NON-FILAMENTOUS AQUATIC FUNGI
51
the swimming spore—or is it more likely, on the other hand, that protein
synthesis (and therefore adaptation via induced enzyme formation)
cannot occur in motile spores? It is a fact (Cantino, unpublished; see
also, Cantino and Hyatt, 1953a) that spores of Blastocladiella
which
swim about for long periods of time are seldom capable of germination,
while populations of spores which settle quickly display great viability.
Thus, perhaps the spore is a sort of all-or-none affair, incapable of
adaptation and placed thereby in the position where it must either
retract its flagellum before its internal food supply has reached some
critical level or, having gone beyond this point, swim about until all
endogenous reserves are gone and then die. We do not have the answers,
but there is no reason why some of them cannot be obtained.
And finally, what of the resorbed flagellar material which, one might
guess, would be predominantly proteinaceous as it appears to be in the
flagella of other organisms (Kerridge, 1961; Koffler, 1957). Since
Blastocladiella emersonii does not discard it, can we reasonably assume
it has a function, or is it just a useless appendix which, once pulled in per
force of evolutionary habit, is disposed of with no distinct advantage—
and possibly even disadvantage—to the cell?
Whatever explanations may one day be forthcoming, these various
events set the stage for all that is to follow in the life-history of the
organism.
C. Synchronized Single-Generation Cultures
Studies during the past few years have repeatedly revealed the
practical utility of massive, submerged, synchronized, single-generation
cultures of Blastocladiella
emersonii (Cantino, 1961a). It would be
advisable therefore, to describe the methodology in some detail before
moving on to growth phenomena.
When a spore of B. emersonii germinates on suitable substrata
solidified with agar (e.g., PYG or YpSs agar; Difco Labs., Detroit, Mich.),
it develops into a two-celled plant (Fig. 2). The lower cell, however, is
apparently devoid of protoplasmic contents ; thus, it is convenient to
relate the phenomena which follow to the development of a single cell.
At maturity, the protoplast in the terminal cell is subdivided into spores
(on the average, nearly a thousand ; Cantino and Hyatt, 1953a) which, in
turn, are liberated through exit pores onto the surface of the agar
medium. If this surface is dry, as is usually the case, such spores
germinate immediately around the parent cell to produce a second
generation clone (Cantino, 1951; Cantino and Hyatt, 1953a) of Blastocladiella. However, the culture can be flooded with water before this
time; cells are thus induced to liberate their spores somewhat prematurely, the size of the thallus at the time of discharge (and thus the
51
the swimming spore—or is it more likely, on the other hand, that protein
synthesis (and therefore adaptation via induced enzyme formation)
cannot occur in motile spores? It is a fact (Cantino, unpublished; see
also, Cantino and Hyatt, 1953a) that spores of Blastocladiella
which
swim about for long periods of time are seldom capable of germination,
while populations of spores which settle quickly display great viability.
Thus, perhaps the spore is a sort of all-or-none affair, incapable of
adaptation and placed thereby in the position where it must either
retract its flagellum before its internal food supply has reached some
critical level or, having gone beyond this point, swim about until all
endogenous reserves are gone and then die. We do not have the answers,
but there is no reason why some of them cannot be obtained.
And finally, what of the resorbed flagellar material which, one might
guess, would be predominantly proteinaceous as it appears to be in the
flagella of other organisms (Kerridge, 1961; Koffler, 1957). Since
Blastocladiella emersonii does not discard it, can we reasonably assume
it has a function, or is it just a useless appendix which, once pulled in per
force of evolutionary habit, is disposed of with no distinct advantage—
and possibly even disadvantage—to the cell?
Whatever explanations may one day be forthcoming, these various
events set the stage for all that is to follow in the life-history of the
organism.
C. Synchronized Single-Generation Cultures
Studies during the past few years have repeatedly revealed the
practical utility of massive, submerged, synchronized, single-generation
cultures of Blastocladiella
emersonii (Cantino, 1961a). It would be
advisable therefore, to describe the methodology in some detail before
moving on to growth phenomena.
When a spore of B. emersonii germinates on suitable substrata
solidified with agar (e.g., PYG or YpSs agar; Difco Labs., Detroit, Mich.),
it develops into a two-celled plant (Fig. 2). The lower cell, however, is
apparently devoid of protoplasmic contents ; thus, it is convenient to
relate the phenomena which follow to the development of a single cell.
At maturity, the protoplast in the terminal cell is subdivided into spores
(on the average, nearly a thousand ; Cantino and Hyatt, 1953a) which, in
turn, are liberated through exit pores onto the surface of the agar
medium. If this surface is dry, as is usually the case, such spores
germinate immediately around the parent cell to produce a second
generation clone (Cantino, 1951; Cantino and Hyatt, 1953a) of Blastocladiella. However, the culture can be flooded with water before this
time; cells are thus induced to liberate their spores somewhat prematurely, the size of the thallus at the time of discharge (and thus the