Dr Varsha Singh

Mission

To understand OLFACTION mediated pattern recognition in animals. Olfactory receptors are present not only in our nose but also in our gastro intestinal tract, lungs and other tissue where they help in sensing resident microbiome.

We utilize Caenorhabditis elegans, a nematode lacking traditional pattern recognition receptors (PRRs), to understand pathogen recognition via olfactory GPCRs which might serve as non-canonical PRRs. 

We utilize multidisciplinary approaches to identify microbe associated molecular patterns from pathogens and microbiota (of worms, mice and human) and their sensing by G protein coupled receptors (GPCRs) of C. elegans. We use genetic tools, behaviour analysis, imaging and Alphafold to identify and manipulate GPCR signalling in C. elegans. We also focus on identifying microbial odours which are microbe associate molecular patterns (MAMPs) using gas-chromatography mass spectrometry in combination with microbial genetics. 

We utilize Pseudomonas aeruginosa, a Gram-negative bacterium, to understand how it utilizes its large genomic repertoire of histidine kinase sensors to identify and compete with other microbes, in the context of respiratory infections including pneumonia. 

Open positions

Contact the PI Vsingh001@dundee.ac.uk if you wish to apply for postdoctoral fellowships. If you are interested in working at the cross section of microbiology, immunology and neuroscience, do get in touch. 

PhD positions will be advertised below.

Selected publications

See Google scholar page for a full list of publications.

• Badal, D., Kumar, A., Singh, V., Danny, R. A dynamic fluid landscape mediates the spread of bacteria.  arXiv:2309.05351 DOI: 10.48550/arXiv.2309.05351
• Ambreetha, S., Singh, V. Genetic and environmental determinants of surface adaptations in Pseudomonas aeruginosa.     Microbiology 2023 169 (6), 001335 DOI: 10.1099/mic.0.001335 
• Venkatesh, S., Singh, V. Amphid Sensory neurons of Caenorhabditis elegans orchestrate its survival from broad classes of pathogens. Life Science Alliance 2023 6 (8) DOI: 10.26508/lsa.202301949 
• Pradhan, D., Tanwar, A., Parthsarathy, S. and Singh, V. Toroidal displacement of Klebsiella pneumoniae by Pseudomonas aeruginosa is a unique mechanism to avoid competition for iron. bioRxiv (preprint) https://doi.org/10.1101/2022.09.21.508880
• Filipowicz, A., Aballay, A., Singh, V. Cellular and Organismal Responses to Infections in Caenorhabditis elegans. Elsevier DOI:10.1016/B978-0-12-821618-7.00043-2. 
• Prakash, D., Siddiqui R., Chalasani S., Singh, V. Pyrrole produced by Pseudomonas aeruginosa influences olfactory food choice of Caenorhabditis elegans.  bioRxiv (Preprint)      https://doi.org/10.1101/2022.01.27.477966
• Badal, D., Jayarani, A.V., Kollaran, M.A., Prakash, D., Monisha P., Singh, V. Foraging signals promote swarming in starving Pseudomonas aeruginosa. mBio 2021, 12(5):02033-21. https://doi.org/10.1128/mBio.02033-21 
• Prakash, D., Akhil, M.S., Radhika, B., Venkatesan, R., Chalasani, S.H., Singh, V. 1-Undecene from Pseudomonas aeruginosa is an olfactory signal for flight or fight response in Caenorhabditis elegans. EMBO J. 2021, e106938. https://doi.org/10.15252/embj.2020106938 (OPEN ACCESS)
• Sandhu, A., Badal, D., Sheokand, R., Tyagi, S., Singh V. Specific collagens maintain the cuticle permeability barrier in Caenorhabditis elegans. GENETICS 2021, 217(3):iyaa047. https://doi.org/10.1093/genetics/iyaa047 (OPEN ACCESS)
• Venkatesh, S.R., Singh, V. G protein-coupled receptors: The choreographers of innate immunity in Caenorhabditis elegans. PLoS Pathog 2021, 17(1): e1009151. https://doi.org/10.1371/journal.ppat.1009151 (OPEN ACCESS)
• Dixit, A., Singh, V. The brain-gut axis of longevity. Aging (Albany NY) 2020,12(18):17754-17755. doi: 10.18632/aging.103996. Epub ahead of print. PMID: 32986014; PMCID: PMC7585115. 
• Prakash, P., Abdulla A.Z., Singh, V., Varma, M.M. Swimming statistics of cargo-loaded single bacteria. Soft Matter 2020, 100: 062609. 
• Dasgupta, M., Shashikanth, M.,  Gupta, A.,  Sandhu, A., De, A., Javed, S.,  Singh, V.  NHR-49 transcription factor regulates immuno-metabolic response and 1 survival of Caenorhabditis elegans during Enterococcus faecalis infection. Infec Immun. 2020, 88(8):e00130-20 (full text) https://doi.org/10.1128/IAI.00130-20 (OPEN ACCESS)
• Dixit, A., Sandhu, A., Modi, S., Shashikanth, M., Koushika, S., Watts, J., Singh, V. Neuronal control of lipid metabolism by STR-2 G protein-coupled receptor promotes longevity in C. elegans. AGING CELL 2020, 19(6):e13160 (full text) https://doi.org/10.1111/acel.13160  (OPEN ACCESS)
• Kollaran, M.A., Joge, S., Harshitha, K., Badal,  D., Prakash, D., Mishra, A., Varma, M.M. and Singh, V. Context-Specific Requirement of Forty-Four Two-Component Loci in Pseudomonas aeruginosa Swarming. iScience. 2019 Mar 29;13: 305-317. https://doi.org/10.1016/j.isci.2019.02.028
• Gupta, A., Singh, V., (2017). GPCR Signaling in C. elegans and Its Implications in Immune Response. In Advances in immunology (Vol. 136, pp. 203-226). Academic Press. [Book Chapter], doi: 10.1016/bs.ai.2017.05.002
• Sun, J., Singh, V., Kajino-Sakamoto, R., Aballay, A. Neuronal GPCR controls innate immunity by regulating non-canonical unfolded protein response genes. Science 2011, 332(6030):729-32. doi: 10.1126/science.1203411.
• Styer, K.L., Singh, V., Macosko, E., Steele, S.E., Bargmann, C.I., Aballay, A. Innate immunity in Caenorhabditis elegans is regulated by neurons expressing NPR-1/GPCR. Science 2008, 322(5900), pp.460-464. doi:10.1126/science.1163673
• Singh, V., Aballay, A. Heat-shock transcription factor (HSF)-1 pathway required for Caenorhabditis elegans immunity. Proceedings of the National Academy of Sciences 2006, 103(35), pp.13092-13097. doi:10.1073/pnas.0604050103