DOI: 10.5061/dryad.wwpzgmswz
title: Sexually dimorphic and clock-gene specific effects of artificial light at night on Drosophila behavioral rhythms

description: Light pollution is a major anthropogenic environmental change and a
 significant threat to ecosystems. Among other detrimental effects on
 physiology, light at night (LAN) disrupts circadian rhythms in a wide
 range of species. However, the underlying neuronal and genetic mechanisms
 remain poorly understood. Here, we show that the loss of the circadian
 clock gene period (per) exacerbates the LAN-induced shift toward nocturnal
 behaviour, with a more pronounced effect on males. In contrast, the loss
 of cycle has no such effect on males or females; cyc null mutants are
 nocturnal under standard light‒dark cycles, and their activity and sleep
 profiles are minimally or not affected by LAN exposure. CRISPR-Cas9
 knockout of per in most clock neurons resembles the null mutant phenotype.
 Our results show that mutations in components of the positive and negative
 limbs of the circadian clock result in distinct responses to nocturnal
 light and highlight the role of genetic factors in modulating behavioural
 plasticity in response to environmental perturbations.
description: # Dataset README **Article Title**: *Sexually dimorphic and clock-gene
 specific effects of artificial light at night on *Drosophila* behavioral
 rhythms* (2025) Pranevicius A., Biondi G., Iyer A.R., Seiffe A., Depino
 A.M., and Fernandez M.P. **Journal**: *Proceedings of the Royal Society B*
 **Dataset DOI**:
 [10.5061/dryad.wwpzgmswz](https://doi.org/10.5061/dryad.wwpzgmswz)
 **Contact**: Maria de la Paz Fernandez
 ([fernanm@iu.edu](mailto:fernanm@iu.edu)) --- ## Description of the Data
 and File Structure * All data files are in `.csv` format. * Each file
 includes descriptors for sex, environmental condition (and genotype, when
 applicable). All experiments were conducted under a 12:12 light-dark cycle
 with either complete darkness at night (LD) or dim white light (ALAN).
 Zeitgeber time 0 (ZT12) indicates lights-on transition and Zeitgeber time
 12 (ZT12) indicates lights-off transition (under LD) or start of the dim
 light phase (ALAN). Circadian time 0 (CT0) indicates the start of the
 subjective day and Circadian Time 12 (CT12) the start of the subjective
 night, under constant temperature and darkness (DD). * **Empty cells** in
 the files that contain behavior data (all figures except Figure 2)
 indicate that either there was not a fly in the corresponding channel of
 the DAM activity monitor, or that it died before the end of the
 experiment. * **"n/a" entries** in immunohistochemistry data
 (Figure 2) indicates no datapoint (not the exact same number of brains was
 imaged for all timepoints and conditions). --- ## Figure 1 *
 **Fig1b_Dryad.csv : Night to day activity** This file contains locomotor
 activity data measured as beam crosses per minute in male and female
 *Drosophila*. Flies were either kept in standard light-dark (LD)
 conditions or exposed to artificial light at night (ALAN). The data is a
 ratio of diurnal (ZT0-12) over nocturnal (ZT12-24) activity, labeled in
 the figure as ‘nocturnality’. The genotype in Figure 1 data is w1118. *
 **Fig1c_Dryad.csv: Evening phase** Phase of evening activity (in hours)
 relative to lights-off (ZT12) for males and females under LD or ALAN. *
 **Fig1e_Dryad.csv : Total sleep** Total sleep duration (in minutes) for
 males and females under LD or ALAN. * **Fig1f_Dryad.csv : Day and night
 sleep** Day (ZT0-12) vs. night (ZT12-24) sleep durations for males and
 females under LD or ALAN. * **Fig1g_Dryad.csv : Morning and evening
 sleep** Sleep during ZT0–3 (morning) and ZT9–12 (evening) for males and
 females under LD or ALAN. --- ## Figure 2 * **Fig_2b_Dryad.csv** **: sLNv
 TIM timecourse** TIMELESS (TIM) nuclear staining in the small lateral
 ventral neurons (sLNvs) at the timepoints ZT2, 6, 10, 14, 18, and 22.
