Light and temperature measurements and untargeted proteomic measurements

The right timing of animal physiology and behavior ensures the stability
of populations and ecosystems. In order to predict anthropogenic impacts
on these timings, more insight is needed into the interplay between
environment and molecular timing mechanisms. This is particularly true in
marine environments. Using high-resolution, long-term daylight
measurements from a habitat of the marine annelid Platynereis dumerilii,
we find that temporal changes in UVA/deep violet intensities, more than
longer wavelengths, can provide annual time information, which differs
from annual changes in photoperiod. We developed experimental setups that
resemble natural daylight illumination conditions, and automated,
quantifiable behavioral tracking. Experimental reduction of UVA/deep
violet light (app. 370-430nm) under long photoperiod (LD16:8)
significantly decreases locomotor activities, comparable to the decrease
caused by short photoperiod (8:16). In contrast, altering UVA/deep violet
light intensities does not cause differences in locomotor levels under
short photoperiod. This modulation of locomotion by UVA/deep violet light
under long photoperiod requires c-opsin1, an UVA/deep violet-sensor
employing Gi-signalling. C-opsin1 also regulates the levels of
rate-limiting enzymes for monogenic amine synthesis and of several
neurohormones, including PDF, Vasotocin (Vasopressin/Oxytocin) and NPY-1.
Our analyses indicate a complex inteplay between UVA intensities and
photoperiod as indicators of annual time.