Advanced analysis of a cryptochrome mutation's effects on the robustness and phase of molecular cycles in isolated peripheral tissues of Drosophila.
BACKGROUND
Previously, we reported effects of the cry(b) mutation on circadian rhythms in period and timeless gene expression within isolated peripheral Drosophila tissues. We relied on luciferase activity driven by the respective regulatory genomic elements to provide real-time reporting of cycling gene expression. Subsequently, we developed a tool kit for the analysis of behavioral and molecular cycles. Here, we use these tools to analyze our earlier results as well as additional data obtained using the same experimental designs.


RESULTS
Isolated antennal pairs, heads, bodies, wings and forelegs were evaluated under light-dark cycles. In these conditions, the cry(b) mutation significantly decreases the number of rhythmic specimens in each case except the wing. Moreover, among those specimens with detectable rhythmicity, mutant rhythms are significantly weaker than cry+ controls. In addition, cry(b) alters the phase of period gene expression in these tissues. Furthermore, peak phase of luciferase-reported period and timeless expression within cry+ samples is indistinguishable in some tissues, yet significantly different in others. We also analyze rhythms produced by antennal pairs in constant conditions.


CONCLUSIONS
These analyses further show that circadian clock mechanisms in Drosophila may vary in a tissue-specific manner, including how the cry gene regulates circadian gene expression.
Levine
Joel D
JD
Department of Biology and NSF Center for Biological Timing, Brandeis University, Waltham, MA 02454, USA. jlev@brandeis.edu
Funes
Pablo
P
Dowse
Harold B
HB
Hall
Jeffrey C
JC
D024506:5' Flanking Region; D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology; D056931:Cryptochromes; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology; D017930:Genes, Reporter; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D056950:Period Circadian Proteins; D010507:Periodicity; D017440:Photoperiod; D017956:Photoreceptor Cells, Invertebrate; D043562:Receptors, G-Protein-Coupled; D013696:Temperature
D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D019476:Insect Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; C096445:tim protein, Drosophila; D008156:Luciferases