ISSN 1062-3604, Russian Journal of Developmental Biology, 2006, Vol. 37, No. 6, pp. 401–402. © Pleiades Publishing, Inc., 2006.
Original Russian Text © N.D. Ozernyuk, 2006, published in Ontogenez, 2006, Vol. 37, No. 6, pp. 478–480.
Alexander I. Zotin was an outstanding scientist, spe-
cialist in the ﬁeld of experimental embryology and
developmental biophysics and bioenergetics. He is well
known by his studies of the water metabolism in
embryos of lower vertebrates, mechanisms of cytokine-
sis, growth equations for animals, bioenergetics of
developmental processes, and evolutionary bioenerget-
ics. However, he made his greatest contribution to the
development of contemporary biological thermody-
namics, a new discipline at the turn of physics, chemis-
try, and biology.
Zotin was born in Bodaibo, Irkutsk district, on
March 9, 1926. He entered the biological Faculty of the
Moscow State University in 1945. Here, he took a fancy
to work carried out at Department of Developmental
Dynamics under the guidance of Prof. M.M. Zava-
dovsky and planned to study at this Department. He got
acquainted with T.A. Dettlaff, who exerted a great
inﬂuence on the development of his scientiﬁc views.
Dettlaff introduced him to the traditions of the Russian
school of experimental embryologists founded by
D.P. Filatov. Zotin will stress the importance of Det-
laff’s lessons during the entire course of his life. Note
that the student’s plans for specialization at the Depart-
ment Developmental Dynamics could not be realized.
In 1948, after the August session of the All-Union
Academy of Agricultural Sciences, much changed in
biology and, speciﬁcally, at the Biological Faculty. As
a result, Zotin graduated from the Moscow State Uni-
versity in 1950 at the Department of Darwinism.
In 1950, Zotin entered the postgraduate school at the
Severtsov Institute of Animal Morphology, USSR
Academy of Sciences. His candidate thesis was related
to investigation of the properties of egg membranes in
sturgeon and salmonid ﬁshes and was a continuation of
his student’s work. As a result of these and later studies,
he discovered the enzyme of membrane hardening in
teleostean eggs and hatching enzyme in sturgeon ﬁsh.
In 1954 Zotin defended his candidate thesis “Structure,
Properties, and Signiﬁcance of Egg Membranes in
Sturgeon and Salmonid Fishes” under the guidance of
Dettlaff and S.G. Kryzhanovsky at the Zoological Insti-
tute, USSR Academy of Sciences, in Leningrad.
After a short period of work at the Presidium of the
USSR Academy of Sciences, Zotin returned to the
Institute of Animal Morphology as a senior research
worker. He took a great interest in the problems of bio-
physics already as a student but the conditions of that
time did not allow him to realize his aspirations. At the
Institute of Animal Morphology, Zotin continued his
work on water metabolism in ﬁsh and amphibian
embryos. Water metabolism in embryogenesis is
related to the formation of various watery cavities,
water entry or exit under osmotically unfavorable con-
ditions, and water renewal in the embryos. He devel-
oped several new methods and proposed mathematical
approaches for analysis of the obtained data. The
results of these studies were summarized in the mono-
graph (Zotin, 1961), which was defended as a doctoral
In 1962, Zotin began a new stage in his research
work related to the mechanisms of animal egg cleavage.
Note that Zotin was one of the ﬁrst in this country to
describe the presence of microﬁlaments in the surface
layer of eggs. In 1971, he published an original theory
of cytokinesis based on the hypothesis concerning the
mechanism of appearance and inductive properties of
the diastema, a structure arising in the spindle center
To the 80th Birthday of Alexander I. Zotin