Plants regulate their time to flowering by gathering information from the environment. Photoperiod and temperature are among the most important environmental variables. Suboptimal, but not near-freezing, temperatures regulate flowering through the thermosensory pathway, which overlaps with the autonomous pathway. Here we show that ambient temperature regulates flowering by two genetically distinguishable pathways, one that requires TFL1 and another that requires ELF3. The delay in flowering time observed at lower temperatures was partially suppressed in single elf3 and tfl1 mutants, whereas double elf3 tfl1 mutants were insensitive to temperature. tfl1 mutations abolished the temperature response in cryptochrome mutants that are deficient in photoperiod perception, but not in phyB mutants that have a constitutive photoperiodic response. Contrary to tfl1, elf3 mutations were able to suppress the temperature response in phyB mutants, but not in cryptochrome mutants. The gene expression profile revealed that the tfl1 and elf3 effects are due to the activation of different sets of genes and identified CCA1 and SOC1/AGL20 as being important cross talk points. Finally, genome-wide gene expression analysis strongly suggests a general and complementary role for ELF3 and TFL1 in temperature signalling.
A complementary role for ELF3 and TFL1 in the regulation of flowering time by ambient temperature.
No sample metadata fields
View SamplesTwo aspects of light are very important for plant development: the length of the light phase or photoperiod and the quality of incoming light. Photoperiod detection allows plants to anticipate the arrival of the next season, whereas light quality, mainly the red to far-red ratio (R:FR), is an early signal of competition by neighbouring plants. phyB represses flowering by antagonising CO at the transcriptional and post-translational levels. A low R:FR decreases active phyB and consequently increases active CO, which in turn activates the expression of FT, the plant florigen. Other phytochromes like phyD and phyE seem to have redundant roles with phyB. PFT1, the MED25 subunit of the plant Mediator complex, has been proposed to act in the light-quality pathway that regulates flowering time downstream of phyB. However, whether PFT1 signals through CO and its specific mechanism are unclear. Here we show that CO-dependent and -independent mechanisms operate downstream of phyB, phyD and phyE to promote flowering, and that PFT1 is equally able to promote flowering by modulating both CO-dependent and -independent pathways. Our data are consistent with the role of PFT1 as an activator of CO transcription, and also of FT transcription, in a CO-independent manner. Our transcriptome analysis is also consistent with CO and FT genes being the most important flowering targets of PFT1. Furthermore, comparison of the pft1 transcriptome with transcriptomes after fungal and herbivore attack strongly suggests that PFT1 acts as a hub, integrating a variety of interdependent environmental stimuli, including light quality and jasmonic acid-dependent defences.
PFT1, the MED25 subunit of the plant Mediator complex, promotes flowering through CONSTANS dependent and independent mechanisms in Arabidopsis.
Specimen part
View SamplesPurpose: The aim of this study is to determine the relative expresson levels of mRNA transcripts in wild type platelets Methods: Total RNA was extracted and purified from purified platelets from BALB/c male mice (3 independent samples). Platelet purification was performed as described in Josefsson EC et al, Journal of Experimental Medicine (2011) 208:2017-31. Total RNA (100 ng) was used to generate sequencing libraries for whole transcriptome analysis following Illumina’s TruSeq RNA v2 sample preparation protocol. Completed libraries were sequenced on HiSeq 2000 with TruSeq SBS Kit v3- HS reagents (Illumina) as 100 bp paired-end reads at the Australian Genome Research Facility (AGRF), Melbourne. Reads were aligned to the mouse reference genome mm10 and counts for known genes were obtained using the Rsubread package (version 1.18.0) (Liao et al. 2013; Liao et al. 2014). Overall design: Total RNA was extracted and purified from purified platelets from BALB/c male mice (3 independent samples per population).
Loss of PUMA (BBC3) does not prevent thrombocytopenia caused by the loss of BCL-XL (BCL2L1).
Age, Specimen part, Cell line, Subject
View SamplesThe goal of this study was to identify genes which are differentiatlly expresesd upon induced inactivation of Rfx6 in beta cell in adult mice Overall design: Rfx6fl/fl; Ins1-CreERT2 (mut) and Rfx6fl/fl (ctrl) 8 weeks old mice were injected subcutaneously with tamoxifen daily during 3 days. Pancreatic islets were isolated 5 days after the first injection and RNA purified.
Rfx6 maintains the functional identity of adult pancreatic β cells.
