title: Analysis of the circadian clock gene period in the sheep blow fly Lucilia cuprina.
abstract: We have isolated a homologue of the period (per) gene from the Australian sheep blow fly, Lucilia cuprina, as part of a comparative approach to the analysis of dipteran circadian systems. Sequence analysis of the 4 kb per cDNA revealed the conservation of three functional domains, namely the PAS dimerization motif, and the nuclear and cytoplasmic localization domains. A fourth domain, the threonine-glycine (TG) repeat region, is also conserved in L. cuprina per but has been severely truncated. No length variation was found in the TG repeat of L. cuprina or L. sericata collected from several different latitudinal zones. Expression analysis indicated a diel oscillation in per mRNA in LD 12:12 with a period of 24 h and a peak at Zt 12. PER-immunoreactive protein oscillations were also demonstrated, with peak immunoreactivity lagging approximately 3 h behind peak mRNA levels. These results show the existence of a Drosophila-like circadian system in a calliphorid fly. They also provide evidence for the conservation of per function across the Diptera, and confirm the relevance of the Drosophila system as a model for fly circadian rhythms.
authors.affiliation: School of Biological Sciences, University of Auckland, New Zealand.
authors.forename: G R
authors.initials: GR
authors.lastname: Warman
authors.forename: R D
authors.initials: RD
authors.lastname: Newcomb
authors.forename: R D
authors.initials: RD
authors.lastname: Lewis
authors.forename: C W
authors.initials: CW
authors.lastname: Evans
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids; D000818:Animals; D001483:Base Sequence; D001683:Biological Clocks; D002940:Circadian Rhythm; D018076:DNA, Complementary; D004175:Diptera / Q000235:genetics*; D029721:Drosophila Proteins; D017344:Genes, Insect; D005998:Glycine; D019476:Insect Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D056950:Period Circadian Proteins; D010802:Phylogeny; D012333:RNA, Messenger / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D012756:Sheep / Q000469:parasitology; D013912:Threonine; D013997:Time Factors
chemical_list: D000596:Amino Acids; D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D013912:Threonine; D005998:Glycine