QUANTITY OF FUNCTIONALLY CHANGED CELLS AS AN IDENTIFICATOR OF THE MOMENT OF THE ORGANIZMUS TRANSFER TO THE NEXT
PERIOD OF DEVELOPMENT
I. P. Shabalkin, P. I. Shabalkin
Cancer Research Center RAMS, Moscow
As "the threshold gears are peculiar to all processes which are flowing past in the world", the problem of looking
up of quantitative criterion determining transition of a biological system from one condition to another, is one of
the main problems of natural sciences. For analysis of the given problem we investigated some stages of forwardness
of marine aster Asterias rubens (mean and late blastula, early and late gastrula, early larva), distinguishing
among themselves by morphological characters. Change of structure of cell populations at each stage of development
A. rubens analyzed with the help of method of quantitative assessment of functional condition of cells genome
(Shabalkin, 1988). The method is based on cytophotometryc analysis of cell populations coloured by Feulgen
(quantifying of DNA in cell) and Naftol yellow S (quantifying of histones in a cell). As the criterion of estimation
of functional condition of the cell was used the parameter CFAGEN, coefficient of functional activity of cell genome
deduced from histone/DNA ratio after estimation of the absorbency of the nucleus coloured by two chromophores. The
data obtained showed that at the moment of organism transition from one stage of development (late blastula) to
another (early gastrula) the difference in CFAGEN values between these stages was statistically authentic. Thus
comparison of cell distribution histograms has show that cell population conforming to the early gastrula contains
33 % cells with the level of genome functional activity that differs from this one in the cell population conforming
to the late blastula. Just in the same moment, the transition of an organism from the stage of late gastrula to the
stage of larva is accompanied by statistically authentic distinction in CFAGEN between these stages and availability
of more than 1/3 cells (34 %) of the population at the larva stage showing genome functional activity different from
that at the late gastrula stage. Thus, it is established, that the biological system passes to qualitatively new
condition, if quantity of members of this system changes (increaser or decreases comparatively to a standard point
of reference: the norm, previous system status and etc.) not less than on 1/3.
Key words: stage, development, transition, blastula, gastrula, larva, DNA, histone
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