Dim artificial light at night affects mating, reproductive output, and reactive oxygen species in Drosophila melanogaster

Abstract

Humans are lighting the night-time environment with ever increasing extent and intensity, resulting in a variety of negative ecological effects in individuals and populations. Effects of light at night on reproductive fitness traits are demonstrated across taxa however, the mechanisms underlying these effects are largely untested. One possible mechanism is that light at night may result in perturbed reactive oxygen species (ROS) and oxidative stress levels. Here, we reared Drosophila melanogaster under either dim (10 lx) light or no light (0 lx) at night for three generations and then compared mating and lifetime oviposition patterns. In a second experiment, we explored whether exposure to light at night treatments resulted in variation in ROS levels in the heads and ovaries of six, 23- and 36-day-old females. We demonstrate that dim light at night affects mating and reproductive output: 10 lx flies courted for longer prior to mating, and female oviposition patterns differed to 0 lx females. ROS levels were lower in the ovaries but not heads, of 10 lx compared with 0 lx females. We suggest that reduced ROS levels may reflect changes in ovarian physiology and cell signaling, which may be related to the differences observed in oviposition patterns. Taken together, our results indicate negative consequences for invertebrates under more stressful, urban, lit conditions and further investigation into the mechanisms driving these changes is warranted to manage invertebrate communities in a brighter future.

Artificial light at night as an environmental pollutant: An integrative approach across taxa, biological functions, and scientific disciplines

“…A major aim of our special issue was to reveal the multitude of molecular, physiological, and behavioral mechanisms that light pollution can affect. At the molecular and physiological level, these and previous papers have shown that ALAN can alter patterns of gene expression (Bedrosian, Galan, Vaughn, Weil, & Nelson, 2013;Dominoni et al, 2018;Fonken & Nelson, 2014;Shuboni & Yan, 2010), hormone secretion (Alaasam et al, 2018;de Jong et al, 2016;Dominoni, Goymann, Helm, & Partecke, 2013;Ouyang, Davies, & Dominoni, 2018), body temperature (Kumar et al, 2018), energy expenditure (Welbers et al, 2017), immune function (Bedrosian, Fonken, Walton, & Nelson, 2011;Cissé, Russart, & Nelson, 2017;Fonken, Lieberman, Weil, & Nelson, 2013), and oxidative stress (McLay et al, 2018;Navara & Nelson, 2007). Given, such extensive changes in the underlying physiology, it comes with no surprise that an impressive array of behavioral effects of ALAN have been shown.…”

“…From insects to mammals, several animal classes, both invertebrate and vertebrate, are represented. McLay, Nagarajan-Radha, Green, and Jones (2018) investigated effects of ALAN on reproduction and physiology in Drosophila. Insects were also the focus of Donners et al (2018), who modeled the attraction of several insect orders to light sources of different colors, allowing the application of light sources that reduce insect attraction.…”

“…Russart & Nelson (2018) in our special issue review the behavioral effects of ALAN. Some of these refer to changes in mating (Baker & Richardson, 2006; Botha, Jones, & Hopkins, 2017; Hau et al, 2017; McLay et al, 2018; van Geffen et al, 2015), singing (Da Silva & Kempenaers, 2017; Kempenaers et al, 2010), sleep (Sun, Raap, Pinxten, & Eens, 2017), mood and anxiety-related behaviors (LeGates et al, 2013), habitat selection (Yuen & Bonebrake, 2017), predation (Yuen & Bonebrake, 2017), migratory (Doren et al, 2017), and commuting movements (Spoelstra et al, 2017). Moreover, the special issue also includes a timely perspective from ulsebrook, Jones, Mulder, and Lesku (2018) on the impacts of ALAN on sleep.…”

The impact of artificial light at night on nocturnal insects: A review and synthesis

“…For example, the pink bollworm Pectinophora gossypiella can be artificially entrained by monochromatic yellow light emitted by low‐pressure sodium (LPS) lamps (Pittendrigh & Minis, ), and diurnal Bombus terrestris bumblebees by UV illumination (Chittka , Stelzer, & Stanewsky, ). Desynchronization reduces reproductive fitness of Drosophila melanogaster fruit flies (Xu, DiAngelo, Hughes, Hogenesch, & Sehgal, , see also McLay, Nagarajan‐Radha, Green, & Jones, ) and has the potential to disrupt vital biological processes in other taxa (Dominoni, Borniger, & Nelson, ; Gaston et al, ; Saunders, ).…”

Insect declines and agroecosystems: does light pollution matter?

“…Apart from acting as an ecological trap (Eisenbeis, ; Frank, ; Macgregor et al, ), light pollution harms insects by impeding communication, changing their physiology, life‐history traits and night habits, for example, migration, feeding and reproductive behaviour. ALAN was found to inhibit initiation of pupal diapause (van Geffen et al, ), reduce sex pheromone production (van Geffen et al, ), reduce mating (van Geffen et al, ) and interrupt feeding in moths (van Langevelde et al, ), reduce courtship behaviour and mating success in fireflies (Firebaugh & Haynes, ), decrease fecundity and adult survival, prolong courtship and alter oviposition patterns in Drosophila melanogaster (McLay et al, , ). By decreasing fitness, survival and reproduction, ALAN can increase mortality and decrease reproduction rates and population growth.…”