VITELLINE MEMBRANE AND CORTICAL PARTICLES 261
a trypsin-sensitive reception system which mediates the effective attachment of the spermatozoon. An activating system, on the other hand, is
not affected by the trypsin pretreatment. It was shown by the same
authors that treatment of the egg with neuramidase had no apparent
effect on the egg surface {loc. cit.). Earlier Runnström et al. (1943) had
shown that the fertilization was not affected by a hyaluronidase from
bull testicle (preparation by Hahn, 1943).
The distinction between a reception and an activation system is in
keeping with results obtained by Perlmann (1956, 1957, 1959). He distinguished four different antigens or groups of antigens in the egg surface. Of these one belongs to the jelly coat and may be disregarded here.
The A antigen has its seat in the egg surface and seems to be an important factor in activation. A reaction between the cellular A antigen
and its antibody brings about an activation of the nonfertilized egg (see
also, Baxandall et al., 1964a). The A antigen is a heat-stable compound
which is not attacked by trypsin ; a number of tests indicate that it is an
acid mucopolysaccharide with glucose and mannose as sugar components.
The rate of fertilization is decreased by the action of an antibody against
another heat-stable compound in the egg surface. The analysis has not
been brought as far in the case of this F antigen as in that of the A
antigen. Its carbohydrate nature seems rather probable, but it may not
be the only antigenic substance responsible for the effect on the rate of
fertilization. Beside the F antigen, the C antigen is involved in the
cortical changes. This antigen seems to be of protein nature (Perlmann,
1957).
As mentioned in Section I, Baxandall et al. (1964b) have by immunoelectron microscopical analysis demonstrated both heat-stable and heatlabile antigens, probably all three (groups of) antigens distinguished by
Perlmann, to be present in the vitelline membrane. Conversely, the reaction of the ferritin-labeled antiegg γ-globulin with the cytoplasmic surface of the egg is weak even when the vitelline membrane has been impaired by trypsin treatment. This points to the conclusion that much of
the specific interaction with spermatozoon is located in the vitelline
membrane. T. Hultin (1948a) showed that removal of the vitelline membrane by trypsin treatment considerably enhances the capacity for crossfertilization between sea urchins. Eggs of Psammechinus
microtuberculatus,
Sphaerechinus
granulans,
and Paracentrotus
lividus
were
inseminated with sperm of Psammechinus
miliaris and
Sphaerechinus
granulans. It was inferred that the principal cross-fertilization barrier
was removed with the vitelline membrane of the egg. However, no pronounced enhancement of cross fertilization was found in trypsin-treated
eggs from the aforementioned species which were inseminated with sperm
a trypsin-sensitive reception system which mediates the effective attachment of the spermatozoon. An activating system, on the other hand, is
not affected by the trypsin pretreatment. It was shown by the same
authors that treatment of the egg with neuramidase had no apparent
effect on the egg surface {loc. cit.). Earlier Runnström et al. (1943) had
shown that the fertilization was not affected by a hyaluronidase from
bull testicle (preparation by Hahn, 1943).
The distinction between a reception and an activation system is in
keeping with results obtained by Perlmann (1956, 1957, 1959). He distinguished four different antigens or groups of antigens in the egg surface. Of these one belongs to the jelly coat and may be disregarded here.
The A antigen has its seat in the egg surface and seems to be an important factor in activation. A reaction between the cellular A antigen
and its antibody brings about an activation of the nonfertilized egg (see
also, Baxandall et al., 1964a). The A antigen is a heat-stable compound
which is not attacked by trypsin ; a number of tests indicate that it is an
acid mucopolysaccharide with glucose and mannose as sugar components.
The rate of fertilization is decreased by the action of an antibody against
another heat-stable compound in the egg surface. The analysis has not
been brought as far in the case of this F antigen as in that of the A
antigen. Its carbohydrate nature seems rather probable, but it may not
be the only antigenic substance responsible for the effect on the rate of
fertilization. Beside the F antigen, the C antigen is involved in the
cortical changes. This antigen seems to be of protein nature (Perlmann,
1957).
As mentioned in Section I, Baxandall et al. (1964b) have by immunoelectron microscopical analysis demonstrated both heat-stable and heatlabile antigens, probably all three (groups of) antigens distinguished by
Perlmann, to be present in the vitelline membrane. Conversely, the reaction of the ferritin-labeled antiegg γ-globulin with the cytoplasmic surface of the egg is weak even when the vitelline membrane has been impaired by trypsin treatment. This points to the conclusion that much of
the specific interaction with spermatozoon is located in the vitelline
membrane. T. Hultin (1948a) showed that removal of the vitelline membrane by trypsin treatment considerably enhances the capacity for crossfertilization between sea urchins. Eggs of Psammechinus
microtuberculatus,
Sphaerechinus
granulans,
and Paracentrotus
lividus
were
inseminated with sperm of Psammechinus
miliaris and
Sphaerechinus
granulans. It was inferred that the principal cross-fertilization barrier
was removed with the vitelline membrane of the egg. However, no pronounced enhancement of cross fertilization was found in trypsin-treated
eggs from the aforementioned species which were inseminated with sperm