Detection of evolutionary conserved and accelerated genomic regions related to adaptation to thermal niches in lizards.

Understanding the genetic basis for adapting to thermal environments is important due to serious effects of global warming on ectothermic species. Various genes associated with thermal adaptation in lizards have been identified mainly focusing on changes in gene expression or the detection of positively selected genes using coding regions. Only a few comprehensive genome-wide analyses have included noncoding regions.

A practical assembly guideline for genomes with various levels of heterozygosity.

Although current long-read sequencing technologies have a long-read length that facilitates assembly for genome reconstruction, they have high sequence errors. While various assemblers with different perspectives have been developed, no systematic evaluation of assemblers with long reads for diploid genomes with varying heterozygosity has been performed. Here, we evaluated a series of processes, including the estimation of genome characteristics such as genome size and heterozygosity, de novo assembly, polishing, and removal of allelic contigs, using six genomes with various heterozygosity levels.

A novel structural maintenance of chromosomes (SMC)-related protein family specific to Archaea.

The ATPases belonging to the structural maintenance of chromosomes (SMC) superfamily are involved in the maintenance of chromosome organization and dynamics, as well as DNA repair. The major proteins in this superfamily recognized to date are either conserved among the three domains of Life (i.e.

Comparative Plastid Genomics of Green-Colored Dinoflagellates Unveils Parallel Genome Compaction and RNA Editing.

Dinoflagellates possess plastids that are diverse in both pigmentation and evolutionary background. One of the plastid types found in dinoflagellates is pigmented with chlorophylls and (Chl + ) and originated from the endosymbionts belonging to a small group of green algae, Pedinophyceae. The Chl + -containing plastids have been found in three distantly related dinoflagellates spp.

Genome evolution of a nonparasitic secondary heterotroph, the diatom .

Secondary loss of photosynthesis is observed across almost all plastid-bearing branches of the eukaryotic tree of life. However, genome-based insights into the transition from a phototroph into a secondary heterotroph have so far only been revealed for parasitic species. Free-living organisms can yield unique insights into the evolutionary consequence of the loss of photosynthesis, as the parasitic lifestyle requires specific adaptations to host environments.

Signs of the plastid: Enzymes involved in plastid-localized metabolic pathways in a eugregarine species.

Apicomplexa mainly comprises parasitic species and some of them, which infect and cause severe diseases to humans and livestock, have been extensively studied due to the clinical and industrial importance. Besides, apicomplexans are a popular subject of the studies focusing on the evolution initiated by a secondary loss of photosynthesis. By interpreting the position in the tree of eukaryotes and lifestyles of the phylogenetic relatives parsimoniously, the extant apicomplexans are predicted to be the descendants of a parasite bearing a non-photosynthetic (cryptic) plastid.

Rappemonads are haptophyte phytoplankton.

Rapidly accumulating genetic data from environmental sequencing approaches have revealed an extraordinary level of unsuspected diversity within marine phytoplankton, which is responsible for around 50% of global net primary production. However, the phenotypic identity of many of the organisms distinguished by environmental DNA sequences remains unclear. The rappemonads represent a plastid-bearing protistan lineage that to date has only been identified by environmental plastid 16S rRNA sequences.

Detection of genes positively selected in Cuban lizards that naturally inhabit hot and open areas and currently thrive in urban areas.

Species of lizards of the West Indies that naturally inhabit hot and open areas also tend to thrive in urban areas. In this study, transcriptome was sequenced for nine species of Cuban lizards that are closely related to each other, but inhabit different thermal microhabitats. Using PAML and HyPhy software, we attempted to identify genes and amino acid sites under positive selection in the common ancestral branch of and , and the branch of , which inhabit hot and open areas, and thrive in urban areas.

Putative genome features of relic green alga-derived nuclei in dinoflagellates and future perspectives as model organisms.

