MORPHOGENETIC CONSEQUENCES OF SHORT-TERM HEAT STRESS IN SHORT- AND LONG-LIVED LINES OF THE HOUSE FLY (MUSCA DOMESTICA L.): WING GEOMETRIC MORPHOMETRY

Abstract

The morphogenetic consequences of short-term heat stress (SHS) were studied in two housefly lines that were massively selected for lifespan based on assessing the variability of the adult wing using geometric morphometry methods. Significant differences in wing size and shape were revealed between control and impact groups of different sexes in the Shg (short-lived) and Lg (long-lived) lines. The CTS effect manifested itself in an increase in the size of the wing and a directional change in its shape. The intergroup hierarchy of sex and stress-induced differences is expressed equally in both strains of flies. The range of linear differences is significantly higher than gender differences, which in turn are higher than the level of stress-induced ones. The instability of the adult wing development (Vm) of the Shg line is significantly higher than that of the Lg line, and higher in all groups of females, but in most cases significantly lower in impact groups (taking into account the increase in size, the latter may be associated with the effect of hormesis). It is hypothesized that the directed morphogenetic effects of CTS are based on hidden species-specific modifications, the appearance of which in the phenotype is caused by stress-induced epigenetic rearrangements of the genome, causing similar morphological changes in the wing in groups of males and females of adults of both lines. The phenotypic plasticity of lines during selection for different life spans and changes caused by CTC directly indicate the reality of stress-induced rapid morphogenetic rearrangements during a sharp change in environmental conditions.