University of Dundee

Dr Jens Januschke

Dynamics of cell polarisation
Position: 
Wellcome Trust and Royal Society Sir Henry Dale Fellow, Deputy Head of the Division of Cell & Developmental Biology
Address: 
School of Life Sciences, University of Dundee, Dundee
Full Telephone: 
+44 (0) 1382 386169, int ext 86169
Email: 

Research

 Establishment of cell polarity in rapidly dividing Drosophila stem cells

The ability to generate different cell types is a fundamental feature of multicellular life forms.  Asymmetric cell division (ACD) is an important process that helps to produce the repertoire of cell types. ACD is particularly important for the function of stem cells as it provides the bases for self-renewing fate generating divisions during development as well as for tissue homeostasis in the adult. Faulty stem cell division has dramatic consequences for the integrity of organisms as it can compromise normal initiation and maintenance of tissues. We are interested in the dynamics of ACD in stem cells. A long-term goal is to understand how cycling stem cells robustly control ACD to prevent errors in cell fate generation.

We use Drosophila neural stem cells of the developing central nervous system called, neuroblasts, to study this process. Neuroblasts are highly proliferative and provide a well-characterised model system for ACD.  As in many other stem cells, ACD in neuroblasts relies on the establishment of a polarity axis that governs the orientation of the mitotic spindle to transmit cell fate information differentially to the resulting daughter cells upon cytokinesis (see Video 1). However, progression through the cell cycle is accompanied by dramatic subcellular rearrangements (Video 1), raising the question of how continuity of cell polarity is ensured from one cell cycle to the next.

Imaging living neuroblasts in primary cell culture as well as in whole mount explants of the developing brain, we document and measure the dynamics of cell polarisation during consecutive neuroblast cycles. We focus particularly on the subcellular localisation of mRNA’s to determine their contribution to the establishment of cell polarity and cell fate specification.

Publications

Hannford, M.R., Loyer, N., Tonelli, F., Zoltner, M. and Januschke, J. (2019) A chemical-genetics approach to study the role of atypical Protein Kinase C in Drosophila. Development 146, dev170589.
doi/10.1242/dev.170589
PMCID 6361133
PMID 30635282
 
Hannaford, M.R., Ramat, A., Loyer, N., Januschke, J. (2018)  aPKC-mediated displacement and actomyosin-mediated retention polarize Miranda in Drosophila neuroblasts. eLife. 7:1-22.
doi/10.7554/eLife.29939.001
PMCID 5783611
PMID 29364113
 
Clemente, G.D., Hannaford, M.R., Beati, H., Kapp, K., Januschke, J., Griffis, E.R., Müller, H.A.J. (2018) Requirement of the Dynein-Adaptor Spindly for Mitotic and Post-Mititotic Functions in Drosophila. Journal of Developmental Biology. 6(2). 
Doi/10.3390/jdb6020009
PMCID 6027351
PMID 29615558
 
Loyer, N. Januschke, J. (2018) The last-born daughter cell contributes to division orientation of Drosophila larval neuroblasts. Nature Comm 9:3745.
doi/10.1038/S41467-018-06276-0
PMCID 6138640
PMID 30218051
 
Popow, O., Tatham, M.H., Paolo, J.A., Rojas-Fernandez, A., Loyer, N., Newon, I.P., Januschke, J., Haigis, K.M., Näthke, I. (2018) Identification of Endogenous Adenomatous Polyposis Coli Interaction Parners and β-Catenin-Independent Targets by Proteomics.
doi.org/10.1101/258400
 
Januschke, J. and Wodarz, A. (2017) Notch Signaling: Where Is the Action? Current biology: CB. 27, R760-R762. 
doi.org/10.1016/j.cub.2017.06.072
PMID  28787607
 
Ramat, A., Hannaford, M. and Januschke, J. (2017) Maintenance of Miranda Localization in Drosophila Neuroblasts Involves Interaction with the Cognate mRNA. Current Biology: CB. 27, 2101-2111 e2105.
doi/10.1016/j.cub.2017.06.016
PMCID 5526833
PMID 28690114
 
Pampalona, J., Januschke, J., et al. (2015). Time-lapse recording of centrosomes and other organelles in Drosophila neuroblasts. Methods Cell Biol 129: 301-315.
doi/10.1016/bs.mcb.2015.03.003
PMID 26175445
 
Januschke, J. and Nathke, I. (2014). Stem cell decisions: a twist of fate or a niche market? Seminars in Cell Dev Biol 34: 116-123.
doi/10.1016/j.semcdb.2014.02.014 
PMCID PMC4169664
PMID 24613913
 
Januschke, J., Reina, J., et al. (2013) Centrobin controls mother-daughter centriole asymmetry in Drosophila neuroblasts. Nat Cell Biol 15(3): 241-248.
doi/10.1038/ncb2671
PMID 23354166
 
Januschke, J., Llamazares, S., et al. (2011) Drosophila neuroblasts retain the daughter centrosome. Nat Commun 2: 243. 
doi/10.1038/ncomms1245
PMCID 3072095
PMID 21407209
 
Wang, C., Li, S., Januschke, J., et al. (2011) An ana2/ctp/mud complex regulates spindle orientation in Drosophila neuroblasts. Dev Cell 21(3): 520-533. 
doi/10.1016/j.devcel.2011.08.002
PMID 21920316
 
Januschke, J. and Gonzalez, C. (2010) The interphase microtubule aster is a determinant of asymmetric division orientation in Drosophila neuroblasts. J Cell Biol 188(5): 693-706.
doi/10.1083/jcb.200905024
PMID 20194641