Project description:Falster is a Danish perennial ryegrass ecotype with strong vernalization requirement, while Veyo is an Italian variety with no requirement for vernalization in order to flower. The transcriptome of these two perennial ryegrass genotypes with contrasting vernalization requirements was studied during primary (vernalization and short day conditions), and secondary induction (higher temperature and long day conditions) using an RNA-Seq approach, in order to reveal transcripts with expression profiles indicative of a role in floral induction, both in the promotion and repression of flowering.
Project description:To investigate the evolution of cold response in Pooideae, five species spanning early to later diverging lineages were sampled before and after subjecting them to a drop in temperature (17C to 6C), shorter days (12 to 8 hours of light) and less intensive light. Short-term response was sampled in the afternoon 8 hours after drop in temperature but 24 hours after the respective control sample to control for diurnal rhythm. Long-term response was sampled after 4 and 9 weeks in the morning directly after lights were turned on with a respective control sample also taken in the morning on the day before the temperature drop.
Project description:Various physiological processes and behaviours are controlled by changing daylength. To dissect genes involved in the photoperiodic changes in physiology and behaviour, global expression analysis was performed using quail kept under short and long day conditions. Keywords: time course
Project description:Various physiological processes and behaviours are controlled by changing daylength. To dissect genes involved in the photoperiodic changes in physiology and behaviour, global expression analysis was performed using quail kept under short and long day conditions. Experiment Overall Design: The mediobasal hypothalamus (MBH) of quail kept under short day condition (6h light:18h dark) or long day condition (20h light:4h dark) were collected for RNA extraction. Pooled total RNA from three MBHs was labelled and hybridized on Affymetrix microarrays. Samples were collected from 6 birds every 4h during a 24 h cycle and were analyzed in duplicate set of array (two biological replicates).
Project description:Living organisms detect seasonal changes in day length (photoperiod), and alter their physiological functions accordingly, to fit seasonal environmental changes. This photoperiodic system is implicated in seasonal affective disorders and the season-associated symptoms observed in bipolar disease and schizophrenia. Thyroid-stimulating hormone beta subunit (Tshb), induced in the pars tuberalis (PT), plays a key role in the pathway that regulates animal photoperiodism. However, the upstream inducers of Tshb expression remain unknown. Here we show that late-night light stimulation acutely triggers the Eya3-Six1 pathway, which directly induces Tshb expression. Using melatonin-proficient CBA/N mice, which preserve the photoperiodic Tshb-expression response, we performed a genome-wide expression analysis of the PT under chronic short-day and long-day conditions. These data comprehensively identified long-day and short-day genes, and indicated that late-night light stimulation induces long-day genes. We verified this by advancing and extending the light period by 8 hours, which acutely induced Tshb expression, within one day. In a genome-wide expression analysis under this condition, we searched for candidate upstream genes by looking for expression that preceded Tshb’s, and identified Eya3 gene. These results elucidate the comprehensive transcriptional photoperiodic response in the PT, revealing the complex regulation of Tshb expression and unexpectedly rapid response to light changes in the mammalian photoperiodic system.
Project description:Living organisms detect seasonal changes in day length (photoperiod), and alter their physiological functions accordingly, to fit seasonal environmental changes. This photoperiodic system is implicated in seasonal affective disorders and the season-associated symptoms observed in bipolar disease and schizophrenia. Thyroid-stimulating hormone beta subunit (Tshb), induced in the pars tuberalis (PT), plays a key role in the pathway that regulates animal photoperiodism. However, the upstream inducers of Tshb expression remain unknown. Here we show that late-night light stimulation acutely triggers the Eya3-Six1 pathway, which directly induces Tshb expression. Using melatonin-proficient CBA/N mice, which preserve the photoperiodic Tshb-expression response, we performed a genome-wide expression analysis of the PT under chronic short-day and long-day conditions. These data comprehensively identified long-day and short-day genes, and indicated that late-night light stimulation induces long-day genes. We verified this by advancing and extending the light period by 8 hours, which acutely induced Tshb expression, within one day. In a genome-wide expression analysis under this condition, we searched for candidate upstream genes by looking for expression that preceded Tshb’s, and identified Eya3 gene. These results elucidate the comprehensive transcriptional photoperiodic response in the PT, revealing the complex regulation of Tshb expression and unexpectedly rapid response to light changes in the mammalian photoperiodic system. Mice were separated into 2 groups. One group was maintained under the short-day conditions (light: dark = 8 h:16 h, ZT0 = lights on, ZT8 = lights off, 400 lux) and the other was housed under long-day conditions (light:dark = 16 h:8 h, ZT0 = lights on, ZT16 = lights off, 400 lux) for 2 weeks. The PTs of both groups were retrieved every 4 h for 1 day (6 time points for each group), starting at ZT0. For the experiments performed during the first day of the long-day conditions, we applied two different conditions, following 3 weeks under short-day conditions. In one, the light-onset was advanced by 8 hours (advance condition), and in the other, the dark period was delayed by 8 hours (delay condition). PTs from both groups were obtained every 4 h for 1 day, starting at the lights-on time. (Lights on for the advance condition was ZT16 as defined by the short-day condition. Lights on for the delay condition was ZT0). We sampled 25 mice at each time point. This whole procedure was repeated twice (n = 2) to obtain experimental replicates.
Project description:This experiment profiled a time series of gene expression in leaf 7 of Arabidopsis thaliana plants grown in a controlled environment under 8 h light: 16 h dark (i.e. short days) to compare to the profiles analysed in Breeze et al. (2011) Plant Cell 23(3):873-94 under long day conditions.
Project description:14-3-3 proteins are involved in a number of developmental processes in plants, largely acting through the control of transcription factor localization within the cytoplasm or nucleus. The temperate Pooideae grass 14-3-3 gene GF14h in particular was previously found to be co-expressed with flowering activators in the vernalization pathway, leading to the hypotheses that its protein product is involved in vernalization responsive flowering and/or cold acclimation. To test predictions of these non-exclusive hypotheses, and to assess functional conservation broadly across angiosperms, we generated CRISPR lines of GF14h in Brachypodium distachyon (Pooideae) and compared their mutant phenotypes with those of the co-orthologous Arabidopsis thaliana (Brassicaceae) grf9 T-DNA mutant. Contrary to our first prediction, we found that rather than promoting flowering as part of the vernalization pathway, both BdGF14h and AtGRF9 repress flowering under different conditions. Our data also support a conserved role for GF14h/GRF9 genes in the promotion of growth at the expense of abiotic stress resilience. We discuss these results in the light of crop improvement and climate change.
Project description:To understand which genes acts downstream AtHB1 affecting hypocotyl growth in Arabidopsis thaliana, we performed transcriptional profiles of 4-day-old seedlings grown in a short-day regime comparing wild-type with athb1-1 mutant plants. These results show that some of the AtHB1-regulated genes modulate cell elongation, particularly cell wall composition and elongation, or encode proteins that serve as a source of carbon, nitrogen, and sulfur for early seedling growth. RNA-Seq data for 4-day-old wild-type (Col-0) and athb1-1 mutant seedlings grown under short-day conditions. Biological triplicates were performed for each genotype analyzed.