 Intensity in arbitrary units (a.u). * **Fig_2c_Dryad.csv** **: sLNv PER
 timecourse** PERIOD (PER) nuclear staining in the sLNvs at ZT10 and
 ZT22. Intensity in arbitrary units (a.u). * **Fig_2g_Dryad.csv** **: E3
 PER timecourse** PER staining in the E3 cluster of lateral neurons (LNds)
 for two antiphasic timepoints, ZT10 and ZT22. Intensity in arbitrary units
 (a.u). --- ## Figure 3 * **Fig_3a_Dryad.csv: Nocturnality in clock mutant
 males** This file contains locomotor activity data measured as beam
 crosses per minute in male *Drosophila* of three different genotypes (wild
 type CS, per01, and cyc01) under LD and ALAN conditions. Similar to Fig
 1b. * **Fig_3c_Dryad.csv: Nocturnality in clock mutant females** Same as
 3a but in females. * **Fig_3e_Dryad.csv: Sleep in clock mutant males**\
 Day and night sleep durations (minutes) in males of the same genotypes
 described in 3a. * **Fig_3f_Dryad.csv: Sleep in clock mutant females**
 Same as 3e but in females. --- ## Figure 4 * **Fig_4a_Dryad.csv:
 Nocturnality, per CRISPR knockout males** This file contains locomotor
 activity data measured as beam crosses per minute in male *Drosophila* for
 three genotypes: clk856-Gal4 and UAS-per-gs;UAS-Cas9 parental controls and
 experimental Clk856&gt;per-gs+Cas9 flies under LD or ALAN conditions.
 Similar to Fig 1b. * **Fig_4d_Dryad.csv: Nocturnality, per CRISPR knockout
 females** Same as 4a but in females. * **Fig_4c_Dryad.csv: Sleep, per
 CRISPR knockout males** Day and night sleep (in minutes) for same
 genotypes described in 4a for males and females under LD or ALAN. *
 **Fig_4f_Dryad.csv: Sleep, per CRISPR knockout females** Same as 4c but in
 females. --- ## Supplementary Figure 1 * **Fig_S1b_Dryad.csv : Morning
 phase** Morning activity phase (in hours) relative to the lights-on
 transition (ZT0) for males and females under LD or ALAN. *
 **Fig_S1c_Dryad.csv : Sleep bout length** Average bout duration (in
 minutes) for day and night sleep for males and females under LD or ALAN. *
 **Fig_S1d_Dryad.csv: Sleep latency** Time to the first sleep bout (in
 minutes) for males and females under LD or ALAN. --- ## Supplementary
 Figure 2 * **Fig_S2b_Dryad.csv: Subjective day sleep** Sleep (in minutes)
 for the first subjective day (Circadian Time, CT0-12) relative to the
 amount of sleep during the last day of either LD or ALAN (Zeitgeber Time,
 ZT0-12) for males and females. * **Fig_S2c_Dryad.csv: Total PER in sLNvs**
 PER (nuclear + cytoplasmic) intensity in the sLNvs at ZT10 and ZT22 for
 males and females under LD or ALAN. --- ## Supplementary Figure 3 *
 **Fig_S3c_Dryad.csv: Total sleep** Total sleep (in minutes) in CS, per01,
 and cyc01 males and females under LD or ALAN. --- ## Supplementary Figure
 4 * **Fig_S4a_Dryad.csv: Total sleep** Total sleep (in minutes) in
 clk856-Gal4, UAS-per-gs;UAS-Cas9, and Clk856&gt;per-gs+Cas9 males and
 females under LD or ALAN. **Genotype Key**: * **UAS control**:
 UAS-per-gs;UAS-Cas9 * **Gal4 control**: Clk856-Gal4 * **Experimental**:
 Clk856&gt;per-gs + Cas9