308
JOHN RUNNSTRÖM
IV. Energy Sources and Some Physicochemical Mechanisms
in the Cortical Changes
A. The Role of Stored Energy
The cortical changes occurring upon fertilization involve a number of
complicated processes. It would be expected that these processes require energy and the energy would be provided by respiration or fermentation. However, the eggs can be fertilized in KCN-containing sea
water (Blumenthal, 1927) or under anaerobic conditions (Barron, 1932;
Harvey, 1930; Runnström, 1930) ; KCN does not inhibit parthenogenetic
activation of starfish eggs (R. S. Lillie, 1941). An inhibitor of glycolysis
such as monoiodoacetic acid does not inhibit the cortical changes. The
rise in respiration occurs in Arbacia punctulata
even in the presence of
0.03 M monoiodoacetic acid (Runnström, 1935).
The problem has been attacked by Okazaki (1956), who pretreated
the unfertilized eggs of Heliocidaris crassispina and Temnopleurus
toreumaticus with the uncouplers 2,4-dinitrophenol (DNP) and sodium azide,
removed these agents by washing with pure sea water, and fertilized
either immediately or after a 40-100 min period in sea water. In the
experiments with DNP, concentrations ranging from 1 X 10~
4 to 5 X
10~
4 M were used. When fertilization occurred immediately after the
transfer from DNP to normal sea water, a considerable inhibition and in
some cases almost complete suppression of the elevation of the fertilization membrane was observed depending on the duration of the pretreatment (80-120 min). If, however, the eggs were kept in sea water after
the pretreatment for 40-100 min, a recovery took place so that almost
all the eggs responded to insemination by normal elevation of the fertilization membrane. In another sea urchin, Pseudocentrotus
depressus,
the described DNP effect was not observed at lower temperatures (1420°C), but at a higher temperature (27-29°C) the inhibitory effect was
obtained. Runnström and Kriszat (unpublished results, 1963) subjected eggs of Psammechinus
miliaris to 5 Χ 10
-5 M DNP for 120 min at
a temperature of 19-20°C and inseminated the eggs while still exposed
to DNP. A fertilization membrane appeared, but the perivitelline space
was narrow and asymmetric. The electron-microscopic examination
showed that a greater number of the cortical particles had not opened up.
As reported in Section ΙΠ,Β, the lamellae are not united in an orderly
way with the vitelline membrane. This latter seems to be weak or even
dissolved, so that the normal sliding of the lamellae along the vitelline
membrane is not possible. The jelly coat is sticky, and many spermatozoa
JOHN RUNNSTRÖM
IV. Energy Sources and Some Physicochemical Mechanisms
in the Cortical Changes
A. The Role of Stored Energy
The cortical changes occurring upon fertilization involve a number of
complicated processes. It would be expected that these processes require energy and the energy would be provided by respiration or fermentation. However, the eggs can be fertilized in KCN-containing sea
water (Blumenthal, 1927) or under anaerobic conditions (Barron, 1932;
Harvey, 1930; Runnström, 1930) ; KCN does not inhibit parthenogenetic
activation of starfish eggs (R. S. Lillie, 1941). An inhibitor of glycolysis
such as monoiodoacetic acid does not inhibit the cortical changes. The
rise in respiration occurs in Arbacia punctulata
even in the presence of
0.03 M monoiodoacetic acid (Runnström, 1935).
The problem has been attacked by Okazaki (1956), who pretreated
the unfertilized eggs of Heliocidaris crassispina and Temnopleurus
toreumaticus with the uncouplers 2,4-dinitrophenol (DNP) and sodium azide,
removed these agents by washing with pure sea water, and fertilized
either immediately or after a 40-100 min period in sea water. In the
experiments with DNP, concentrations ranging from 1 X 10~
4 to 5 X
10~
4 M were used. When fertilization occurred immediately after the
transfer from DNP to normal sea water, a considerable inhibition and in
some cases almost complete suppression of the elevation of the fertilization membrane was observed depending on the duration of the pretreatment (80-120 min). If, however, the eggs were kept in sea water after
the pretreatment for 40-100 min, a recovery took place so that almost
all the eggs responded to insemination by normal elevation of the fertilization membrane. In another sea urchin, Pseudocentrotus
depressus,
the described DNP effect was not observed at lower temperatures (1420°C), but at a higher temperature (27-29°C) the inhibitory effect was
obtained. Runnström and Kriszat (unpublished results, 1963) subjected eggs of Psammechinus
miliaris to 5 Χ 10
-5 M DNP for 120 min at
a temperature of 19-20°C and inseminated the eggs while still exposed
to DNP. A fertilization membrane appeared, but the perivitelline space
was narrow and asymmetric. The electron-microscopic examination
showed that a greater number of the cortical particles had not opened up.
As reported in Section ΙΠ,Β, the lamellae are not united in an orderly
way with the vitelline membrane. This latter seems to be weak or even
dissolved, so that the normal sliding of the lamellae along the vitelline
membrane is not possible. The jelly coat is sticky, and many spermatozoa