The Keays lab exploits cerebral organoids, advanced light microscopy, and in vivo genetic methods to investigate important questions in developmental and sensory neurobiology.
We are interested in: (1) How mutations in the tubulin and MAST genes cause neurodevelopmental disease?; and (2) How animals detect magnetic and electric fields?
Research
Tubulins, MASTs and Organoids
Consisting of a and b tubulin heterodimers, microtubules are dynamic polymers that play a critical role in multiple aspects of neuronal development. They mediate the separation of sister chromatids in mitosis, they are necessary for nuclear translocation during neuronal migration, and they enable the formation of axonal tracts. Their importance is underlined by the finding that mutations in a host of tubulins genes and microtubule associated proteins cause detrimental neurological disorders. The Keays lab has shown that mutations in the a -tubulin TUBA1A cause severe epilepsy with a smooth cortex, variants in TUBB2B cause excessive cortical folding, and mutations in TUBB5 cause microcephaly. Most recently our genetic studies have revealed that mutations in an uncharacterised microtubule associated serine threonine kinase (MAST1) causes an unusual syndrome characterised by a “mega” corpus callosum. We are interested in understanding how mutations in the tubulin and MAST genes cause neurodevelopmental disease. To do so we are exploiting the power of human cerebral organoids. Drawing on our established network of clinicians, we generate iPSCs, which are then employed to generate “mini brains” (See Figure). We carefully analyse these organoids alongside controls that have been subject to genetic repair using the CRISP-cas9 genome editing system. We use a variety of methods including brain clearing (iDISCO), light sheet microscopy, live cell imaging, and transcriptomic methods to gain insight into the underlying molecular pathology.
Magneto and electroreception
Using maps, compasses, and sextants, mariners in the early 1500's developed the first methods to navigate the open sea; heralding an age of exploration as humanity set sail for thehorizon. Yet long before this time evolution had equipped life on the planet with a biological global positioning system that was far superior to those early navigational tools – the Magnetic Sense. While there is unequivocal behavioural evidence demonstrating that this faculty exists, it is the least understood of all senses. It is a classic scientific mystery: the location of the primary sensors, the underlying biophysical mechanisms, and the neurological basis of the sense are unknown. We hypothesize that animals employ electromagnetic induction within the inner ear to directly translate magnetic information, into a neuronal impulse. Our current work focuses on the a highly sensitive calcium channel CaV1.3, which has been implicated in electroreception. We employ pigeons as model system, and exploit an array of advanced methods in neuroscience including: whole brain iDISCO clearing, 2-photon calcium imaging, RNA sequencing, neuronal tracing, and magnetic activation assays.
Publications
Leca I, Phillips A, Hofer I, Landler L, Ushakova L, Cushion TD, Durnberger G, Stejskal K, Mechtler K, Keays, DA. A proteomic survey of microtubule-associated proteins in a R402H TUBA1A mutant mouse. PLoS Genet 2020. 16(11): e1009104
Nimpf S, Nordmann GC, Kagerbauer D, Malkemper EP, Landler L, Papadaki-Anastasopoulou A, Ushakova L, Wenninger-Weinzierl A, Novatchkova M, Vincent P, Lendl T, Colombini M, Mason MJ, Keays DA. A putative mechanism for magnetoreception by electromagnetic induction in the pigeon inner ear. Curr Biol. 2019 Dec 2;29(23):4052-4059.
Tripathy R, van Dijk T, van Bon B, Gstrein T, Bahi-Buisson N, Paciorkowski A, Pagnamenta A, Taylor J, Terrone G, Vitiello G, D’Amico A, Del Giudice E, Brunetti-Pierri N, Reymond A, Voisin N, Bernstein JA, Farrelly E, Pierson T, Kini U, Leonard T, Mirzaa G, Baas F, Chelly J, Keays DA. Mutations in MAST1 cause mega corpus callosum syndrome and cortical malformations. Neuron. 2018 Dec 19;100(6):1354-1368.
Gstrein T, Edwards A, Přistoupilová A, Leca I, Breuss M, Pilat-Carotta S, Hansen AH, Tripathy R, Traunbauer AK, Hochstoeger T, Rosoklija G, Repic M, Landler L, Stránecký V, Dürnberger G, Keane TM, Zuber J, Adams DJ, Flint J, Honzik T, Gut M, Beltran S, Mechtler K, Sherr E, Kmoch S, Gut I, Keays DA. (2018). Mutations in Vps15 perturb neuronal migration in mice and are associated with neurodevelopmental disease in humans. Nature Neuroscience. Feb;21(2):207-217.
Breuss M, Fritz T, Gstrein T, Chan K, Ushakova L, Yu N, Vonberg FW, Werner B, Elling U, Keays DA. Mutations in the murine homologue of TUBB5 cause microcephaly by perturbing cell cycle progression and inducing p53-associated apoptosis. Development. 2016 Apr 1;143(7):1126-33.
Lauwers, M., Pichler, P., Edelman, NB., Resch, GP., Ushakova, L., Salzer, MC., Heyers, D., Saunders, M., Shaw, J., Keays, DA. (2013). An iron-rich organelle in the cuticular plate of avian hair cells. Curr Biol. 23(10):924-9.
Breuss, M., Heng, JI., Poirier, K., Tian, G., Jaglin, XH., Qu, Z., Braun, A., Gstrein, T., Ngo, L., Haas, M., Bahi-Buisson, N., Moutard, ML., Passemard, S., Verloes, A., Gressens, P., Xie, Y., Robson, KJ., Rani, DS., Thangaraj, K., Clausen, T., Chelly, J., Cowan, NJ., Keays, DA. (2012). Mutations in the β-tubulin gene TUBB5 cause microcephaly with structural brain abnormalities. Cell Rep. 2(6):1554-62.
Treiber CD, Salzer CM, Riegler J, Edelman N, Sugar C, Breuss M, Pichler P, Cadiou H, Saunders M, Lythgoe M, Shaw J, Keays DA. Clusters of iron rich cells in the upper beak of pigeons are macrophages not magnetosensitive neurons. Nature, 2012 Apr 11;484(7394):367-70.
Keays DA, Tian G, Poirier K, Huang G, Siebold S, Cleak J, Oliver P, Washbourne R, Fray M, Harvey RJ, Molnar Z, Pinon M, Dear N, Brown SD, Rawlins JP, Davies KE, Cowan NJ, Patrick Nolan P, Chelly J, Flint J. Mutations in α-tubulin cause defects in neuronal migration in mice and lissencephaly in humans. Cell. 2007 Jan 12;128(1):45-57
