ABSTRACT
Circadian rhythms are generated by endogenous circadian clocks, organized in central and peripheral clocks. An antennal peripheral clock has been demonstrated to be necessary and sufficient to generate Drosophila olfactory rhythms in response to food odours. As moth pheromonal communication has been demonstrated to follow daily rhythms, we thus investigated the occurence of a putative antennal clock in the noctuid Mamestra brassicae. From moth antennae, we isolated two full-length cDNAs encoding clock genes, period and cryptochrome, which appeared to be expressed throughout the body. In the antennae, expression of both transcripts was restricted to cells that likely represent olfactory sensory neurones. Our results suggest the occurence of a putative antennal clock that could participate in the pheromonal communication rhythms observed in vivo.
Subject(s)
Circadian Rhythm/genetics , Flavoproteins/genetics , Moths/physiology , Nuclear Proteins/genetics , Amino Acid Sequence , Animals , Cloning, Molecular , Cryptochromes , Drosophila Proteins , Female , Gene Expression , Genes, Insect , Male , Molecular Sequence Data , Moths/genetics , Olfactory Receptor Neurons/physiology , Period Circadian Proteins , Pheromones , Sequence Alignment , Sequence Analysis, DNA , Smell/physiologyABSTRACT
Using the IAL-PID2 cell line established from pupally committed imaginal wing discs of Plodia interpunctella, we have investigated the dynamics of cellular and molecular events involved in the G2/M arrest. We have first cloned a cDNA sequence named PIUSP-2 that likely encodes a homologue of the Ultraspiracle-2 isoform of Manduca sexta. When the IAL-PID2 cells were exposed to a 8 h 20E treatment applied at different times of the cell cycle, an optimal period of sensitivity of cells to 20E, in inducing G2 arrest, was determined at the S/G2 transition. Using cDNA probes specifically designed from Plodia B cyclin (PcycB), ecdysone receptor B1-isoform (PIEcR-B1) and HR3 transcription factor (PHR3), we provide evidence that the 20E-induced G2 arrest was correlated to a high induction of PHR3, PIEcR-B1, PIUSP-2 mRNAs at the S/G2 transition and a decrease in PcycB mRNA level at the end of G2 phase.
Subject(s)
G2 Phase/genetics , Gene Expression Regulation, Developmental/drug effects , Moths/genetics , RNA, Messenger/metabolism , Wings, Animal/metabolism , Amino Acid Sequence , Animals , Anisomycin/pharmacology , Base Sequence , Blotting, Northern , Cell Line , Cyclin B/metabolism , DNA Primers , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Dose-Response Relationship, Drug , Drosophila Proteins , Ecdysterone/pharmacology , Gene Expression Profiling , Molecular Sequence Data , Moths/metabolism , Random Amplified Polymorphic DNA Technique , Receptors, Steroid/metabolism , Sequence Analysis, DNA , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
Ten edentulous patients who were wearing complete dentures that appeared to be well-fitting clinically but were not satisfactory to the patient, were imaged with the use of direct coronal computed tomography. Sections were selected to pass through the maxillary first molar region to study the relationships between the maxillary denture and the supporting tissues, at rest, in maximal intercuspation, and during simulated function. The radiation dose was minimized by limiting the number of cuts made to seven through the same site in different jaw positions both with and without function. Computed tomography offers useful diagnostic information when evaluating patients who have persistently unresoluable denture problems.
