'Foraging' for a place to lay eggs: A genetic link between foraging behaviour and oviposition preferences

Abstract

Gravid female arthropods in search of egg-laying substrates embark on foraging-like forays: they survey the environment assessing multiple patches, tasting each with their tarsi and proboscis, and then, if interested, they deposit an egg (or eggs). In fruit flies, Drosophila melanogaster, allelic variation in the foraging gene (for) underlies the rover/sitter foraging behaviour polymorphism. Rover flies (forR) are more active foragers (both within and between food patches) compared to sitters (fors). In nematodes, Caenorhabditis elegans, a mutation in egl-4, the ortholog of for, leads to aberrations in egg laying. Given this and the notion that females may ‘forage’ for a place to oviposit, we hypothesized that for may underlie egg-laying decisions in the fruit fly. Indeed, when given a choice between patches of low- and high-nutrient availability, rovers lay significantly more eggs on the low-nutrient patches than sitters and also a sitter mutant (fors2). We confirm the role of for by inducing rover-like oviposition preferences in a sitter fly using the transgenic overexpression of for-mRNA in the nervous system.

C. elegans episodic swimming is driven by multifractal kinetics

“…The colonies of bacteria that C. elegans worms feed on grow in a fractal shape 48 . In C. elegans , the actively-moving state is likely to enable food foraging, whereas the inactive state is likely associated with food intake, egg-laying, or resting to save energy or satiety 23 , 28 – 30 , 49 , 50 . Temporal correlation in the inactive state gives rise to a series of long and short periods for food intake that may follow the fractally-shaped bacterial colony 48 , whereas temporal correlation in active state residence-time series gives rise to a series of long- and short-distance foraging bouts that may follow the interbranch distances of a fractally-shaped bacterial colony.…”

“…Individual Drosophila flies 8 and Leptothorax allardycei worker ants 27 also alternate between an actively-moving state and a resting state in an episodic manner. Thus, episodic behavior is a conserved presentation in invertebrates that is thought to be adaptive for supporting food exploration, energy conservation, and reproductive success 8,22,23,28 .…”

Habitat connectivity is determined by the scale of habitat loss and dispersal strategy

“…Both scenarios could have detrimental effects if genetic variation underlying dispersal and migratory behaviors also act pleiotropically on functionally different traits. For example, for has pleiotropic effects on numerous traits, including larval foraging behavior (Sokolowski, 2001), aggression in adult males (Wang & Sokolowski, 2017), and oviposition site selection in females (McConnell & Fitzpatrick, 2017) (for extensive review and phenotypes, see Reaume & Sokolowski, 2009 (Berthold, 1999), and in fact most birds have this genetic 'machinery'.…”

C. elegansepisodic swimming is driven by multifractal kinetics

“…The colonies of bacteria that C. elegans worms feed on grow in a fractal shape 45 . In C. elegans , the actively-moving state is likely to enable food foraging, whereas the inactive state is likely associated with food intake, egg-laying, or resting to save energy or satiety 24,29–31,46,47 . Temporal correlation in the inactive state gives rise to a series of long and short periods for food intake that may follow the fractally-shaped bacterial colony, whereas temporal correlation in active state round series gives rise to a series of long- and short-distance foraging bouts that may follow the interbranch distances of a fractally-shaped bacterial colony.…”

“…On a solid agar plate, C. elegans also move in an episodic manner, wherein they crawl actively and persistently in one direction or crawl slowly and stay within a small area, behavioral states called roaming and dwelling/quiescence, respectively 24,26,27 Individual Drosophila flies 9 and Leptothorax allardycei worker ants 28 also alternate between an actively-moving state and a resting state in an episodic manner. Thus, episodic behavior is a conserved presentation in invertebrates that is thought to be adaptive for supporting food exploration, energy conservation, and reproductive success 9,23,24,29 .…”