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R. LALLIER
changes. The immunological properties of actomyosin are changed by
treatment with animalizing agents such as iodide and thiocyanate
(Arosio, 1953). All these changes indicate a denaturation process of the
proteins by animalizing agents. From these results Ranzi concludes that
a denaturation process is the basis of the action of animalizing agents.
As to the vegetalizing agents, they do not change the properties of
fibrillar proteins to any considerable extent. In fact they appear to exert
a protective effect against the denaturation process. Thus, lithium ions
protect proteins against changes induced by animalizing agents and the
action of urea. Further, lithium ions increase their resistance to proteolytic enzymes such as trypsin and papain (Ranzi and Citterio, 1954;
Ranzi et al., 1957). These proteolytic enzymes themselves exert
animalizing effects (Hörstadius, 1949,1953 ; Moore, 1952). The protecting
effects of lithium are also observed on isolated cell structures such as
chromosomes (Orlandi, 1953), yolk granules (Cigada, 1954) and also on
glycerinated muscle fibres (Brioschi, 1955). Ranzi (1951, 1957a) has
interpreted these phenomena in the following way. The animalizing
agents favour the demolition of the pre-existing protein structures while
the vegetalizing agents increase resistance to such demolition. The
animalizing agents, favouring the enlargement of zones of protein
demolition, would in this way induce animalization. Reciprocally, the
diminution of these zones of protein demolition under the protective
influence of the vegetalizing agents would provoke vegetalization.
According to Ranzi (1957b), the development of the egg may be
conceived in the following way. At the animal pole, the protoplasm of
the unfertilized sea urchin egg has a high reactivity. The instability of
the proteins at this pole would facilitate the processes of protein
demolition which are necessary for the synthesis of new proteins. At
fertilization, according to the conception of Runnström (1949), certain
enzymes are activated with, as a result, a rise in metabolism at the
animal pole. The activation of enzymes and the subsequent formation of
metabolites would then lead to the development of the animal pole.
The stabilization of the vegetal pole would result from failure to form
these metabolites.
Ranzi's concept is based on a very extensive study of the effects of
animalizing and vegetalizing agents. Nevertheless nothing is known
about the effects on proteins of some very active animalizing and
vegetalizing agents such as zinc ions, polysulphonic ions, phenazone and
chloramphenicol. Some, such as Germanin, are known to protect
proteins against precipitation with tannin or mercuric chloride and heat
coagulation (Collier, 1926; Jirovec and Kociân, 1930; Kociân, 1936).
However Suramine exerts a strong animalizing action on the sea urchin
eggs (Lallier, 1957a).
R. LALLIER
changes. The immunological properties of actomyosin are changed by
treatment with animalizing agents such as iodide and thiocyanate
(Arosio, 1953). All these changes indicate a denaturation process of the
proteins by animalizing agents. From these results Ranzi concludes that
a denaturation process is the basis of the action of animalizing agents.
As to the vegetalizing agents, they do not change the properties of
fibrillar proteins to any considerable extent. In fact they appear to exert
a protective effect against the denaturation process. Thus, lithium ions
protect proteins against changes induced by animalizing agents and the
action of urea. Further, lithium ions increase their resistance to proteolytic enzymes such as trypsin and papain (Ranzi and Citterio, 1954;
Ranzi et al., 1957). These proteolytic enzymes themselves exert
animalizing effects (Hörstadius, 1949,1953 ; Moore, 1952). The protecting
effects of lithium are also observed on isolated cell structures such as
chromosomes (Orlandi, 1953), yolk granules (Cigada, 1954) and also on
glycerinated muscle fibres (Brioschi, 1955). Ranzi (1951, 1957a) has
interpreted these phenomena in the following way. The animalizing
agents favour the demolition of the pre-existing protein structures while
the vegetalizing agents increase resistance to such demolition. The
animalizing agents, favouring the enlargement of zones of protein
demolition, would in this way induce animalization. Reciprocally, the
diminution of these zones of protein demolition under the protective
influence of the vegetalizing agents would provoke vegetalization.
According to Ranzi (1957b), the development of the egg may be
conceived in the following way. At the animal pole, the protoplasm of
the unfertilized sea urchin egg has a high reactivity. The instability of
the proteins at this pole would facilitate the processes of protein
demolition which are necessary for the synthesis of new proteins. At
fertilization, according to the conception of Runnström (1949), certain
enzymes are activated with, as a result, a rise in metabolism at the
animal pole. The activation of enzymes and the subsequent formation of
metabolites would then lead to the development of the animal pole.
The stabilization of the vegetal pole would result from failure to form
these metabolites.
Ranzi's concept is based on a very extensive study of the effects of
animalizing and vegetalizing agents. Nevertheless nothing is known
about the effects on proteins of some very active animalizing and
vegetalizing agents such as zinc ions, polysulphonic ions, phenazone and
chloramphenicol. Some, such as Germanin, are known to protect
proteins against precipitation with tannin or mercuric chloride and heat
coagulation (Collier, 1926; Jirovec and Kociân, 1930; Kociân, 1936).
However Suramine exerts a strong animalizing action on the sea urchin
eggs (Lallier, 1957a).