[Arabidopsis] PhD studentship in Oxford UK

John Runions via arab-gen%40net.bio.net (by jrunions from brookes.ac.uk)
Tue May 1 11:55:30 EST 2007


   Hello everybody,
   A PhD studentship is available to study organelle dynamics during cell
   division in the Arabidopsis root.  If any of you have or know of
   students who might be interested in this, would you please bring it to
   their attention.  Details are below.  The full project description and
   application procedure can be found on the Oxford Brookes University
   website.
   Regards, John
   
   
   PhD Research Studentship: Organellar fate during cytokinesis
   
   Supervisors: Dr John Runions, Prof Chris Hawes, Dr David Evans
   
   Eligibility: Applicants require a good Honours degree (2.1 or
   equivalent) and either have been educated to degree level through the
   medium of English or have TOEFL 600 (250) / IELTS 7 or equivalent
   
   Value p.a. £11,500 bursary, & fees
   
   Closing Date: 21st May
   Interviews will be held on either June 6th, 7th or 8th
   
   Project Description
   
   Background: Little is known about the mechanisms that determine
   organellar fate during cytokinesis. As cells enter mitosis, the
   nuclear envelope breaks down and rearrangements occur in the structure
   of the cytoskeleton and endoplasmic reticulum (ER). In addition, Golgi
   bodies, peroxisomes and mitochondria must re-duplicate so that
   daughter cells are equally partitioned. We have in place techniques
   for studying cell divisions at high resolution in a developmental
   context. The arabidopsis root meristem is an ideal system in which to
   study cell division in situ. Fluorescent protein marking of organelles
   combined with confocal microscopy and image analysis of tissue 3D/4D
   reconstructions will enable us to answer a number of questions about
   organelle behaviour in the cell division zone. For example, i) what
   role does the ER play in cell plate and nuclear envelope formation,
   and ii) when do Golgi bodies re-duplicate and how are they partitioned
   between daughter cells?
   
   Project:
   
   1) Cytokinesis in wild-type roots. Arabidopsis roots are ideal for
   imaging when grown in coverslip-bottomed containers as they remain
   healthy and continue to grow during observation. The student will
   first learn high resolution live-cell imaging techniques by studying
   cytokinesis in arabidopsis roots that have been stably transformed
   with H2B-YFP which is a histone marker (Kurup et al, 2006) (fig.1).
   This marker allows observation of nuclei during prophase and of
   chromatin during other phases of the cell cycle. Co-Supervisor's
   laboratories have fluorescent markers for other organelles. These will
   be co-transformed into the nuclear-marking line in appropriate
   combinations to describe the dynamics and disappearance / reappearance
   of organelles during the cell cycle. We will concentrate on behaviour
   of the ER, nuclear envelope and Golgi bodies during this phase. We
   will use a cyclin marker that indicates entry into metaphase prior to
   chromatin condensation for ease of targeting about-to-divide cells in
   subsequent experimentation.
   
   2) Photoactivation of organelles during mitosis. JR has developed a
   technique for monitoring organelle development and dynamics using
   photoactivatible fluorescent protein marking (Runions et al., 2006).
   This technique utilises the short wavelength laser of the confocal
   microscope system to either switch fluorescent proteins on or to
   change their colour. The student will activate regions of ER both
   proximal and distal to the site of cell-plate formation at different
   phases of mitosis to monitor the contribution of existing ER into the
   new cell plate and into the nuclear envelope. In addition, Golgi
   bodies marked with the `kaede' fluorescent protein will be colour
   photoswitched so that we can assess their dynamics during daughter
   cell partitioning in later stages of mitosis.
   
   3) Cytokinesis defective mutants. Several mutant lines of arabidopsis
   have altered tissue morphology due to defects in cytokinesis (Jergens,
   2005). These are distinct from cell-wall and cytoskeleton mutants and
   seem to affect cell division because of defects in secretory pathway
   function. Genes that play a role in cell division and that affect root
   patterning include SCD1 (At1g49040), a homologue of the guanine
   nucleotide exchange factors that regulate Rab GTPases and which affect
   intracellular protein transport (Falbel et al., 2003), and several
   including the KEULE-like loci which are Sec1p homologues that play a
   role in membrane fusion (Sollner et al., 2002). Mutant arabidopsis
   lines that are defective for these genes will be crossed with the
   H2B-YFP nuclear marking line so that the role of the ER in defective
   cytokinesis can be monitored using the techniques described above.
   
   Ultimately, the student will report on the role of ER, and on the
   behaviour of Golgi bodies and the nuclear envelope during normal and
   defective cell division. This will be a significant contribution to
   our understanding of cell function.
   
   References:
   
   Falbel, TG et al. (2003) SCD1 is required for cytokinesis and
   polarized cell expansion in Arabidopsis thaliana. Development 130:
   4011-4024.
   
   Jergens, G (2005) Cytokinesis in higher plants. Annual Review of Plant
   Biology 56: 281-299.
   Kurup, K et al. (2006) Marking cell lineages in living tissues. Plant
   Journal 42: 444-453.
   Runions, J et al. (2006) Photoactivation of GFP reveals protein
   dynamics within the endoplasmic reticulum membrane. Journal of
   Experimental Botany 57: 43-50.
   Sollner, R et al. (2002) Cytokinesis defective mutants of arabidopsis.
   Plant Physiology 129: 678-690.
   
   An opportunity to develop teaching skills in higher education may be
   included in the training available with this studentship.
   
   To discuss the project and for any other scientific queries contact
   John Runions ([1]jrunions from brookes.ac.uk). 
   
   To apply for this project, applicants should quote the title of the
   studentship and include a letter of application, CV and the names and
   addresses of two academic referees (one of whom can also comment on
   the applicant's potential for teaching)
   
   Applications will only be accepted by post, and not by email, to:
   
   Ms Angela Robinson
   Research Administrator
   School of Life Sciences
   Oxford Brookes University
   Headington
   Oxford
   OX3 0BP
   
   Tel: +44 (0) 1865 483295
   
   Email: Ms Angela Robinson
   
   --
   
   *********************************
   C. John Runions, Ph.D.
   School of Life Sciences
   Oxford Brookes University
   Oxford, UK
   OX3 0BP
   email:  [2]jrunions from brookes.ac.uk 
   phone: +44 (0) 1865 483 964
   
   web: [3]http://www.brookes.ac.uk/lifesci/runions/HTMLpages/index.html
   
   
   New - Oxford Brookes Master's in [4]Bioimaging with Molecular
   Technology

References

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