title: Cell cycle arrest as a hallmark of insect diapause: changes in gene transcription during diapause induction in the drosophilid fly, Chymomyza costata.
abstract: The division cycle of CNS cells was arrested in G0/G1 (86.6%) and G2 (12.8%) phases in diapausing larvae of Chymomyza costata. A two-step response was observed when the diapause was induced by transferring the 3rd instar larvae from long-day to short-day conditions: first, the proportion of G2-arrested cells increased rapidly within a single day after transfer; and second, the increase of G0/G1-arrested cells started with a delay of 5 days after transfer. The changes of relative mRNA levels of seven different genes, which code for important cell cycle regulatory factors [Cyclins D and E, kinases Wee1 and Myt1, phosphatase Cdc25 (String), Dacapo (p27), and PCNA] were followed using qRT-PCR technique. Two reference genes (Rp49 and ss-tubulin) served as a background. Significant transcriptional responses to photoperiodic transfer were observed for two genes: while the relative levels of dacapo mRNA increased during the rapid entry into the G2 arrest, the pcna expression was significantly downregulated during the delayed onset of G0/G1 arrest. In addition, moderate transcriptional upregulations of the genes coding for two inhibitory kinases, wee1 and myt1 accompanied the entry into diapause. The other genes were expressed equally in all photoperiodic conditions.
authors.affiliation: Biology Centre ASCR, Institute of Entomology, 370 05 Ceské Budejovice, Czech Republic. kostal@entu.cas.cz
authors.forename: Vladimír
authors.initials: V
authors.lastname: Kostál
authors.forename: Petra
authors.initials: P
authors.lastname: Simůnková
authors.forename: Alena
authors.initials: A
authors.lastname: Kobelková
authors.forename: Kimio
authors.initials: K
authors.lastname: Shimada
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000502:physiology*; D002490:Central Nervous System / Q000166:cytology; D003001:Cloning, Molecular; D018428:Drosophilidae / Q000166:cytology* / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva / Q000166:cytology / Q000502:physiology; D008018:Life Cycle Stages; D017440:Photoperiod; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D019476:Insect Proteins