NON-FILAMENTOUS AQUATIC FUNGI
49
movement of Blastocladiella's
tail (not to mention frequency control of
its flagellar beat; Hoffmann-Berling, 1959) involves use of adenosine
triphosphate, as seems to be the case in several other organisms (Bishop,
1958; Tibbs, 1962), then the spores of B. emersonii would have to be
provided with a steady ration of this substance for extended periods of
time. The intimate contact between the giant mitochondrion and the
sheath-less flagellum is so striking we cannot help but theorize that a
cause-and-effect relationship must exist between them ; certainly, it is a
logical possibility and can hardly be overlooked. However, there is no
direct experimental evidence that the two are linked by an energy
transfer mechanism. With homogeneous, synchronized, populations of
swimming spores now available (see later), it should be forthcoming.
Finally, one aspect of the spore itself deserves re-emphasis. Its
internal structure is maintained so long as it does not germinate ; there
is no obvious 'internal autolysis' of organelles to disrupt its structural
integrity so long as it is swimming. Thus, a condition of starvation delays
differentiation
of the spore into a germling, after which exponential
growth follows inevitably. Thus, this would appear to be an example of
substrate control (albeit in a negative sense) of differentiation, whereby
no new, internal, soluble pools (and all the 'noise' attached thereto) are
'forced' upon the spore beyond its normal needs. If the synthesis of
protein and the sequence of amino-acids contained therein is controlled
by ribosomes, and if nascent proteins of the latter (Kihara et al., 1961)
are precursors of the soluble protein of the growing cell, then the
aggregation of all the ribosomal components of the spore into a tightly
packaged, membraned organelle could well have a profound effect upon
such activities. Something more nutritious—more disturbing might be
the better term—than plain water would be necessary to initiate its
disintegration into ribosomal particles of more normal disposition.
B. The Spore Germination Stage
When at last the spore stops swimming and settles down, it indulges
in a series of curious and droll gesticulations preparatory to its germination (Cantino et al., 1963) ; in brief, these are as follows :
(a) The flagellum stops its normal, lashing beat.
(b) It then begins to vibrate back and forth ; there is no directional,
propulsive force involved, however (unless the spore possesses some
mysterious braking device), for the spore remains essentially stationary.
(c) Then, the flagellum ceases all detectable activity, becomes quite
still, and stiffens up ; the body of the spore begins to take on a rather
irregular, somewhat spherical shape.
(d) After this, the flagellum sweeps around in a wide arc, stops in this
position, and remains there.
49
movement of Blastocladiella's
tail (not to mention frequency control of
its flagellar beat; Hoffmann-Berling, 1959) involves use of adenosine
triphosphate, as seems to be the case in several other organisms (Bishop,
1958; Tibbs, 1962), then the spores of B. emersonii would have to be
provided with a steady ration of this substance for extended periods of
time. The intimate contact between the giant mitochondrion and the
sheath-less flagellum is so striking we cannot help but theorize that a
cause-and-effect relationship must exist between them ; certainly, it is a
logical possibility and can hardly be overlooked. However, there is no
direct experimental evidence that the two are linked by an energy
transfer mechanism. With homogeneous, synchronized, populations of
swimming spores now available (see later), it should be forthcoming.
Finally, one aspect of the spore itself deserves re-emphasis. Its
internal structure is maintained so long as it does not germinate ; there
is no obvious 'internal autolysis' of organelles to disrupt its structural
integrity so long as it is swimming. Thus, a condition of starvation delays
differentiation
of the spore into a germling, after which exponential
growth follows inevitably. Thus, this would appear to be an example of
substrate control (albeit in a negative sense) of differentiation, whereby
no new, internal, soluble pools (and all the 'noise' attached thereto) are
'forced' upon the spore beyond its normal needs. If the synthesis of
protein and the sequence of amino-acids contained therein is controlled
by ribosomes, and if nascent proteins of the latter (Kihara et al., 1961)
are precursors of the soluble protein of the growing cell, then the
aggregation of all the ribosomal components of the spore into a tightly
packaged, membraned organelle could well have a profound effect upon
such activities. Something more nutritious—more disturbing might be
the better term—than plain water would be necessary to initiate its
disintegration into ribosomal particles of more normal disposition.
B. The Spore Germination Stage
When at last the spore stops swimming and settles down, it indulges
in a series of curious and droll gesticulations preparatory to its germination (Cantino et al., 1963) ; in brief, these are as follows :
(a) The flagellum stops its normal, lashing beat.
(b) It then begins to vibrate back and forth ; there is no directional,
propulsive force involved, however (unless the spore possesses some
mysterious braking device), for the spore remains essentially stationary.
(c) Then, the flagellum ceases all detectable activity, becomes quite
still, and stiffens up ; the body of the spore begins to take on a rather
irregular, somewhat spherical shape.
(d) After this, the flagellum sweeps around in a wide arc, stops in this
position, and remains there.