella has been studied with tools similar to the bang box in order to examine the effects of temperature on circadian rhythms.

Nondiapausing larvae of the Indian meal moth have been used to study eclosion rhythms by counting the number of adults emerging from the food within a few minutes at one-hour intervals.

[8] In a 2012 study conducted by researchers at the University of Toyama, the number of emerging adults was pooled together in daily recordings in order to analyze the eclosion rhythms of the moths.

The number of insects that emerged at different time points was recorded when the larvae were exposed to various temperatures, and thus, this method was used to conclude that eclosion rhythms of the Indian meal moths are temperature-compensated.

Eclosion (the process during which insects emerge from their pupae) is regulated by circadian clocks. Thus, chronobiologists use different assays to measure eclosion timing and circadian rhythms in insects.
Simplified bang box schematic. Pupae (green) are held on a plate, and the container holding them is shaken at regular intervals to cause any eclosed flies (black) to fall into vials containing detergent. These vials are on a stage that also rotates at regular intervals (represented by the red arrow), which enables researchers to count the number of flies eclosed at each time interval.