THE PROTEINS IN E M B R Y O N I C A N D
L A R V A L DEVELOPMENT
SILVIO RANZI
Zoology Department, State University, Milan, Italy
I. Introduction
211
II. Studies on Differentiation
211
A. Sea Urchins
212
B. Amphibians
219
C. Attempt at Comparison
225
III. Studies on Determination
227
A. Alterations in Early Determination
227
B. Differences in Proteins from Embryos showing Different Malformations
231
C. Animalizing Agents Denaturing Proteins
238
D. Protein Denaturation and Developmental Processes
239
E. Action of Vegetalizing Agents
241
F. Differences in Resistance to Breakdown of Proteins from Embryos showing
Different Malformations
244
G. Predisposition to and Inhibition of Protoplasmic Structural Breakdown
248
H. Embryonic Proteins and the Nature of the Denaturation Induced by
Animalizing Agents
249
I. Evidence from the Research of Other Authors
251
J. Conclusion
253
References
255
I. Introduction
One of the most important problems of development concerns the
changes which the proteins undergo. This problem has been under
investigation during the last sixteen years in the Department of
Zoology of Milan. In our earlier investigations we studied the problem
of determination, and more recently we considered the phenomena
which occur during embryonic differentiation.
II. Studies on Differentiation
We have studied protein differentiation by three different methods:
the salting-out method of Derrien et al. (1952), the salting-in method of
Taylor (1953), and the immunological method. With these methods we
have investigated several animals and particularly the sea urchin
Arbacia lixula L. (Ranzi and Citterio, 1956), the frog Rana esculenta L.
(Ranzi and Citterio, 1955a, b), and the toads Bufo bufo L., and B. viridis
211