Magcha kummasa - Come Join US

We are always interested in host enthusiastic students and postdocs. We currently have two potential funded PhD opportunities to join us and work in a vibrant research environment, please contact Dr Ko-Fan Chen directly. For students who are considering self-funded possibility, please also see below sections for the small list of external fundings

Potential PhD project A

Genetic mechanism underlying pigmentation, vision and sleep

Melanin is a pigment in animal skins and cuticles. Naturally occurred mutations in genes in melanin synthesis pathways cause condition called albinism across animal kingdom. We and others recently found that gene orthologues of oca2 and slc45a2, the two melanin synthesis genes, express in the nervous system. The mutations of these genes cause sleep and vision phenotype in the fruit fly Drosophila and cavefish (1, 2). Sleep is required for regulating neural activity. Evidence indicates that vision and sleep regulate each other (3-5). Our finding therefore suggests an evolutionary conserved function of pigmentation genes in nervous system. This PhD project, therefore, aims to use the highly genetically editable model, Drosophila, to uncover this novel sleep controlling mechanism by the following objectives.

1) Neural circuits: using scRNA-seq data (1), the student will identify cells enriched with oca2 and slc45a2 in the fly brain. Vertebrate and fly oca2 and slc45a2 transgenes will be reintroduced into these cells and verify if sleep and visual phenotype in oca2 and slc45a2 mutants is reversed. Connectome (6) will then be used to define neural connection between oca2/slc45a2-expressing neurons and the sleep controlling circuits.

2) Neuronal function: oca2 and slc45a2 are predicted to control sleep-related neurotransmission by regulating neuronal pH and Cl- (1). Using fluorescence reporter in brain imaging, the student will verify whether oca2/slc45a2 mutations cause altered pH and Cl- levels.

3) Sleep and vision interaction: to verify if sleep modifies the visual defect in oca2/slc45a2 mutants, the student will perform electroretinogram before and after artificially enhancing the mutants’ sleep by drug feeding or optogenetically activating sleep promoting circuits.

Reference:

(please use ID provided to locate references on https://europepmc.org/):

1. PPR: PPR1243431. 2. PMID: 34293332. 3. PMID: 31100151. 4. PMID: 30355611. 5. PMID: 41815955. 6. PMID: 39638801

Potential PhD project B

Assessing impact of artificial light at night (ALAN) on insect sleep

Artificial lighting at night (ALAN) is a major contributor to the "insect apocalypse". Loss of insects has profound implications on the sustainability of ecosystems and food security [1]. However, ALAN’s impact on insect fitness beyond increasing predation for nocturnal insects is less clear. Night light causes sleep loss in diurnal insects [2,3] and can lead to defects in reproductive and visual performance [3,4]. We recently showed that insect sleep is dynamically modulated by light and vision [5], but it is unclear what colour wavelength and intensity of the lighting are the most sleep-depriving at night. Guidelines to limit obtrusive night light are available from Institution of Lighting Professionals (ILP) (GN01) to avoid their impacts on environment for defined environmental zone. Whether the same guideline is suitable for insects is unclear. Moreover, our understanding of the impact of ALAN on sleep in key pollinators like bees and hoverflies are limited.

This PhD project therefore aims to collaborate with ILP to implement real-life lighting conditions to investigate the effect of duration, intensity, and colour spectrum of artificial lighting on insect sleep. The experiment will be performed on the established insect sleep model, Drosophila species, taking advantage of their diverse niches[6], and on a key pollinator, hoverfly Episyrphus balteatus[7].

Working with ILP, the student will conduct three research objectives:

1) To define sleep for non-melanogaster fruit fly and the hoverfly by the established sleep assays (Figure 1A) [5,8]

2) To record sleep alteration upon exposure of ALAN that mimics luminance limit, scatter, colour temperature and spectrum for each environmental zone (E0-E4, Figure 1B) to the hoverfly and four Drosophila species spanning climate, light and diet niches (D. melanogaster, D.phalerata, D. buzzatii, and D. grimshawi).

3) To verify impact of ALAN-mediated sleep loss on visual-related behaviour and physiology (Figure 1C)[5]

Together, the project studies how ALAN affects insect sleep with a focus on a key pollinator species by combining high-throughput insect behaviour and electrophysiology assays and knowledge from insect biologists and lighting industry experts. The outcome is likely to lead to easily implemented recommendations to add to the ILP guidance for outdoor lighting.

Reference:

1.doi:10.1016/j.biocon.2019.108259, 2. doi:10.1038/s41598-024-73378-9, 3. doi:10.1016/j.cbpc.2025.110349, 4. doi:10.1242/jeb.191429, 5. doi:10.1016/j.nbscr.2026.100146, 6. doi:10.1242/jeb.143008, 7. doi:10.1016/j.cub.2019.05.036, 8. doi:10.7554/eLife.38114

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