The current consensus for the eukaryote tree of life consists several large assemblages (supergroups) that are hypothesized to describe existing diversity. Phylogenomic analyses have shed light on evolutionary relationships within and between supergroups as well placed newly sequenced enigmatic species close known lineages. Yet, a few remain unknown origin could represent key forms inferring ancient genomic cellular characteristics eukaryotes. Here, we investigate poorly studied protist...

In animals, cellularization of a coenocyte is specialized form cytokinesis that results in the formation polarized epithelium during early embryonic development. It characterized by coordinated assembly an actomyosin network, which drives inward membrane invaginations. However, whether driven invagination exists outside animals not known. To end, we investigate ichthyosporean Sphaeroforma arctica, close unicellular relative animals. We show process involves plasma invaginations dependent on...

The aquatic bacterial group SAR11 is one of the most abundant organisms on Earth, with an estimated global population size 2.4 × 1028 cells in oceans. Members have also been detected brackish and fresh waters, but evolutionary relationships between species present different environments ambiguous. In particular, it was not clear how frequently this lineage has crossed saline–freshwater boundary during its diversification. Due to huge potential microbes for long-distance dispersal, we...

The emergence of multicellular animals was associated with an increase in phenotypic complexity and the acquisition spatial cell differentiation embryonic development. Paradoxically, this transition not paralleled by major changes underlying developmental toolkit regulatory networks. In fact, most these systems are ancient, established already unicellular ancestors [1Shalchian-Tabrizi K. Minge M.A. Espelund M. Orr R. Ruden T. Jakobsen K.S. Cavalier-Smith Multigene phylogeny choanozoa origin...

The cryptomonads is a well-defined lineage of unicellular eukaryotes, composed several marine and freshwater groups. However, the evolutionary relationships among these groups are unclear due to conflicting inferences between morphological molecular phylogenies. Here, we have inferred species in order better understand importance marine-freshwater boundary on historical diversification patterns cryptomonads. We constructed improved phylogenies by taking into account rate variation both...

Radiolarians are marine planktonic protists that belong to the eukaryote supergroup Rhizaria together with Foraminifera and Cercozoa. Radiolaria has traditionally been divided into four main groups based on morphological characters; i.e. Polycystina, Acantharia, Nassellaria Phaeodaria. But recent 18S rDNA phylogenies have shown Phaeodaria belongs within Cerocozoa, previously heliozoan group Taxopodida should be included in Radiolaria. not yet resolved sister relationship between groups, but...

The innovation of the eukaryote cytoskeleton enabled phagocytosis, intracellular transport, and cytokinesis, is largely responsible for diversity morphologies among eukaryotes. Still, relationship between phenotypic innovations in their underlying genotype poorly understood. To explore genetic mechanism morphological evolution eukaryotic cytoskeleton, we provide first single cell transcriptomes from uncultured, free-living unicellular eukaryotes: polycystine radiolarian Lithomelissa setosa...

Abstract Background Recent surveys of eukaryote 18S rDNA diversity in marine habitats have uncovered worldwide distribution the heterotrophic phylum Telonemia. Here we investigate and geographic Telonemia sequences by in-depth sequencing several new clone libraries from both freshwater sites using a Telonemia-specific PCR strategy. Results In contrast to earlier studies that employed eukaryote-wide design, identified large unknown phylotypes first rigorous evidence for species, altogether...

Hydrurus foetidus is a geographically widespread alga commonly detected as 2–10 cm thalli in mountain streams early spring, and also lowland rivers at latitudes where seasonal conditions are appropriate for this cold-water species. Reaching macroscopic dimensions but with pronounced phenotypic plasticity, species not typical the golden algae (Chrysophyceae) – they almost exclusively microscopic organisms, best known micro- or nanoplankton fresh water. Other sessile multicellular members less...

Abstract The emergence of the SARS-CoV-2 virus led to a global pandemic, prompting extensive research efforts understand its molecular biology, transmission dynamics, and pathogenesis. Recombination events have been increasingly recognized as significant contributor virus’s diversity evolution, potentially leading novel strains with altered biological properties. Indeed, recombinant lineages such XBB variant descendants subsequently dominated globally. Therefore, continued surveillance...

