A Study on Damage of Chromosomes Activity in Seedlings of Crepis Capillaris - Progress in Organic and Physical Chemistry: Structures and Mechanisms - page 273

16,000 nuclei. After treatment of the seeds the number of metaphases in the seedlings
over the same period (2-10 hr) was lower and depended on the concentration of phos-
phemid. At a high concentration of 1 × 10 -2 M at an average around 16,000 nuclei was
0.73% of metaphases, with preparation concentration 5 × 10 -3 M 0.82% of metaphases
around 26,500 nuclei, at a concentration of 5 × 10 -4 M observed 1.42% of metaphases
around 21,000 nuclei. However, by 20 hr after the start of treatment increased the
frequency of mitoses both in control 3.40%, and in the experience at concentration of
phosphemid 5 × 10 -3 M 2.38%. These data also reÀ ect the decline of mitotic activity
with the increase of concentration of phosphemid and her increasing with reduction of
concentration of preparation.
Mutagen may be remains in the seeds in conjunction with other cellular proteins,
by that braking advancement of phases of mitotic cycle, thus inÀ uencing on the chro-
mosomes longer and therefore stronger is damaged the synthesis of larger number of
loci of chromosomes.
In the 1960-1970s, outstanding scientists N. N. Sokolov, B. N. Sidorov [19-21]
a series of studies on effects of ethyleneimine on seedlings Cr. capillaris .
They cultivated seedlings in a solution of colchicine for ¿ ve cell generations. They
found in tetraploid and higher polyploidy cells rearrangements of chromatid type “not
—– ” under inÀ uence of colchicine.
The authors explain this phenomenon is the fact that the mutagen is saved in the
cells and there new rearrangements. [20] Seedlings were treating of ethylenei-
mine: these seedlings were washed in running water within 2 hr. From these through
48 hr were preparing “thin gruel”. Intact seedlings of Cr. capillaris were treating by
that thin gruel. In these seedlings treated by thin gruel were appearing rearrangements
of chromatid type.
The authors suggested that ethyleneimine formed active secondary mutagens,
connecting with the components of the cell, including with nucleic acids. [21], the
author's in vitro added ethyleneimine to amino acids: glycine and histidine, to the
hexamine (hexamethylenetetramine), to vitamins: thiamin (vitamin B 1 ), nicotinic acid.
Consequent treatment of seedlings of these preparations did not cause aberra-
tions. The frequency of them was at the level of control. Ethyleneimine (concentration
0.05%) caused about 15% of rearrangements, while in mixture with thiamine caused
signi¿ cantly more rearrangements (+22.27%). Treatment by ethyleneimine in mixture
with nicotinic acid, glycine, and histidine showed even some protective effect. Treat-
ment by ethyleneimine together with adenine, guanine (derivative of purine), cytosine
(derivative of pyrimidine) showed absence of effect or a small excess of rearrange-
ments above the level of rearrangements of pure ethyleneimine.
The received signi¿ cant excess frequency of rearrangements under the inÀ u-
ence of mixtures: uracil + ethyleneimine gave an increase nearly 19%, thymine
+ ethyleneimine caused nearly 61% of rearrangements (+37.25%). Guanine and
cytosine in a mixture with ethyleneimine gave an insigni¿ cant action. In the mix-
ture with thio-TEPA (three ethyleneimine groups), only thiamine gave signi¿ cant
excess frequency of rearrangements (+25.97%) over control (ethyleneimine). Af-
ter treatment of seedlings by a mixture of ethyleneimine with thymine, the excess