Témoignages de chercheurs - Julie POULAIN

Summary

Julie Poulin, an engineer at Genoscope, discusses the Tara Oceans project, which aimed to explore the unknown world of marine plankton ecosystems, from viruses to fish larvae. The project focused on understanding plankton's crucial role in oxygen production and the food chain. With over 30,000 samples collected from over 200 sites, the research involved advanced genomic, chemical, and physical analyses to study biodiversity, gene expression, and ecological interactions. The project also provided insight into the impacts of climate change on these ecosystems. Julie highlights the collaborative effort of scientists and sailors, emphasizing the challenges and rewards of handling large data sets and the importance of thorough data understanding.

Takeaways

• 😀 Julie Poulin, an engineer at Genoscope, discusses her work on the Tara Oceans project, which aimed to explore marine planktonic ecosystems, including viruses and fish larvae.
• 😀 The goal of Tara Oceans was to study plankton ecosystems, which are crucial for oxygen production and the marine food chain.
• 😀 Understanding plankton ecosystems can help predict how these organisms will adapt to climate change.
• 😀 Sample collection occurred over 2.5 years, with over 200 sites and 30,000 samples gathered.
• 😀 Water was filtered to concentrate planktonic organisms, which were preserved in liquid nitrogen to maintain DNA and RNA integrity for analysis.
• 😀 Data analysis at Genoscope involved extracting DNA and RNA and using techniques like meta-barcoding, metagenomics, and metatranscriptomics.
• 😀 Meta-barcoding identifies species diversity, metagenomics sequences all DNA in the sample, and metatranscriptomics provides information on gene expression.
• 😀 The project required significant storage capacity and computational power due to the enormous volume of data generated.
• 😀 Tara Oceans' findings help map living groups and genes in the oceans and provide insight into ecological mechanisms and evolutionary changes.
• 😀 Julie emphasizes the importance of understanding the type and source of data when analyzing large datasets.

Q & A

What was the primary goal of the Tara Oceans project?

The primary goal of the Tara Oceans project was to study the previously unknown world of marine planktonic ecosystems, including viruses and fish larvae.

Why is plankton important for the Earth’s ecosystems?

Plankton is essential because it produces half of the oxygen we breathe and serves as the foundation of the marine food chain.

How were the sampling locations for the Tara Oceans project selected?

Sampling locations were chosen based on oceanographic parameters, ecological constraints, biological factors, and weather conditions. The sites were refined daily using satellite data.

How many sampling sites were analyzed during the Tara Oceans project?

More than 200 sampling sites were analyzed, and over 30,000 samples were collected.

What method was used to concentrate plankton samples from the water?

A filtration system was used to pass water through a membrane, concentrating and fixing the plankton organisms onto the membrane, which was then stored in liquid nitrogen to preserve the biological material.

What are the different types of genomic analyses conducted on the plankton samples?

The plankton samples were analyzed using metabarcoding, metagenomics, and metatranscriptomics. Metabarcoding focused on sequencing a marker gene to identify species diversity, while metagenomics involved sequencing all the DNA in the sample, and metatranscriptomics analyzed RNA to understand gene expression.

What are the key steps in processing the plankton samples for genomic analysis?

The process involved extracting DNA and RNA from the plankton on the membranes, followed by cell lysis and grinding. The DNA was then analyzed through metabarcoding and metagenomics, and the RNA was analyzed through metatranscriptomics.

What makes analyzing data from such a large-scale project challenging?

The main challenge in analyzing data from a project of this scale is the enormous volume of data, which requires substantial data storage and powerful computational capabilities.

What insights can be gained from the data collected by the Tara Oceans project?

The data can provide insights into the diversity of marine organisms, ecological mechanisms (such as how organisms live together and interact), and evolutionary processes, including genetic changes that help organisms adapt to environmental conditions.

What advice does Julie Poulin offer for analyzing complex datasets?

Julie Poulin advises first understanding the types of data you have and how they were generated, as this is crucial for knowing how to properly analyze and interpret them.