Search results for "eukaryotes"
showing 5 items of 5 documents
Linking extreme seasonality and gene expression in arctic marine protists
2021
ABSTRACTAt high latitudes, strong seasonal differences in light availability affect marine organisms and restrict the timing of ecosystem processes. Marine protists are key players in Arctic aquatic ecosystems, yet little is known about their ecological roles over yearly cycles. This is especially true for the dark polar night period, which up until recently was assumed to be devoid of biological activity. A 12 million transcripts catalogue was built from 0.45-10 μm protist assemblages sampled over 13 months in a time series station in an arctic fjord in Svalbard. Community gene expression was correlated with seasonality, with light as the main driving factor. Transcript diversity and evenn…
Informational, ecological and system approaches for complete genome analysis
2012
In the study of the genetic modifications leading populations to adapt to their environment, it is important to distinguish changes resulting in an increase in biological fiteness from those slightly deleterious. Besides that the concept of neutral changes is defined since the ¿Origin of species¿ by Charles Darwin, its relevance to the overall changes defining evolutionary process was considered to be very low, if existent. But, in the late sixties, with the advances of molecular experiments and the first comparative studies in this field, neutral changes were proven to be almost sufficient to explain the amount of changes per generation observed at molecular level. Based on this observatio…
Energetic coupling between plastids and mitochondria drives CO2 assimilation in diatoms.
2015
International audience; Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies prin…
Microbial and meiofaunal response to intensive mussel-farm biodeposition in coastal sediments of the Western Mediterranean
2000
We studied the impact of organic loads due to the biodeposition of a mussel farm in a coastal area of the Tyrrhenian Sea (Western Mediterranean). Sediment chemistry, microbial and meiofaunal assemblages were investigated from March 1997 to February 1998 on monthly basis at two stations: the first was located under the mussel farm, while the second was at about 1-km distance and served as control. Benthic response to changes in the biodepositional regime was investigated in terms of biochemical composition of the sedimentary organic matter, phytopigment content, bacterial abundance and composition and meiofaunal community structure. A large accumulation of chloroplastic pigments, proteins an…
KOSMOS 2017 Peru Side Experiment: nutrients, phytoplankton abundances, enzyme rates, photophysiology
2022
This data was collected during an short-term incubation experiment in March 2017 that investigated the response of a surface plankton community to upwelling. This experiment was carried in the framework of the SFB754-funded KOSMOS mesocosm study that took place in La Punta, Callao, Peru between February-April 2017. A total of six different treatments were used to disentangle chemical and biological characteristics of deep water that influence surface plankton blooms: 2 different deep water sources with different nutrient concentrations; 3 treatments to distinguish the effects of inorganic nutrients, organic nutrients and deep water microbial populations. Measured variables include inorganic…