title: Circadian rhythm gene regulation in the housefly Musca domestica.
abstract: The circadian mechanism appears remarkably conserved between Drosophila and mammals, with basic underlying negative and positive feedback loops, cycling gene products, and temporally regulated nuclear transport involving a few key proteins. One of these negative regulators is PERIOD, which in Drosophila shows very similar temporal and spatial regulation to TIMELESS. Surprisingly, we observe that in the housefly, Musca domestica, PER does not cycle in Western blots of head extracts, in contrast to the TIM protein. Furthermore, immunocytochemical (ICC) localization using enzymatic staining procedures reveals that PER is not localized to the nucleus of any neurons within the brain at any circadian time, as recently observed for several nondipteran insects. However, with confocal analysis, immunofluorescence reveals a very different picture and provides an initial comparison of PER/TIM-containing cells in Musca and Drosophila, which shows some significant differences, but many similarities. Thus, even in closely related Diptera, there is considerable evolutionary flexibility in the number and spatial organization of clock cells and, indeed, in the expression patterns of clock products in these cells, although the underlying framework is similar.
authors.affiliation: Department of Genetics, University of Leicester, Leicester LE1 7RH, United Kingdom.
authors.forename: Veryan
authors.initials: V
authors.lastname: Codd
authors.forename: David
authors.initials: D
authors.lastname: Dolezel
authors.forename: Jan
authors.initials: J
authors.lastname: Stehlik
authors.forename: Alberto
authors.initials: A
authors.lastname: Piccin
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Garner
authors.forename: Seth N
authors.initials: SN
authors.lastname: Racey
authors.forename: Kornelis R
authors.initials: KR
authors.lastname: Straatman
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Louis
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Costa
authors.forename: Ivo
authors.initials: I
authors.lastname: Sauman
authors.forename: Charalambos P
authors.initials: CP
authors.lastname: Kyriacou
authors.forename: Ezio
authors.initials: E
authors.lastname: Rosato
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002940:Circadian Rhythm / Q000235:genetics* / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D004330:Drosophila / Q000033:anatomy & histology / Q000235:genetics / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology; D005786:Gene Expression Regulation; D017344:Genes, Insect; D006793:Houseflies / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology*; D017403:In Situ Hybridization; D009043:Motor Activity; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology; D056950:Period Circadian Proteins; D017440:Photoperiod; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D029721:Drosophila Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins; D012333:RNA, Messenger; C096445:tim protein, Drosophila