Department of Integrative Marine Ecology
Director of Studies: Maria I. Ferrante
Project Summary/Abstract
Signal transduction mechanisms are extremely well defined in multicellular organisms and unicellular model systems such as yeast and Chlamydomonas but very little is known for phytoplankton. Yet, understanding how cells sense and integrate environmental signals is fundamental to explain population dynamics, community interactions and ultimately ecosystem functioning.
Diatoms, among phytoplanktonic organisms, are one of the most important and abundant groups and, because of the availability of genomic data and genetic resources for a selection of species, represent currently the most suitable system to approach molecular and functional studies.
Among the possible signals that a cell can send and receive, we have chosen to investigate the chemical communication during sexual reproduction in the pennate marine diatom Pseudo-nitzschia multistriata, a species for which we produced a reference genome and transcriptomes.
We undertook gene expression studies to investigate the pathways and gene networks used by diatoms to process the signals. The data revealed complex changes in gene expression of cells engaged in the initial phases of sexual reproduction. Importantly, we observed changes in the expression of genes well-characterized in animals or plants but so far scarcely or not at all described for diatoms.
This project aims at developing on these findings, providing further support to the hypothesis that specific signaling pathways well described in other systems are active in diatoms and are being used to process the reception of chemical cues (pheromones). This will be done by expanding the studies on gene expression, and by perturbation experiments, exploiting functional genomics techniques recently developed in the laboratory.
The data generated will allow to define gene networks in diatoms and to carry out comparative studies to identify specific and general characteristics of diatom responses to external stimuli.
Eventually, we will integrate the information obtained in the laboratory with metagenomics and metatranscriptomics data collected across the world’s oceans, such as data collected during the TARA Oceans expedition, strengthening the integration of environmental and experimental data.
