C Y T O G E N E T I C M E C H A N I S M S I N S I L K W O R M S
253
(2) Alterations of the normal cytogenetic mechanisms of development
do not actually occur at the very beginning of development, but in the
course of morphogenesis in the integral system that has already passed
through a rather long preembryonic ontogenesis. The morphogenetic
processes of early embryogenesis in this system formed under the control of the maternal genotype do not depend on the peculiarities of the
processes of maturation and fertilization. On the contrary, the course
of these processes is itself under the control of the developing system as
a whole. No wonder that regulative mechanisms of this system correct
the course of cytogenetic deviations bringing them into the normal
channel.
(3) Different modifications of the cytogenetic processes of maturation
and amphimixis lead ultimately (although by different ways) to the same
result, i.e., to the formation of the orthoploid, genetically competent, dior polyploid cleavage nucleus whose derivatives soon come into action
in normal biosynthesis and morphogenesis.
The abundance of alterations of the ordinary developmental mechanism of egg maturation and fertilization which we meet under experimental conditions in the silkworm is very impressive indeed. It facilitates
the understanding of the resources used by an inventive nature for the
evolutionary transition from amphimictic cytogenetic mechanism to
manifold types of parthenogenesis and apomixis.
References
Astaurov, B. L. (1933). "Silkworm Breeding in Japan and Some Problems of Sericulture in the USSR," 192 pp. Selchozgiz, Moscow.
Astaurov, B. L. (1936a). Compt. Rend. Acad. Sei. URSS (N.S.) 2, 283 (Russ. and
Engl.).
Astaurov, B. L. (1936b). Bull. Lenin Acad. Agr. Sei. 12, 47 (Russ.).
Astaurov, B. L. (1937). Biol. Zh. 6, 3 (Russ., Germ. Sum.).
Astaurov, B. L. (1940). "Artificial Parthenogenesis in the Silkworm: An Experimental Study," 240 pp. Acad. Sei. USSR, Moscow (Russ., Engl. Sum.).
Astaurov, B. L. (1943). Zh. Obshch. Biol. 4, 313 (Russ., Germ. Sum.).
Astaurov, B. L. (1947a). Compt. Rend. Acad. Sei. URSS (N.S.) 58, 887 (Russ.).
Astaurov, B. L. (1947b). Zh. Obshch. Biol. 8, 421 (Russ.).
Astaurov, B. L. (1948a). Usp. Sovrem. Biol. 25, 49 (Russ.).
Astaurov, B. L. (1948b). Trav. Inst. Cytol. Histol. Embryol. Acad. Sei., URSS 3,
186 (Russ.).
Astaurov, B. L. (1948c). Dokl. Akad. Nauk SSSR 59, 1029 (Russ.).
Astaurov, B. L. (1948d). Dokl. Akad. Nauk SSSR 61, 411 (Russ.).
Astaurov, B. L. (1955). Byul. Mosk. Obshchestva Ispytatelei PHrody Otd. Biol. 60,
37 (Russ.).
Astaurov, B. L. (1956a). Usp. Sovrem. Biol. 42, 62 (Russ.).
Astaurov, B. L. (1956b). Byul. Mosk. Obshchestva Ispytatelei Prirody Otd. Biol. 61,
45 (Russ., Engl. Sum.).
Astaurov, B. L. (1957). Proc. Zool. Soc., Calcutta, Mookerjee Mem. Vol. 29-55.
253
(2) Alterations of the normal cytogenetic mechanisms of development
do not actually occur at the very beginning of development, but in the
course of morphogenesis in the integral system that has already passed
through a rather long preembryonic ontogenesis. The morphogenetic
processes of early embryogenesis in this system formed under the control of the maternal genotype do not depend on the peculiarities of the
processes of maturation and fertilization. On the contrary, the course
of these processes is itself under the control of the developing system as
a whole. No wonder that regulative mechanisms of this system correct
the course of cytogenetic deviations bringing them into the normal
channel.
(3) Different modifications of the cytogenetic processes of maturation
and amphimixis lead ultimately (although by different ways) to the same
result, i.e., to the formation of the orthoploid, genetically competent, dior polyploid cleavage nucleus whose derivatives soon come into action
in normal biosynthesis and morphogenesis.
The abundance of alterations of the ordinary developmental mechanism of egg maturation and fertilization which we meet under experimental conditions in the silkworm is very impressive indeed. It facilitates
the understanding of the resources used by an inventive nature for the
evolutionary transition from amphimictic cytogenetic mechanism to
manifold types of parthenogenesis and apomixis.
References
Astaurov, B. L. (1933). "Silkworm Breeding in Japan and Some Problems of Sericulture in the USSR," 192 pp. Selchozgiz, Moscow.
Astaurov, B. L. (1936a). Compt. Rend. Acad. Sei. URSS (N.S.) 2, 283 (Russ. and
Engl.).
Astaurov, B. L. (1936b). Bull. Lenin Acad. Agr. Sei. 12, 47 (Russ.).
Astaurov, B. L. (1937). Biol. Zh. 6, 3 (Russ., Germ. Sum.).
Astaurov, B. L. (1940). "Artificial Parthenogenesis in the Silkworm: An Experimental Study," 240 pp. Acad. Sei. USSR, Moscow (Russ., Engl. Sum.).
Astaurov, B. L. (1943). Zh. Obshch. Biol. 4, 313 (Russ., Germ. Sum.).
Astaurov, B. L. (1947a). Compt. Rend. Acad. Sei. URSS (N.S.) 58, 887 (Russ.).
Astaurov, B. L. (1947b). Zh. Obshch. Biol. 8, 421 (Russ.).
Astaurov, B. L. (1948a). Usp. Sovrem. Biol. 25, 49 (Russ.).
Astaurov, B. L. (1948b). Trav. Inst. Cytol. Histol. Embryol. Acad. Sei., URSS 3,
186 (Russ.).
Astaurov, B. L. (1948c). Dokl. Akad. Nauk SSSR 59, 1029 (Russ.).
Astaurov, B. L. (1948d). Dokl. Akad. Nauk SSSR 61, 411 (Russ.).
Astaurov, B. L. (1955). Byul. Mosk. Obshchestva Ispytatelei PHrody Otd. Biol. 60,
37 (Russ.).
Astaurov, B. L. (1956a). Usp. Sovrem. Biol. 42, 62 (Russ.).
Astaurov, B. L. (1956b). Byul. Mosk. Obshchestva Ispytatelei Prirody Otd. Biol. 61,
45 (Russ., Engl. Sum.).
Astaurov, B. L. (1957). Proc. Zool. Soc., Calcutta, Mookerjee Mem. Vol. 29-55.