Project description:Gene expression of two populations was compared at a daylength intermediate to the two population critical photoperiods after 0 and 6 days. Genes with interaction terms are candidates for involvement in long-day response. The mosquito Wyeomyia smithii overwinters in a larval diapause that is initiated, maintained and terminated by day length (photoperiod). We use a forward genetic approach to investigate covert transcriptional events involved in the termination of diapause following exposure to long-days. We incorporate a novel approach that compares two populations (DB - southern, DR - northern) that differentially respond to a single day length. After six long days, 50% of individuals of population DB have terminated diapause and are irrevocably committed to development, though no phenotyping differences are observed. We can compare gene expression between these two populations after six long days and zero long days. The zero long day treatment will control for evolved differences between the populations and the 6 long day treatment allows for the identification of genes that are differentially expressed due to different responses to a single daylength. We identify 30 transcripts associated with differential response to day length. All of the corresponding genes with a previously annotated function are consistent with a role in the termination of diapause, with downstream developmental events, or with the transition from potentially oxygen-poor to oxygen-rich environments; none appears to be specifically part of the photoperiodic switch mechanism itself. However, among 10 unannotated genes, a gene homologous to Drosophila melanogaster CG13043 emerges from three separate forward genetic screens as a leading candidate for a gene contributing to the photoperiodic timing mechanism itself (photoperiodic switch). We name this gene photoperiodic response gene 1 (prg1). Prg1 is up-regulated under long-day response conditions, is located under a QTL for critical photoperiod and is associated with critical photoperiod after 25 generations of recombination from a cross between extreme phenotypes. Three independent forward genetic approaches identify prg1 as a gene either involved in the photoperiodic switch mechanism or very tightly linked to a gene that is. We conclude that continued forward genetic approaches will be central to understanding not only the molecular basis of photoperiodism and diapause, but also the evolutionary potential of temperate and polar animal populations when confronted with rapid climate change.
Project description:Gene expression of two populations was compared at a daylength intermediate to the two population critical photoperiods after 0 and 6 days. Genes with interaction terms are candidates for involvement in long-day response. The mosquito Wyeomyia smithii overwinters in a larval diapause that is initiated, maintained and terminated by day length (photoperiod). We use a forward genetic approach to investigate covert transcriptional events involved in the termination of diapause following exposure to long-days. We incorporate a novel approach that compares two populations (DB - southern, DR - northern) that differentially respond to a single day length. After six long days, 50% of individuals of population DB have terminated diapause and are irrevocably committed to development, though no phenotyping differences are observed. We can compare gene expression between these two populations after six long days and zero long days. The zero long day treatment will control for evolved differences between the populations and the 6 long day treatment allows for the identification of genes that are differentially expressed due to different responses to a single daylength. We identify 30 transcripts associated with differential response to day length. All of the corresponding genes with a previously annotated function are consistent with a role in the termination of diapause, with downstream developmental events, or with the transition from potentially oxygen-poor to oxygen-rich environments; none appears to be specifically part of the photoperiodic switch mechanism itself. However, among 10 unannotated genes, a gene homologous to Drosophila melanogaster CG13043 emerges from three separate forward genetic screens as a leading candidate for a gene contributing to the photoperiodic timing mechanism itself (photoperiodic switch). We name this gene photoperiodic response gene 1 (prg1). Prg1 is up-regulated under long-day response conditions, is located under a QTL for critical photoperiod and is associated with critical photoperiod after 25 generations of recombination from a cross between extreme phenotypes. Three independent forward genetic approaches identify prg1 as a gene either involved in the photoperiodic switch mechanism or very tightly linked to a gene that is. We conclude that continued forward genetic approaches will be central to understanding not only the molecular basis of photoperiodism and diapause, but also the evolutionary potential of temperate and polar animal populations when confronted with rapid climate change. 4 treatments, (Population DR, Day 0; Population DB, Day 0; Population DR, Day 6, Population DB, Day6), one dye swap (treatment Cy3 or Cy5, each replicated three times for a total of 24 arrays
Project description:This study measured the differential expression of genes from two populations of Wyeomyia smithii in the USA : KC in Maine and PB in New Jersey. The study reveals differential gene expression (DGE) in diapausing and developing larvae using microarrays. It identified the temporal and developmental pattern of DGE by showing the combined differential effects of length of day and time of day overlaid in a single plot illustrating DGE from two separate, comparative arrays. The study identified select hormonal and cell-signaling pathways underlying this pattern. This GEO record is for a full factorial comparison (1) between the two larval populations (KC, PB) and (2) reared under two photoperiods (SD, LD) for 13-14 days (Short-Day diapausing larvae L:D = 11:13 hours; Long-Day developing larvae L:D = 14.5:9.5 hours) and (3) sampled either during the day at 10-11h after lights on (ZT10) or at night 22-23h after lights-on (ZT22).
Project description:This SuperSeries is composed of the following subset Series: GSE25408: The pan-genome of the dominant human gut-associated archaeon, Methanobrevibacter smithii GSE25535: Expression data from an in vitro growth of Methanobrevibacter smithii PS Refer to individual Series