Project description:We take the two year old plant for sampling.Use the Affymetrix poplar gene chip to elucidate the gene functions and mechanisms in Populus tomentosa shoot apex and mature xylem. We used microarrays to detail the global programme of gene expression in shoot apex and mature xylem. Populus tomentosa shoot apex and mature xylem were taken for RNA extraction and hybridization on Affymetrix microarrays.CB2009304-C and CB2009304-D from shoot apex, CB2009304-G and CB2009304-H from mature xylem.
Project description:We take the two year old plant for sampling.Use the Affymetrix poplar gene chip to elucidate the gene functions and mechanisms in Populus tomentosa shoot apex and mature xylem. We used microarrays to detail the global programme of gene expression in shoot apex and mature xylem.
Project description:Kilian2024 - Immune cell dynamics in Cue-Induced Extended Human Colitis Model
Single-cell technologies such as scRNA-seq and flow cytometry provide critical insights into immune cell behavior in inflammatory bowel disease (IBD). However, integrating these datasets into computational models for dynamic analysis remains challenging. Here, Kilian et al., (2024) developed a deterministic ODE-based model that incorporates these technologies to study immune cell population changes in murine colitis. The model parameters were optimized to fit experimental data, ensuring an accurate representation of immune cell behavior over time. It was then validated by comparing simulations with experimental data using Pearson’s correlation and further tested on independent datasets to confirm its robustness. Additionally, the model was applied to clinical bulk RNA-seq data from human IBD patients, providing valuable insights into immune system dynamics and potential therapeutic strategies.
Figure 4c, obtained from the simulation of human colitis model is highlighted here.
This model is described in the article:
Kilian, C., Ulrich, H., Zouboulis, V.A. et al. Longitudinal single-cell data informs deterministic modelling of inflammatory bowel disease. npj Syst Biol Appl 10, 69 (2024). https://doi.org/10.1038/s41540-024-00395-9
Abstract:
Single-cell-based methods such as flow cytometry or single-cell mRNA sequencing (scRNA-seq) allow deep molecular and cellular profiling of immunological processes. Despite their high throughput, however, these measurements represent only a snapshot in time. Here, we explore how longitudinal single-cell-based datasets can be used for deterministic ordinary differential equation (ODE)-based modelling to mechanistically describe immune dynamics. We derived longitudinal changes in cell numbers of colonic cell types during inflammatory bowel disease (IBD) from flow cytometry and scRNA-seq data of murine colitis using ODE-based models. Our mathematical model generalised well across different protocols and experimental techniques, and we hypothesised that the estimated model parameters reflect biological processes. We validated this prediction of cellular turnover rates with KI-67 staining and with gene expression information from the scRNA-seq data not used for model fitting. Finally, we tested the translational relevance of the mathematical model by deconvolution of longitudinal bulk mRNA-sequencing data from a cohort of human IBD patients treated with olamkicept. We found that neutrophil depletion may contribute to IBD patients entering remission. The predictive power of IBD deterministic modelling highlights its potential to advance our understanding of immune dynamics in health and disease.
This model was curated during the Hackathon hosted by BioMed X GmbH in 2024.
Project description:Flowering of several plant species is induced by exposure to specific photoperiods that promote the expression of florigenic proteins in the leaves and their subsequent translocation to the shoot apex, where they commit the meristem to a reproductive fate. Transition to reproductive growth at the apex is often accompanied by stem elongation, to expose flowers above the leaves and facilitate fertilization. However, how growth and inflorescence formation are coupled and how photoperiodic signals coordinate these processes at the apex is still unclear. We studied these mechanisms in rice, a short day plant. Here, we show that HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1), encoding components of the rice florigenic signal, are sufficient to repress expression of PREMATURE INTERNODE ELONGATION 1 (PINE1) at the shoot apex during the transition to flowering, thus promoting culm elongation. PINE1 encodes a nuclear C2H2 zinc finger transcriptional repressor that controls the mRNA abundance of GA3ox2, a gibberellin (GA) biosynthetic gene. These data uncover the existence of a regulatory network coordinating multiple aspects of phase transition, and indicate that GA-induced growth and activity of florigenic proteins at the shoot apex need to be strictly coupled.
Project description:Genetic changes involved in the juvenile-to-adult transition in the shoot apex of Olea europaea L. occurs years before the first flowering.
Project description:We sequenced mRNA of WT and pFD::amiR-PECT1 from shoot apex, seedling grown at 23°C short days, 10 and 16 days after germination at ZT 8