An integrated hybrid microfluidic device for oviposition-based chemical screening of adult Drosophila melanogaster

Abstract

Chemical screening using Drosophila melanogaster (the fruit fly) is vital in drug discovery, agricultural, and toxicological applications. Oviposition (egg laying) on chemically-doped agar plates is an important read-out metric used to quantitatively assess the biological fitness and behavioral responses of Drosophila. Current oviposition-based chemical screening studies are inaccurate, labor-intensive, time-consuming, and inflexible due to the manual chemical doping of agar. In this paper, we have developed a novel hybrid agar-polydimethylsiloxane (PDMS) microfluidic device for single- and multi-concentration chemical dosing and on-chip oviposition screening of free-flying adult stage Drosophila. To achieve this, we have devised a novel technique to integrate agar with PDMS channels using ice as a sacrificial layer. Subsequently, we have conducted single-chemical toxicity and multiple choice chemical preference assays on adult Drosophila melanogaster using zinc and acetic acid at various concentrations. Our device has enabled us to 1) demonstrate that Drosophila is capable of sensing the concentration of different chemicals on a PDMS-agar microfluidic device, which plays significant roles in determining oviposition site selection and 2) investigate whether oviposition preference differs between single- and multi-concentration chemical environments. This device may be used to study fundamental and applied biological questions in Drosophila and other egg laying insects. It can also be extended in design to develop sophisticated and dynamic chemical dosing and high-throughput screening platforms in the future that are not easily achievable with the existing oviposition screening techniques.

Neuroscience Research using Small Animals on a Chip: From Nematodes to Zebrafish Larvae

“…Freely moving adult fruit flies inside the microfluidic channels were used to record their oviposition behavior where adult flies laid eggs on their preferential sites on a chemical-induced PDMS substrate (Fig. 4b) [7], and food-finding behavior [57]. Larvae of Danio rerio is also an important animal model that is used to study behavior responses.…”

“…Research performed by researchers showed how fruit fly larvae respond to heavy metals present in food [69]. A group of researchers studied oviposition (i.e., egg-laying) of the adult fruit fly [7,70]. Adult fruit fly has also been studied for observing how they and choose and approach the path for the food [7,57].…”

“…A group of researchers studied oviposition (i.e., egg-laying) of the adult fruit fly [7,70]. Adult fruit fly has also been studied for observing how they and choose and approach the path for the food [7,57]. Danio rerio larvae have been used for behavioral studies as well.…”

“…Besides these qualities, its optical transparency for studying cellular events, and compact nervous system are some attractive features [5,6]. Drosophila Melanogaster, fruit fly, is another attractive model animal to be used at larval and adult stage in the microfluidic system because of the high viability rate in chemical screening tests [7], its small size (2-4 mm at larval stage and 5-8 mm at the adult stage) and the optical transparency at larva stage. Drosophila Melanogaster shares 75% of the known human disease genes [8] and 60% protein homologs with humans [9], which makes it attractive for conducting studies in diverse areas in the neuroscience research field.…”

A microfluidic device to study electrotaxis and dopaminergic system of zebrafish larvae

“…Microfluidic technology has recently emerged as a powerful tool for neural and behavioral investigation of small model organisms such as C. elegans, [35][36][37][38][39][40][41][42] D. melanogaster, [43][44][45][46] and D. rerio. [47][48][49][50][51][52][53] Most recently, various microfluidic techniques have been introduced for precise manipulation, stimulation, and monitoring of zebrafish larvae's behavior.…”