IV.%20Microfluidics%20of%20Cytoplasmic%20Streaming

1
IV. Microfluidics of Cytoplasmic Streaming
R E Goldstein
www.damtp.cam.ac.uk/user/gold
www.youtube.com/Goldsteinlab
2
The Discovery of Streaming
Chara
Internodal cell after osmotic stress
Flow pattern
(Digital Images from the British Library)
3
Cytoplasmic Streaming (Cyclosis)

• Fluid-like circulation of cellular sap
  (cytoplasm)
• Organelles coated with myosin are transported
  along actin filaments
• Steady velocities up to 100 µm/s

ProtozoaParamecium, Stentor, Allogromia, ...
Plants (hair cells, pollen tubes)
Tradescantia, Urtica, Cucurbita,
Algae Chara, Nitella, Acetabularia,
Rotational streaming
Multi-striate streaming
Circulation streaming
4
Architecture of Chara corallina
5
Further Details
6
Cell Geometry
7
History

• Streaming in Nitella known since 18th century
  (Corti 1776)
• Kamiya Kuroda (1956) Cytoplasm moves as a
  gel, sliding along wall
• Pickard (1972) Shear flow in vacuole

Kamiya Kuroda, Bot Mag Tokyo, 1956

• Model system for streaming and plant motility.
• Kamitsubo/Shimmen (1994) Myosin XI purified
  from Chara/Lilys
• Robust under surgery Ideal for studies on
  membrane transport

Tominaga et al, EMBO J, 2003
8
Cytoplasmic Streaming (the Movie)
Goldstein, Tuval, van de Meent, PNAS 105, 3663
(2008) van de Meent, Tuval, and Goldstein, PRL
101, 178102 (2008)
9
Microfluidics of Cytoplasmic Streaming
Jan-Willem van de Meent
10
Cytoplasmic Streaming (Nodal Cell)
Nodal cell (40x)
11
Plasmodesmata
Courtesy of Jeanmarie Verchot-Lubicz
Proteins identified in plasmodesmata include
centrin, calreticulin, myosin VIII, and calcium
dependent protein kinases. Models suggest
plasmodesmata are contractile.
Studies using GFP indicate plasmodesmata have
closed, open, and dilated (gated) states.
Image from Ding and Lucas
12
Myosin Translocation on Actin
Matthew L. Walker, Stan A. Burgess, James R.
Sellers, Fei Wang, John A. Hammer III, John
Trinick Peter J. Knight. Two-headed Binding of
a Processive Myosin to F-actin. Nature, 405,
804-807 (2000).
13
Some Details
14
Chiral Flows
15
Aspects of the Velocity Field
16
Velocities
longitudinal
transverse
Data from Kamiya Kuroda Numerical
results (solid curve)
17
Transient Uptake Dynamics
18
Systematics
19
Boundary Layer Properties
20
Natures Microfluidic Mixer
21
Connections with Growth Dynamics (N. axillaris)
Data from P. Green
22
Magnetic Resonance Velocimetry of Chara
van de Meent, Sederman, Gladden, Goldstein,
preprint (2009)
23
Cross-sectional Profiles
24
Average Profiles
25
A Window Into Streaming
Photo overexposure of chloroplasts leads to their
detachment and subsequent reconstruction of
cytoplasmic streaming (method due to N.S. Allen)
26
A Window Into Streaming (Close-up)
27
Tonoplast Undulations in GFP-Labelled Arabidopsis
Cutler, Ehrhardt, Griffitts, Somerville PNAS 97,
3718 (2000)
20 µm
4.5 s/frame 10 frames/s
28
Observation of Shear-Induced Flows in Vesicles
Vézy, Massiera, Viallat, Soft Matter (2007)
Questions Shear transmission to inner
fluid Possible instabilities
Topological rearrangements
29
Towards a Quantitative Understandingof Tonoplast
Dynamics
Sarah L. Keller (U Washington) Marco Polin
(DAMTP)