No sample metadata fields
View SamplesHere, we report on experiments in double-transgenic mice, in which RFP is expressed in all Foxp3+ Treg cells, whereas Foxp3-dependent GFP expression is exclusively confined to intrathymically induced Foxp3+ Treg cells. This novel molecular genetic tool enabled us to faithfully track and characterize naturally induced Treg cells of intrathymic (RFP+GFP+) and extrathymic (RFP+GFP) origin in otherwise unmanipulated mice.
Fluorochrome-based definition of naturally occurring Foxp3(+) regulatory T cells of intra- and extrathymic origin.
No sample metadata fields
View SamplesAnalysis of Lin-c-Kit+Sca-1- haematopoietic stem cells (HSCs) expressing the Nup98-HoxD13 (NHD13) fusion gene. NHD13 induces myelodysplastic syndrome (MDS) in mice. Results provide insight into the molecular basis of the myelodysplastic phenotype Overall design: WT mouse HSCs were compared to an NHD13 mutant sequenced in triplicate on a HiSeq 2000
PUMA promotes apoptosis of hematopoietic progenitors driving leukemic progression in a mouse model of myelodysplasia.
No sample metadata fields
View SamplesWhilst the association of Epstein-Barr virus (EBV) with Burkitt lymphoma (BL) has long been recognized, the precise role of the virus in BL pathogenesis is not fully resolved. EBV can be lost spontaneously from some BL cell lines, and these EBV-loss lymphoma cells reportedly have a survival disadvantage. We have generated an extensive panel of EBV-loss clones from multiple BL backgrounds and examined their phenotype comparing them to their isogenic EBV-positive counterparts. Whilst loss of EBV from BL cells is rare, it is consistently associated with an enhanced predisposition to undergo apoptosis and reduced tumorigenicity in vivo. We investigated whether there were common gene expression changes between EBV-positive and loss clones derived for four endemic Burkitt lyphoma cell lines that could explain the apoptosis sensitivity of clones that had lost EBV.
Coordinated repression of BIM and PUMA by Epstein-Barr virus latent genes maintains the survival of Burkitt lymphoma cells.
Cell line
View SamplesT cell differentiation is governed by interactions with thymic epithelial cells (TECs) and defects in this process undermine immune function and tolerance. To uncover new strategies to restore thymic function and adaptive immunity in immunodeficiency, we sought to determine the molecular mechanisms that control life and death decisions in TEC. We created a mouse model which specifically deleted the pro-survival gene Mcl1 in TEC. We found that while BCL-2 and BCL-XL were dispensable for TEC homeostasis, MCL-1 deficiency impacted on TEC as early as E15.5, resulting in early thymic atrophy and T cell lymphopenia, with near complete loss of thymic tissue by 2 months of age. MCL-1 was not necessary for TEC differentiation but was continually required for the survival of medullary TEC, including autoimmune regulator (AIRE) expressing TECs and the maintenance of overall thymic architecture. To understand the molecular mechanisms in more detail, RNA-seq profiling was undertaken of cortical and medullary thymic epithelial cells (cTECs and mTECs) from wildtype and knockout mice. Overall design: The number of biological replicates was n=4 for WT cTECs, n=2 for WT mTECs, n=1 for KO cTECs and n=1 for KO mTECs.
A critical epithelial survival axis regulated by MCL-1 maintains thymic function in mice.
Cell line, Subject
View SamplesIn this study gene expression of human blood classical monocytes (CD14++CD16-), CD16 positive monocytes (consisting of non-classical CD14+16++ and intermediate CD14++CD16+ monocytes) and CD1c+ CD19- dendritic cells from healthy subjects were investigated.
Transcript profiling of CD16-positive monocytes reveals a unique molecular fingerprint.
Specimen part
View SamplesMutations in TRP53, prevalent in human cancers, reportedly drive tumorigenesis through dominant-negative-effects (DNE) over wt TRP53 and neomorphic gain-of-function (GOF) effects. We show that five TRP53 mutants do not accelerate lymphomagenesis on a TRP53-deficient background but strongly synergize with c-MYC over-expression. RNA-seq analysis revealed that mutant TRP53 does not globally repress wt TRP53 function but exerts a DNE with disproportionate impact on subsets of wt TRP53 target genes, particularly those involved in DNA repair, proliferation and metabolism. This reveals that the mutant TRP53 DNE drives tumorigenesis by modulating wt TRP53 function in a manner that is advantageous for neoplastic transformation. Overall design: Each of 5 mutant human TRP53 proteins, and a negative control, was expressed in 3 mouse lymphoma cell lines, both before and after activation of WT TRP53 with nutlin-3a.
Mutant TRP53 exerts a target gene-selective dominant-negative effect to drive tumor development.
Cell line, Subject
View Samples