Abstract:
Developmental noise in the organism is known to be associated with a change in the
pattern of the asymmetry of bilateral traits. The study focuses on the effect of sulfur
dioxide gas, a main component of smog, on the bilateral asymmetry of Drosophila
melanogaster wings when exposed during the larval stage. Three treatment groups of
fly larvae, designated as no exposure (NSE), low exposure (LSE) and high exposure
(HSE) were exposed to 0, 0.04 and 0.4 ppm of SO2, respectively. Measurement of 35
wing vein traits (based on 9 designated landmark points) was followed by the
standard protocol for the analysis of fluctuating asymmetry. Two traits in the males of
the NSE group showed asymmetry, while none was observed among the flies in the
SO2 exposed groups. The possibility of inbreeding depression and selection against
asymmetric specimens in the SO2 exposed groups is discussed..
