Working on basic gene structures in the ’50s, Siddiqi discovered suppressors of‘nonsense’ mutations which otherwise terminate the continuity of proteins in thecell. Hand-picked by the late Homi Bhabha to set up the molecular biology department inTIFR in 1962, Siddiqi’s second phase of work took him into the intricacies of howbehaviour in organisms is affected by genetic mutation. Experimenting on the drosophila fly with temperature-sensitive, conditional mutations—mutations whose effects are seenonly when the temperature is raised—occupied over two decades. This has, since then,grown to be a vast research field. Along with his associates, Siddiqi has identified about20 genes so far whose mutations block olfactory and gustatory responses in the drosophila.These discoveries provide a substantial lead to understanding similar mechanisms in humanbeings.
His work he describes as grappling with "large, unsolved general ideas",claiming to lose interest "when it becomes a matter of details". As if to proveit, this unassuming doubter mentions his latest area of interest: DNA archeology or studyof archaic bones.
