Biomedical Engineering Reference
In-Depth Information
Figure 6.1.
Gliding of
M. mobile
. Selected frames from 4s of footage were differently
colored from purple to red and integrated into one image [7, 11]. The traces in the
image show gliding speed, direction of gliding, and time relations with other traces.
Reprinted from [11]. Copyright 2005 National Academy of Sciences, U.S.A. (See
color insert.)
6.2.2 Phylogenetic Relationship of Gliding
Mycoplasmas
with
Other Surface Motile Organisms
The gliding motility of
Mycoplasmas
may remind researchers working on eu-
karyotic motility of the motility of an amoeba or nematode sperm, because
they move on solid surfaces such as glass and plastics. However,
Mycoplasma
gliding is unlikely to share structures or mechanisms with eukaryotic motility,
because
Mycoplasmas
are phylogenetically very distant from eukaryotes.
What about the relationship with the surface motility of other bacteria?
The surface motility of bacteria was first discovered more than 130 years ago
and has been reported for a wide variety of species [17]. The motility of most
of these species has been lumped together as “gliding motility”, and the mech-
anisms responsible have remained unclear. However, recent studies using new
experimental techniques have led to the classification of gliding motility into
three groups, excluding
Mycoplasmas
(see Figure 6.5) [18, 17, 19, 20, 21]. The
first, pili motility, includes the twitching motility of
Pseudomonas aeruginosa
,
the social (gliding) motility of
Myxococcus xhansus
, and the gliding motility
of some species of cyanobacteria [18, 20]. These bacteria extend Type 4 pili
