Independent Photoreceptive Circadian Clocks Throughout Drosophila - Article Example

There is ample background information on the genes that contribute to the biological clock in Drosophila. These include the period (per) and timeless (Tim) clock genes. In addition, drosophila that lacks photoreceptive organs has been observed to transmit light information to the clock (Plautz et al., 1633).  This indicates the existence of unidentified circadian photoreceptors in the insect.

Each of these three segments exhibited rhythmic bioluminescence in light-dark conditions. When the conditions were changed to constant darkness, a gradual decrease in amplitude was observed (Plautz et al., 1633). The cultures managed to restrain to a new light-dark cycle where the onset of light occurred 6 hours later than the free-running subjective dawn. The process of entrainment happened in a cycle and the main bioluminescent peak declined 20 hours after lights-on. These findings show that other organs such as the legs, wings, and testes in drosophila express photoreceptors. After reviewing the article, the following research questions can be formulated. First, the expression of per gene in the tissues displaying photoreceptive activity needs to be investigated. Secondly, a comparison needs to be made on the expression of per and Tim genes in the tissues displaying photoreceptive activity.