Drosophila embriyogenezinde robustluk ve plastisite: Neredeyse izogenik ve izogenik olmayan kitle popülasyonlarının karşılaştırmalı analizi

Robustness and plasticity are fundamental aspects of early development, but how they are shaped by genetic background and environment remains unclear. To address this, we examined the effect of temperature perturbation on the early embryonic markers in Drosophila melanogaster across widely used isogenic laboratory lines with potential genetic differences, natural populations from Saimbeyli/Adana, and weak bcd mutants. Early embryonic markers included the Bcd gradient and Hunchback (hb) and even-skipped (eve) stripe positions. At 25°C, most wild-type isogenic strains had comparable hb pbps on average. On the other hand, Canton S had the most variable (5.2) hb pbp %EL, whereas the Saimbeyli Mass population had the most stable, least variable (1.5) pbps at the same temperature. At 29°C, Oregon R hb pbps shifted posteriorly, while the Saimbeyli Mass line remained unchanged compared to 25oC. Canton S had the highest variation (5.05) Oregon R had the lowest variation (1.4). Eve second stripe was generally more robust against temperature change than hb, though Berlin K, Oregon R, and Saimbeyli Mass showed significant shifts towards posterior. For eve second stripe at 29oC, Saimbeyli 2 had the highest variation (2.8) and Berlin K had the lowest (0.8). In weak bcd mutant lines, steepness of Bcd gradient increased at 22°C, which correlated with the increase in embryo-to-embryo variations. They also showed lower survival rates which correlated with increased mutant cuticle phenotypes. In contrast, wild-type isogenic and Saimbeyli lines maintained high viability under all conditions. Notably, the Saimbeyli mass line showed more robust (robust averages across temperatures) but more variable (increased embryo-to-embryo variation) hb pbps, but greater variability and plasticity in eve expression. These findings indicate that robustness and plasticity are not uniform outcomes of development, but depend on the segmentation network, the developmental marker, and maternal inputs. Development can buffer some traits while allowing flexibility in others, balancing stability in response to the environmental perturbations.