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Reichel-Deland, V.

Publications and source records attributed to Reichel-Deland, V..

3 recordsLinked to original sources

Predmoter - Cross-species prediction of plant promoter and enhancer regions

MotivationThe identification of cis-regulatory elements (CREs) is crucial for the analysis of gene regulatory networks in plants. Several next generation sequencing (NGS)-based methods were developed to identify CREs. However, these methods can be time-consuming and costly. They also involve creating sequencing libraries for the entire genome. Since many research efforts only focus on specific genomic loci, this presents a considerable expenditure. Computational prediction of the outputs of specialized NGS methods to analyze CREs, like Assay for Transposase Accessible Chromatin using sequencing (ATAC-seq), would significantly cut costs and time investment. Yet, no such method is available to date. ResultsWe present Predmoter, a deep neural network able to predict base-wise ATAC-seq and histone Chromatin immunoprecipitation DNA-sequencing (ChIP-seq) read coverage for plant genomes. Predmoter uses only the DNA sequence as input. We evaluated our model on two plant genomes, the genome of the dicot Arabidopsis thaliana and of the monocot Oryza sativa. We trained our models on 10 species with publicly available ATAC-seq data and 15 species with ChIP-seq data. Our best models showed accurate predictions in peak positions and the overall pattern of peaks for ATAC- and Histone H3 trimethylated at lysine 4 (H3K4me3) ChIP-seq. Annotating putatively accessible chromatin regions provides valuable input for the identification of CREs. In conjunction with other in silico data, such as predicted binding affinities for transcription factors (TFs), this can significantly narrow down the search space to a manageable number of experimentally verifiable DNA-protein interaction pairs. Availability and ImplementationThe source code for Predmoter is available at: https://github.com/weberlab-hhu/Predmoter along with documentation for installation and usage. Predmoter uses a single-command inference, Predmoter.py, for both training and prediction. Predmoter takes a fasta file as input and outputs an h5 file and optionally bigWig and bedGraph files. HighlightPredmoter will help identifying CREs and so gaining further insight into gene regulatory networks in plants.

bioinformatics↗

The genome of Talinum fruticosum

Research on crassulacean acid metabolism (CAM) has in recent years focused on obligate CAM species, such as Kalanchoe fedtschenkoi and pineapple (Ananas comosus). To fully understand the plasticity of the CAM pathway, its evolutionary trajectory and regulation, genomic resources of additional species, including facultative CAM species are desirable. To this end, we sequenced the genome and full-length transcripts (Iso-Seq) of the facultative CAM dicot Talinum fruticosum. The provided resources may aid in CAM engineering as an approach to improving crop water-use efficiency.

plant biology↗

Transposable elements contribute to the establishment of the glycine shuttle in Brassicaceae species

C3-C4 intermediate photosynthesis has evolved at least five times convergently in the Brassicaceae, despite this family lacking bona fide C4 species. The establishment of this carbon concentrating mechanism is known to require a complex suite of ultrastructural modifications as well as changes in spatial expression patterns, which are both thought to be underpinned by a reconfiguration of existing gene-regulatory networks. However, to date, the mechanisms which underpin the reconfiguration of these gene networks are largely unknown. In this study, we used a pan-genomic association approach to identify genomic features that could confer differential gene expression toward the C3-C4 intermediate state by analysing eight C3 species and seven C3-C4 species from five independent origins in the Brassicaceae. We found a strong correlation between transposable element (TE) insertions in cis-regulatory regions and the C3-C4 intermediacy. Specifically, our study revealed 113 gene models in which presence of a TE within a gene correlates with C3-C4 intermediate photosynthesis. In this set, genes involved in the photorespiratory glycine shuttle are enriched, including the glycine decarboxylase P-protein whose expression domain undergoes a spatial shift during the transition to C3-C4 photosynthesis. When further interrogating this gene, we discovered independent TE insertions in its upstream region which we conclude to be responsible for causing the spatial shift in GLDP1 gene expression. Our findings hint at a pivotal role of TEs in the evolution of C3-C4 intermediacy, especially in mediating differential spatial gene expression.

plant biology↗