240
B. L. ASTAUROV
and leads to the formation of four haploid female nuclei (three polar
body nuclei and a female pronucleus) besides one or several sperm
nuclei.
By means of centrifugation of freshly laid eggs at this stage of
maturation, Kawaguchi (1936a) induced different displacements of
nuclei, their fusion in irregular combinations and, as a result, the appearance of several exceptional types of progeny. Among them he obtained
some diploid individuals completely lacking paternal hereditary markers.
They have evidently arisen as a result of the elimination of sperm
nuclei and of the autogamic fusion of two haploid derivatives of the
oocyte nucleus. These exceptional individuals are therefore of parthenogenetic or more correctly, of gynogenetic origin.
The author tried to induce radiation gynogenesis (or to obtain the
so-called Hertwig's effect) by means of fertilization with the heavily
irradiated sperm as well as by the same procedure followed by subsequent thermoactivation (Astaurov, 1937). Both attempts were unsuccessful so that the matroclinous specimens obtained by Kawaguchi
(1936a), as far as the author knows, are the sole example of experimental gynogenesis in B. mori.
B. Dispermic Androgenesis
An easy way of inducing complete androgenetic (merogonial) development up to the adult stage would be a most advantageous developmental
cytogenetic alteration in silkworms, offering some opportunities for an
experimental analysis of important problems of morphogenesis. An androgenetic organism develops at the expense of the maternal cytoplasmic
and paternal nuclear material. A successful creation of such adult
"merogons" or nucleocytoplasmic hybrids (especially interspecific ones)
has been considered since the pioneer work of Boveri (1889) as an
experimentum crucis for a discrimination between the two principal
cellular components as responsible factors in morphogenesis and heredity. As far as the author knows, complete intraspecific (or homospermic)
androgenesis in animals was produced for the first time in B. mori
independently in Japan and in the USSR (Has'moto, 1929, 1934b;
Astaurov, 1936b, 1937).
Complete interspecific (or heterospermic) androgenesis in animals has
been produced for the first time also in the silkworm, in nucleocytoplasmic hybrids between B. mori L. (nucleus) and B. mandarina Moore
(cytoplasm), and vice versa (Astaurov and Ostriakova-Varshaver,
1957a-c).
When crossing homozygous males odod {od translucent larval skin,
recessive sex-linked mutation localized at 49.6 in Z chromosome) with
the normal ZW females, Haslmoto (1929) unexpectedly found among
B. L. ASTAUROV
and leads to the formation of four haploid female nuclei (three polar
body nuclei and a female pronucleus) besides one or several sperm
nuclei.
By means of centrifugation of freshly laid eggs at this stage of
maturation, Kawaguchi (1936a) induced different displacements of
nuclei, their fusion in irregular combinations and, as a result, the appearance of several exceptional types of progeny. Among them he obtained
some diploid individuals completely lacking paternal hereditary markers.
They have evidently arisen as a result of the elimination of sperm
nuclei and of the autogamic fusion of two haploid derivatives of the
oocyte nucleus. These exceptional individuals are therefore of parthenogenetic or more correctly, of gynogenetic origin.
The author tried to induce radiation gynogenesis (or to obtain the
so-called Hertwig's effect) by means of fertilization with the heavily
irradiated sperm as well as by the same procedure followed by subsequent thermoactivation (Astaurov, 1937). Both attempts were unsuccessful so that the matroclinous specimens obtained by Kawaguchi
(1936a), as far as the author knows, are the sole example of experimental gynogenesis in B. mori.
B. Dispermic Androgenesis
An easy way of inducing complete androgenetic (merogonial) development up to the adult stage would be a most advantageous developmental
cytogenetic alteration in silkworms, offering some opportunities for an
experimental analysis of important problems of morphogenesis. An androgenetic organism develops at the expense of the maternal cytoplasmic
and paternal nuclear material. A successful creation of such adult
"merogons" or nucleocytoplasmic hybrids (especially interspecific ones)
has been considered since the pioneer work of Boveri (1889) as an
experimentum crucis for a discrimination between the two principal
cellular components as responsible factors in morphogenesis and heredity. As far as the author knows, complete intraspecific (or homospermic)
androgenesis in animals was produced for the first time in B. mori
independently in Japan and in the USSR (Has'moto, 1929, 1934b;
Astaurov, 1936b, 1937).
Complete interspecific (or heterospermic) androgenesis in animals has
been produced for the first time also in the silkworm, in nucleocytoplasmic hybrids between B. mori L. (nucleus) and B. mandarina Moore
(cytoplasm), and vice versa (Astaurov and Ostriakova-Varshaver,
1957a-c).
When crossing homozygous males odod {od translucent larval skin,
recessive sex-linked mutation localized at 49.6 in Z chromosome) with
the normal ZW females, Haslmoto (1929) unexpectedly found among