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Dr Melinda Modrell

I am investigating the molecular mechanisms underlying vertebrate electroreceptor development in a wide range of species to better understand the evolution of vertebrate sensory receptor cell diversification.
Dr Melinda Modrell

Research Associate


Office Phone: +44 (0) 1223 339558

Research Interests

We have five primary senses: sight, smell, taste, touch and hearing. Our sense of hearing (and balance) results from the movement of tiny “hairs” on specialized sensory “hair cells” in our inner ears, and additionally in fishes and aquatic amphibians, in small sense organs (neuromasts) arranged in characteristic lines over the head and body. These “lateral line” mechanosensory hair cells are used to detect local water flow in the surrounding water for behaviours such as schooling and prey/predator detection. However, an entire second set of modified hair cells, which detect changes in weak electric fields in water, is also present in most aquatic vertebrate groups, but lost in frogs and most modern bony fishes, as well as land vertebrates. Interestingly, electrosensory hair cells (electroreceptors) independently evolved at least twice in two different groups of teleosts, including catfishes and “electric fishes”. Electroreceptors are collected in tiny sense organs (ampullary organs), recessed into the skin at the base of canals filled with a mucous jelly with very low electrical resistance. Electroreception is used for hunting live prey, for orientation (e.g. for long distance migration relative to the earth’s magnetic field) and, in some species, for communication. Although much is known about mechanosensory hair cell development, very little is known about the development of electroreceptors. My overall aim is to investigate the embryological origins and molecular mechanisms underlying electroreceptor development in species from a variety of electroreceptive vertebrate groups, including paddlefish, salamanders, cartilaginous fishes (e.g. skates and sharks) and catfishes. Overall, this research will shed light on the mechanisms leading to the diversification of sensory receptor cells types during evolution.

Collaborators

Marcus Davis, Kennesaw State University, GA, USA
Andrew Gillis, Department of Zoology, University of Cambridge
Harold Zakon, University of Texas at Austin, TX, USA

Key Publications

Modrell MS, Hockman D, Uy B, Buckley D, Sauka-Spengler T, Bronner ME, Baker CVH, (2014), A fate-map for cranial sensory ganglia in the sea lamprey, Dev. Biol, 385(2): 405-416

Gillis JA, Modrell MS, Baker CVH, (2013), Developmental evidence for serial homology of the vertebrate jaw and gill arch skeleton, Nat. Commun, 4: 1436

Baker CVH, Modrell MS, Gillis JA, (2013), The evolution and development of vertebrate lateral line electroreceptors, J. Exp. Biol, 216: 2515-2522

Gillis JA, Modrell MS, Northcutt RG, Catania KC, Luer CA, Baker CVH, (2012), Electrosensory ampullary organs are derived from lateral line placodes in cartilaginous fishes, Development, 139: 3142-3146

Modrell MS, Baker CVH, (2012), Evolution of electrosensory ampullary organs: conservation of Eya4 expression during lateral line development in jawed vertebrates, Evol. Dev, 14 (3): 277-285

Gillis JA,* Modrell MS,* Baker CVH, (2012), A timeline of pharyngeal endoskeletal condensation and differentiation in the shark, Scyliorhinus canicula, and the paddlefish, Polyodon spathula, Journal of Applied Ichthyology, 28 (3): 341-345 [Invited submission for special issue: Interdisciplinary approaches in fish skeletal biology]. *equal contribution

Modrell MS, Bemis WE, Northcutt RG, Davis MC, Baker CVH, (2011), Electrosensory ampullary organs are derived from lateral line placodes in bony fishes, Nat. Commun, (2): 496

Modrell MS, Buckley D, Baker CVH, (2011), Molecular analysis of neurogenic placode development in a basal ray-finned fish, Genesis, 49 (4): 278-94

Above: In situ hybridization of a feeding stage paddlefish larva for a voltage-gated calcium channel subunit gene showing expression in both electrosensory and mechanosensory hair cells.

Above: Confocal slice through the sensory epithelium of a paddlefish electrosensory ampullary organ stained with the nuclear marker DAPI (cyan) and the F-actin marker phalloidin (green).