Marine systems biology

The marine environment accounts for an important part of the earth biodiversity, featuring several types of (even extreme) ecosystems, and is at the origin of life. Marine prokaryotic and eukaryotic organisms are very diverse, and are sometimes, in particular for the latter, the result of intricate evolutionary history. This biodiversity, encounters in many different habitats, shapes various types of abiotic and biotic interactions which influence the biology of the organisms and the functioning of ecosystems. To better understand these natural processes, marine scientists historically considered as valuable to gather and interface data obtained at different levels of analysis (molecular, cellular, tissue/organ, organism/individual, population, community, ecosystem), and to conduct interdisciplinary research making use of principles, knowledge and tools of different fields including biology, ecology, mathematics, physics, and more recently computer sciences. This holistic philosophy recently gains a whole new perspective by the emergence of systems biology. Initially motivated by designing new theoretical frameworks, this field quickly showed its interest for understanding the biological systems as a whole while addressing many applied integrative research problems across model species from bacteria to humans. Because of their interdisciplinary history, marine sciences today follow this momentum by expanding systems biology approaches to a broader range of marine (eco)systems. Not surprisingly, and as already observed in systems biology, these extensions rely on three complementary points. The first overcomes the problem of analyzing high throughput experiments (genomes, transcriptomes, proteomes, metabolomes), the so-called omics. The second integrates heterogeneous datasets within a unique integrative framework, such as networks or dedicated modelings that describe the marine systems of interest. The third emphasizes putative dynamical behaviors of the marine system when submitted to perturbations, via dedicated computational techniques inspired from mathematical and/or logical modeling. Interestingly, and compared to other natural systems, marine (eco)systems are, by essence, ideal benchmarks for designing new systems biology approaches since (i) as part of the global ocean, these systems are historically considered as multi-scale, and (ii) their nature allows (mostly) to replicate quantitative experiments. Thus, in addition to providing insights into the biology of marine organisms and the functioning of marine ecosystems, these approaches lay the ground for modeling and predicting evolution of marine processes under changing environmental conditions, and also for inspiring and providing some solutions for a bio-based economy. This current Frontiers Research Topic Issue on Marine Systems Biology provides examples of systems biology approaches that cover different methodological aspects and that are applied …