<ns3:p>Background microRNAs (miRNAs) are key post-transcriptional regulators of gene expression in animals, yet their origins and early functions remain elusive. In this study, we explore the diversity functionality miRNAs Ichthyosporea, a group unicellular organisms that represent some closest relatives animals. Methods We have performed miRNA identification by integrating deep small RNA sequencing with draft genome assemblies across six species including <ns3:italic>Abeoforma...

ABSTRACT. The Haptophyta is a common algal group in many marine environments, but only few species have been observed freshwaters, with DNA sequences available from just single species, Crysochromulina parva Lackey, 1939. Here we investigate the haptophyte diversity high mountain lake, Lake Finsevatn, Norway, targeting variable V4 region of 18S rDNA gene PCR and 454 pyrosequencing. In addition, freshwater Pavlovophyceae was investigated by lineage‐specific PCR‐primers clone library...

Long non-coding RNAs (lncRNAs) play important regulatory roles during animal development, and it has been hypothesized that an RNA-based gene regulation was for the evolution of developmental complexity in animals. However, most studies lncRNA have performed using model species, very little is known about this type non-bilaterians. We therefore analysed RNA-Seq data derived from a comprehensive set embryogenesis stages calcareous sponge Sycon ciliatum identified hundreds developmentally...

Here, we present new transcriptome sequencing data from seven species of Dasycladales (Ulvophyceae) and a phylogenomic analysis the Chlorophyta with particular focus on Ulvophyceae. We have focused broad selection green algal groups carefully selected genes suitable for reconstructing deep eukaryote evolutionary histories. Increasing taxon sampling restructures Ulvophyceae by identifying as closely related to Scotinosphaerales Oltmannsiellopsidales. Contrary previous studies, do not find...

ABSTRACT. Two new classes Synchromophyceae and Picophagea, belonging to the heterokonts, have been proposed recently in separate studies of 18S rRNA phylogenies. Here we revise phylogeny these by including all available sequenced species applying Bayesian maximum likelihood methods; Synchroma grande groups with photophagotrophic Chlamydomyxa labyrinthuloides high statistical support. This clade is sister Chrysophyceae, together they share a common ancestry. Our results show that creation...

As the COVID-19 pandemic swept through an immunologically naïve human population, academics and public health professionals scrambled to establish methods platforms for genomic surveillance data sharing. This offered a rare opportunity study ecology evolution of SARS-CoV-2 over course ongoing pandemic. Here, we use population genetic phylogenetic methodology characterize dynamics reconstruct patterns virus introductions local transmission in Norway against this backdrop. The analyses...

Summary In animals, cellularization of a coenocyte is specialized form cytokinesis that results in the formation polarized epithelium during early embryonic development. It characterized by coordinated assembly an actomyosin network, which drives inward membrane invaginations. However, whether driven invagination exists outside animals not known. To end, we investigate ichthyosporean Sphaeroforma arctica , close unicellular relative animals. We show process involves plasma invaginations...

<ns4:p><ns4:italic>Hydrurus</ns4:italic> <ns4:italic>foetidus</ns4:italic> is a freshwater chrysophyte alga. It thrives in cold rivers polar and high alpine regions. has several morphological traits reminiscent of single-celled eukaryotes, but can also form macroscopic thalli. Despite its ability to produce polyunsaturated fatty acids, life under conditions variable morphology, very little known about genome transcriptome. Here, we present an extensive set next-generation sequencing data,...

Hydrurusfoetidus is a freshwater alga belonging to the phylum Heterokonta. It thrives in cold rivers polar and high alpine regions. has several morphological traits reminiscent of single-celled eukaryotes, but can also form macroscopic thalli. Despite its ability produce polyunsaturated fatty acids, life under conditions variable morphology, very little known about genome transcriptome. Here, we present an extensive set next-generation sequencing data, including genomic short reads from...

Acetabularia acetabulum is a single-celled green alga which has historically been an important model system in cell biology. Here, we attempt to re-introduce A. as through the investigation of subcellular localization mRNAs. macroscopic with highly complex cellular morphology. The gigantic, and single nucleus, located at basal end, several centimeters away from umbrella-shaped tip. To better understand genetic basis morphology this alga, aimed characterize mRNA composition four different...