DYNAMICS OF MACROMOLECULAR POPULATIONS - MATHEMATICAL-MODEL OF THE QUANTITATIVE CHANGES OF RNA IN THE SILKGLAND DURING THE LAST LARVAL INSTAR

The quantitative changes of RNA in the silkgland of Bombyx mori have been studied during the last larval instar by using a mathematical model (Volterra-Kostizin model). This model can be associated with a global mechanism including synthesis and degradative processes. The numerical and statistical methods used for model analysis are described in an appendix. Thus we have compared the accumulation of total RNA (essentially ribosomal) after a treatment (juvenile hormone) and between several strains. The importance of the degradative factor is denoted to explain the observed differences, whereas the synthesis rates remain relatively stable. The last observation may lead us to an interpretation of the molecular effect of a selection to increase silk production: rather than an increase of the productivity of cellular machinery, the degradative process has been limited. © 1979 Masson, Paris.