Biomedical Engineering Reference
In-Depth Information
Figure 6.3.
Gliding of
M. pneumoniae
. Selected frames from a 10s video were
treated in the same way as those in Figure 6.1 [7, 15]. (See color insert.)
involved in the gliding mechanism of
M. mobile
are present in the genome of
M. pneumoniae
[6, 27, 28]. Therefore, some researchers have suggested that
these groups glide with different mechanisms [6, 29]. What is the definition
of “different” mechanism? Does it mean that they originated from unrelated
systems? I guess that twice of establishment of surface motility is not easy
in the relatively short history of
Mycoplasma
evolution. At the same time, if
the gliding motility is determinant for natural selection of
Mycoplasmas
,even
such extensive evolution might be possible. The answer may be given when
the details of gliding mechanisms are elucidated for both subgroups.
6.2.3 Purpose and Pathogenicity
Why do
Mycoplasma
species glide? So far, eight different mechanisms of ac-
tive bacterial motility have been reported: flagella swimming, synechococcus
swimming, pili motility, slime motility,
Cytophaga
gliding,
Spiroplasma
swim-
ming, and
Mycoplasma
gliding. Other motilities than those of
Mycoplasma
and
Spiroplasma
are all known to be controlled by “two-component systems”,
usually exhibiting chemotaxis [31]. Generally, bacteria move to access nutri-
ents and escape from wastes and predators. However,
Mycoplasma
gliding
