NERITES : Nitrate availability Effect over RhythmIc diel TranscriptomEs in raphidocelis Subcapitata


Welcome to NERITES a web application that allows you to easily and autonomously explore the response of Raphidocelis subcapitata to nitrate stress over time and photoperiod.


Rhythmicity

Explore rhythmicity changes under stress

Gene Network

Find interesting coexpression patterns

Predictive model

Inspect our predictive model


  1. Explore rhythmicity . Enables the user to explore how rhythmic genes are affected by photoperiod and abiotic stress (nitrate availability) to which R. subcapitata is subjected.

  2. Gene Coexpression Network . If desired, the user can browse the R. subcapitata co-expression network generated from multiple conditions (nitrate availability, photoperiod and daytime) to determine potentially important connections between genes.

  3. Predictive model . To determine whether there is indeed a direct relationship between genes, a predictive model has been made available that shows the most notable connections between particular genes.




rafi


The freshwater Cholorophyta unicellular microalga Raphidocelis subcapitata (formerly known as Selenastrum capricornutum and Pseudokirchneriella subcapitata ) was originally harvested and isolated from the Nitelva River (Akershus, Norway) in 1959. (NORCCA 2023a). Its presence has been widely reported, all over the world. It is characterised by a crescent-shaped morphology with a dense cell wall and a single large chloroplast that occupies almost the entire interior of the cell.




This microalga began to be used as a marker of toxicity in fresh waters as it is very sensitive to many types of pollutants. However, in recent years, a potential biotechnological application of this micro-organism as a fixer of atmospheric CO2 and as a means of producing high-value compounds and biofuels has been seen.


Rhythmicity

Explore how rhythmicity changes under stress


NERITES allows researchers to explore the expression profiles of individual genes in Raphidocelis subcapitata and analyse their rhythmicity. This data has been generated in our lab over three complete diurnal cycles under long day (summer day, 16h light / 8h dark) and short day (winter day, 8h light / 16h dark) conditions. In this app, users can visualize gene expression profiles of their interest, compare their patterns under short day and long day conditions. Users can also perform statistical analysis over the rhythmicity of gene expression profiles. Follow the next steps to perform your analysis

Photoperiod selection

Please select the desired photoperiod from the following list for performing the analysis:

Nitrate availability

Please select the desired nitrate condition from the following list for performing the analysis:

Gene of interest

Below you can write the ID associated to the gene whose rhythmicity you wish to analyze.

Please be patient, building graph ...


Results

Results for the query gene are displayed below, arranged in different tabs. The execution of each analysis is initiated from the Start button within each of the tabs, with specific instructions for each analysis.


This tab shows two results. First of all you can see how your gene adapt along the day in every condition by a graphical representation. In other instance, you can see if your gene is rhythmic or not according to a non-parametric test (RAIN).



Finally, this tab shows several measurements (mesor, phase and amplitude) for your gene in each condition

Gene Network

Build your own gene coexpression network


The aim of this section is to facilitate the studies over the Raphidocelis subcapitata transcriptome. A user can search for a set of genes of interest using the Module Selection panel. After selecting the module you could watch his position in the network and explore their correlation with several fisiological effects.

Module Selection:



Results

The Raphidocelis subcapitata transcriptome network are displayed below. The execution of the Start button enable the visualization of the selected modules in the network. Below you can see a heatmap with the correlations values of your selected module with some physiological factor such as photoperiod, nitrate availability, time point and total fatty acid amount. Correlation values range from -1 being the most negative correlation to 1 being the most positive. In brackets we find the adjusted p-value of the correlation result.

Predictive model

Inspect your own predictive model


To determine potential relationships in fatty acid metabolism, an sPLS-type predictive model has been implemented. Partial Least Squares, or projection to latent structures (PLS), is a robust and malleable method based on multivariate projection that can be used to explore or explain the relationship between two continuous data sets. Specifically, Sparse Partial Least Squares (sPLS) is a modality of it that is able to perform simultaneous selection of variables in both data sets and thus extract the most relevant information.

Fatty Acid Selection:



Results

As a result, the weight (from 0 to 1) of the selected fatty acid in the model and those transcription factors to which it is related are shown.

Contact and Info

Acknowledgments and other information


Authors: Emma Serrano Pérez, Mercedes García González and Francisco José Romero Campero.

We are strongly committed to open access software and open science. NERITES's source code is available at GitHub following the lateral panel link and is released under a GNU General Public License v3.0. If you experience any problem using NERITES, please create an issue in GitHub and we will address it. For other inquiries, send an email to eserrano3@us.es.

The architecture of this web application was developed following the model established in our research group by PhD student Marcos Ramos González.