ιββ
SAUL WISCHNITZER
microscope to study sea urchin ova, found evidence suggesting that multiplication occurs by a transverse division of the stacks of lamellae. The possibility that the Golgi complex may arise either de novo or from other existing cytoplasmic organelles, however, cannot be excluded.
Conflicting evidence exists regarding the function of the Golgi complex
in amphibian ova. Balinsky and Devis (1963) claim that some of the small
vesicles of these organelles are responsible for the formation of cortical
granules (see p. 162). This may be the case in anurans, but in urodeles,
where cortical granules are lacking, the function of the Golgi complex
must differ. Wartenberg (1962) suggests that the cisternae serve as a source
of vesicles which arise by pinching off. These vesicles are then thought to
participate indirectly in the process of yolk formation (see p. 171).
The function of the Golgi apparatus has recently been studied in mammalian somatic cells, particularly in the pancreas, by the application of
autoradiographic techniques to electron microscopy (Caro and Palade,
1964). This study suggests that the Golgi complex is probably not involved
in synthesis, but rather is a site of condensation of material formed elsewhere. It would be desirable to apply this approach to amphibian oocytes
and, thereby, determine if a parallel functional activity exists.
In amphibian eggs, the annulate lamellae have been observed as a
complex membranous system in Xcncpns (Balinsky and Devis, 1963) and
Necturus (Kessel, 1963), and as individual sheets in Triturus (Wischnitzer,
1960). This organelle may also be present in other genera as individual
sheets which thus far have been overlooked.
The functional significance of these lamellae is not yet definitely known.
Porter (1961) has noted that this organelle is seen in either embryonic or
fetal tissues, both of which are undergoing rapid differentiation. Thus, it
has been suggested that annulate lamellae are transient structures having
a limited usefulness during the life history of the cell.
Swift (1956) originally suggested that the lamellae are involved in the
transfer of genetic specificities from the nucleus to the cytoplasm—a view
that is supported by Ruthmann (1958). On the other hand, some investigators have found an intimate association, in certain cells, between the
annulate lamellae and the ergastoplasm (Ruthmann, 1958; Rebhun, 1961;
Ross, 1962). This finding is in harmony with the observation by Merriam
(1962) and Balinsky and Devis (1963) that fine (smaller-than-ribosomal)
particles are associated with the membranous sheets. The later investigators feel, however, that the annulate lamellae function to produce the
masses of cytoplasmic vesicles which are scattered freely throughout the
cytoplasm of young oocytes and are found in large clusters in the cortical
cytoplasm of older oocytes.
Recent evidence by Chambers and Weiser (1964), Hruban et al. (1965),
SAUL WISCHNITZER
microscope to study sea urchin ova, found evidence suggesting that multiplication occurs by a transverse division of the stacks of lamellae. The possibility that the Golgi complex may arise either de novo or from other existing cytoplasmic organelles, however, cannot be excluded.
Conflicting evidence exists regarding the function of the Golgi complex
in amphibian ova. Balinsky and Devis (1963) claim that some of the small
vesicles of these organelles are responsible for the formation of cortical
granules (see p. 162). This may be the case in anurans, but in urodeles,
where cortical granules are lacking, the function of the Golgi complex
must differ. Wartenberg (1962) suggests that the cisternae serve as a source
of vesicles which arise by pinching off. These vesicles are then thought to
participate indirectly in the process of yolk formation (see p. 171).
The function of the Golgi apparatus has recently been studied in mammalian somatic cells, particularly in the pancreas, by the application of
autoradiographic techniques to electron microscopy (Caro and Palade,
1964). This study suggests that the Golgi complex is probably not involved
in synthesis, but rather is a site of condensation of material formed elsewhere. It would be desirable to apply this approach to amphibian oocytes
and, thereby, determine if a parallel functional activity exists.
In amphibian eggs, the annulate lamellae have been observed as a
complex membranous system in Xcncpns (Balinsky and Devis, 1963) and
Necturus (Kessel, 1963), and as individual sheets in Triturus (Wischnitzer,
1960). This organelle may also be present in other genera as individual
sheets which thus far have been overlooked.
The functional significance of these lamellae is not yet definitely known.
Porter (1961) has noted that this organelle is seen in either embryonic or
fetal tissues, both of which are undergoing rapid differentiation. Thus, it
has been suggested that annulate lamellae are transient structures having
a limited usefulness during the life history of the cell.
Swift (1956) originally suggested that the lamellae are involved in the
transfer of genetic specificities from the nucleus to the cytoplasm—a view
that is supported by Ruthmann (1958). On the other hand, some investigators have found an intimate association, in certain cells, between the
annulate lamellae and the ergastoplasm (Ruthmann, 1958; Rebhun, 1961;
Ross, 1962). This finding is in harmony with the observation by Merriam
(1962) and Balinsky and Devis (1963) that fine (smaller-than-ribosomal)
particles are associated with the membranous sheets. The later investigators feel, however, that the annulate lamellae function to produce the
masses of cytoplasmic vesicles which are scattered freely throughout the
cytoplasm of young oocytes and are found in large clusters in the cortical
cytoplasm of older oocytes.
Recent evidence by Chambers and Weiser (1964), Hruban et al. (1965),