Journal of Applied and Natural Science 3(1):38-50(2011)
Photoperiod-induced clock-shifting in the circadian protein and amino acid rhythms in the larval fat body of silkworm, Bombyx mori
B. Sailaja and S. Sivaprasad*
Department of Zoology, Smt.N.P.S.GovernmentCollege for Women, Chittoor-517 002 (A.P), INDIA
*Corresponding author. E-mail: email@example.com
Abstract : The photoperiod-induced clock-shifting in the free running time of the circadian protein and amino acid rhythms was studied in the larval fat body of Bombyx mori. The analysis of peaks and troughs of phase response curves of the rhythm revealed that the fourth and fifth instar larvae grown under normal 12 h light and 12 h dark cycle (LD) showed 7 protein synthetic cycles, while those reared under continuous light (LL) recorded 9.5 cycles in fourth instar and 8 in fifth instar. Under continuous dark (DD), the protein rhythm maintained 8 cycles in fourth instar and 7.5 cycles in fifth instar. Clearly, both LL and DD conditions advance the 24-h free running time of the protein rhythm by durations ranging from 1.6 to 6.5 h. Comparative analysis of protein and amino acid rhythms shows that the photoperiod modulates the free running time of the former by altering the rate of amino acid mobilization.
Keywords : Bombyx mori , Circadian amino acid rhythm, Circadian protein rhythm, Fat body, Photoperiod