wynalazki: Protist

Evidence: 48 • authority: 72

Eukaryogenesis, the process which created the eukaryotic cell and lineage, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The process is widely agreed to have involved symbiogenesis, in which an archaean and one or more bacteria contributed to the lineage leading to the last eukaryotic common ancestor (LECA). It appears also to have involved horizontal gene transfers from other groups of bacteria, with some of these transfers mediated by giant viruses. The LECA had a new level of complexity and capability, with a nucleus, facultatively aerobic mitochondria, sex (meiosis and syngamy), flagella, a dormant cyst with a…

Evidence: 41 • authority: 92

Biochar amendment enhances the diversity of phagotrophic and phototrophic protists in citrus orchard soils via fungal-mediated pathways.. Soil acidification severely constrains citrus production across the globe. Biochar, as a soil conditioner, demonstrates potential for enhancing citrus yields and mitigating soil acidity; however, its influence on protist communities in citrus orchard soils remains poorly understood, particularly under field conditions. A field experiment was conducted with different biochar amendments (derived from swine manure, rice straw, and wood) in this study. Soil properties and the biotic community (fungi, bacteria, and metazoa) were analyzed. High-throughput seque…

Evidence: 41 • authority: 72

A protist () is any eukaryotic organism (one with cells containing a nucleus) that is not an animal, plant, or fungus. The protists do not form a natural group, or clade, since they exclude certain eukaryotes with whom they share a common ancestor; but, like algae or invertebrates, the grouping is used for convenience. In some systems of biological classification, such as the five-kingdom scheme proposed by Robert Whittaker in 1969, the protists make up a kingdom called Protista, composed of "organisms which are unicellular or unicellular-colonial and which form no tissues". In the 21st century, the classification shifted toward a phylogenetic classification of protists. The following group…

Evidence: — • authority: 88

Deep‐branching eukaryotes and early events in protist evolution. ABSTRACT The first eukaryotes evolved from their archaean ancestors in the early Proterozoic, likely ca . 2000–1800 million years ago (Mya). Their macroscopic multicellular descendants, such as plants, heterokont algae, animals and fungi, appeared hundreds of million years later. During this intermediate period of eukaryote evolution, dozens of important protist lineages emerged, either unicellular or with only simple forms of multicellularity. Recent discoveries and phylogenetic analyses point to the branching order at the base of the eukaryote family tree and suggest a sequence of evolutionary and ecological events that like…

Evidence: — • authority: 92

Distinct genomic adaptations of the methanogenic archaeal genus <i>Methanocorpusculum</i> to symbiosis with animals and protists. Most of our understanding of endosymbiosis originates from the bacterial endosymbionts of multicellular, terrestrial hosts, which represent habitats with dramatically different selective pressures than inside a protist cell. Methanogenic archaea from the genus Methanocorpusculum are among the few known intracellular archaea and form unique symbioses with both animal and protist hosts, providing a unique opportunity to contrast symbiont evolution and function in very distinct host types. Here, we conducted phylo- and pangenomic analyses on 106 Methanocorpusculum s…

Evidence: — • authority: 92

Molecular Insights into Nutrient-Driven Regulation of Trophic Strategies and Life Cycle Shifts in Bloom-Forming Mixotrophic Dinoflagellates. Research into molecular machinery of eukaryotic unicellular organisms (protists) gives a unique opportunity to unveil mechanisms of intricate cellular processes and complete life cycles at the level of a single cell as a whole organism. Knowledge of protistan molecular biology and life cycle shifts as adaptations to varying physical-chemical features of the environment helps resolve important issues like evaluation of the balance between external abiotic triggers and internal molecular drivers of cells development. Understanding molecular mechanisms of…

Evidence: — • authority: 92

Rare microbial relict sheds light on an ancient eukaryotic supergroup.. During the past decade, our understanding of eukaryotic evolution has increased immensely. Newly recognized eukaryotic supergroups have been established 1-3 , and most enigmatic orphan lineages have had their relationships resolved 4-6 . Studies on unicellular protist eukaryotes have also been key to understanding the evolution of mitochondria, the fundamental organelles of the eukaryotic cell, which originated from an alphaproteobacterial ancestor. The retention of ancestral alphaproteobacterial pathways in some protist lineages reveals that the mitochondrion of the last eukaryotic common ancestor was more metabolicall…

Evidence: — • authority: 92

Evolution and Adaptation of the Mitochondrial Protein Import Machinery in Parasitic Protists: Beyond the Canonical TOM Complex.. The translocase of the outer membrane (TOM) complex is the primary entry gate for nucleus-encoded mitochondrial proteins and is conserved across eukaryotes; however, parasitic protists exhibit remarkable adaptations. This review synthesizes current knowledge on the composition, structure, and function of TOM and related import systems in apicomplexans, kinetoplastids, and anaerobic protists with reduced mitochondrion-related organelles (MROs). We highlight major evolutionary innovations, including the bacterial-origin ATOM complex in trypanosomes-comprising core c…

Evidence: — • authority: 92

Single-cell genomics reveals complex microbial and viral associations in ciliates and testate amoebae.. Protists play important roles in nutrient cycling across ecosystems, yet the composition and function of their associated microbiomes remain poorly studied. Here, we use cultivation-independent single-cell isolation and genome-resolved metagenomics to investigate the microbiomes and viromes of more than 100 uncultivated ciliates and amoebae from diverse environments. Our findings reveal unique microbiome structures and complex associations with bacterial symbionts and viruses, with stark differences between ciliates and amoebae. We recover 117 microbial genomes affiliated with known eukar…

Evidence: — • authority: 92

Phylogenomic frameworks from deep archaeplastid evolution to embryophyte diversification.. All photosynthesizing eukaryotes that are the major constituents of our biosphere can ultimately be traced back to the lineage of Archaeplastida. The Archaeplastida emerged in one of the great singularities that occurred during evolution, when the cyanobacterial progenitor of all plastids was engulfed by a heterotrophic protist. Not only did the immense diversity of primary plastid-housing red algae, green algae, plants, and more emerge from this unique event but so did, through secondary endosymbioses, other diverse major lineages like diatoms and kelps. Here, we focus on the primary plastid-bearing…

Evidence: — • authority: 65