Temporal expression patterns of timeless in vg and cry(b) mutants of Drosophila melanogaster

The temporal expression patterns of timeless (tim) in Drosophila melanogaster at various time points were studied in intestine and salivary gland of wild type (WT), vestigial (vg) and cryptochrome-absent (cry(b)) mutants under 12 hr:12 hr white light:darkness (LD) and 12 hr:12 hr blue light (450 nm):darkness (BD) conditions. At ZT 06 and ZT 10, tim expression was almost nil and at ZT 18 and ZT 22, the expression was most pronounced in WT and mutants, when compared to other time points. As vg flies have greatly reduced wings, their gross locomotor activity was poorer and levels of tim expression were also least than WT flies. The weaker expression of tim in cry(b) flies suggested the significant role of blue light photoreceptor cryptochrome for a stronger synchronization of circadian clock. The expression patterns of tim in the salivary gland of larvae further suggested the presence of peripheral oscillators during the developmental stages.