Cytoskeleton and motility in plant cells.
Plant cells have an elaborate cytoskeleton of actin filaments, microtubules,
and other proteins. In small algae such as Chlamydomonas these
actually confer motility (swimming), whereas in more advanced plants they are
responsible for such tasks as moving chloroplasts into the best position
to catch the sunlight without being damaged by it. |
Recent techniques such as confocal optical microscopy and high-resolution
scanning electron microscopy have opened up a new perspective on these
structures by providing us with three-dimensional views of their architecture.
Flagellar-associated centrin cytoskeleton of Chlamydomonas,
revealed by immuno-cytochemistry in conjunction with confocal microscopy.
Guy Cox & Teresa Dibbayawan.
Photosynthesis in prokaryotes
Cyanobacteria and prochlorophyta are technically bacteria, and have
a bacterial cell organization, but possess all the photosynthetic chemistry
of green plants.
Some cyanobacteria live in caves, where they survive on very little
light and may play a significant part in precipitating calcite on stalactites
and stalagmites. With Julia James, Bill Allaway, Neville Michie and
Anya Salih I have been studying these using confocal microscopy, electron
microscopy and physiological methods.
On the Great Barrier Reef, and on other coral reefs around the world,
cyanobacteria and their relatives, the prochlorophyta, live in symbiosis
with sponges and ascidians (sea-squirts). The prochlorophytes are
particularly interesting from the point of view of cell evolution since
they seem to be long-lost descendants of the ancestor of the chloroplast
of green plants. With Tony Larkum and Teresa Dibbayawan I have been
looking at the ultrastructure of both prochlorophytes and
symbiotic cyanobacteria on coral reefs.
Anya Salih, Guy Cox, Bill Allaway (Biological Science), Julia James (Chemistry).
3-D reconstruction of two types of optical
data-sets: cyanobacteria (orange colour) imaged by confocal mode, and calcite
crystals (green), imaged by reflection mode of CLSM.
(a) A tilt series of the
flake surface; (b) a top view of the same flake.
Structure and Ecology of Fluorescent Pigments in Corals
An investigation into coral bleaching, using confocal microscopy, electron
microscopy and physiological and ecological techniques.
Anya Salih, Tony Larkum (Biological Science), Guy Cox.
Projection of a 2-photon dataset of Plesiastrea versipora showing the
spatial distribution of the pigments. Blue pigments predominate in the upper layers,
green in lower layers, and the zooxanthellae (red) lie below both.
Second Harmonic Imaging of Collagen
The novel technique of second harmonic imaging provides a high resolution
and extremely sensitive method of studying the three-dimensional distribution
of collagen in tissue.
Left, SHG image of collagen (green) with 2-photon fluorescence of other
Right, conventional stained image of the same area (Masson's
trichrome) - the collagen (c) is much less obvious. f - hair follicle
Guy Cox, Eleanor Kable, Frank Manconi, Mark Gorrell, Paul Xu.
Last updated on July 5th 2017