Nucleomorphs, relic endosymbiont nuclei, have been studied as a model to elucidate the evolutionary process of integrating a eukaryotic endosymbiont into a host cell organelle. Recently, we reported two new dinoflagellates possessing nucleomorphs, and proposed them as new models in this research field based on the following findings: genome integration processes are incomplete, and the origins of the endosymbiont lineages were pinpointed. Here, we focused on the nucleomorph genome features in the two green dinoflagellates and compared them with those of the known nucleomorph genomes of cryptophytes and chlorarachniophytes.

Dinoflagellates with relic endosymbiont nuclei as models for elucidating organellogenesis.

Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already ceased in both cryptophytes and chlorarachniophytes, implying that the organellogenesis at the genetic level has been completed in the two systems. Moreover, we have yet to pinpoint the closest free-living relative of the endosymbiotic alga engulfed by the ancestral chlorarachniophyte or cryptophyte, making it difficult to infer how organellogenesis altered the endosymbiont genome.

The draft genome of Kipferlia bialata reveals reductive genome evolution in fornicate parasites.

The fornicata (fornicates) is a eukaryotic group known to consist of free-living and parasitic organisms. Genome datasets of two model fornicate parasites Giardia intestinalis and Spironucleus salmonicida are well annotated, so far. The nuclear genomes of G.

Genomic divergence within non-photosynthetic cyanobacterial endosymbionts in rhopalodiacean diatoms.

Organelle acquisitions via endosymbioses with prokaryotes were milestones in the evolution of eukaryotes. Still, quite a few uncertainties have remained for the evolution in the early stage of organellogenesis. In this respect, rhopalodiacean diatoms and their obligate cyanobacterial endosymbionts, called spheroid bodies, are emerging as new models for the study of organellogenesis.

Genome sequencing reveals metabolic and cellular interdependence in an amoeba-kinetoplastid symbiosis.

Endosymbiotic relationships between eukaryotic and prokaryotic cells are common in nature. Endosymbioses between two eukaryotes are also known; cyanobacterium-derived plastids have spread horizontally when one eukaryote assimilated another. A unique instance of a non-photosynthetic, eukaryotic endosymbiont involves members of the genus Paramoeba, amoebozoans that infect marine animals such as farmed fish and sea urchins.

Diversity of the Photosynthetic Paulinella Species, with the Description of Paulinella micropora sp. nov. and the Chromatophore Genome Sequence for strain KR01.

The thecate filose amoeba Paulinella chromatophora is a good model organism for understanding plastid organellogenesis because its chromatophore was newly derived from an alpha-cyanobacterium. Paulinella chromatophora was the only known photosynthetic Paulinella species until recent studies that suggested a species level of diversity. Here, we described a new photosynthetic species P.

Metabolic Capacity of Mitochondrion-related Organelles in the Free-living Anaerobic Stramenopile Cantina marsupialis.

Functionally and morphologically degenerate mitochondria, so-called mitochondrion-related organelles (MROs), are frequently found in eukaryotes inhabiting hypoxic or anoxic environments. In the last decade, MROs have been discovered from a phylogenetically broad range of eukaryotic lineages and these organelles have been revealed to possess diverse metabolic capacities. In this study, the biochemical characteristics of an MRO in the free-living anaerobic protist Cantina marsupialis, which represents an independent lineage in stramenopiles, were inferred based on RNA-seq data.

Complete genome of a nonphotosynthetic cyanobacterium in a diatom reveals recent adaptations to an intracellular lifestyle.

The evolution of mitochondria and plastids from bacterial endosymbionts were key events in the origin and diversification of eukaryotic cells. Although the ancient nature of these organelles makes it difficult to understand the earliest events that led to their establishment, the study of eukaryotic cells with recently evolved obligate endosymbiotic bacteria has the potential to provide important insight into the transformation of endosymbionts into organelles. Diatoms belonging to the family Rhopalodiaceae and their endosymbionts of cyanobacterial origin (i.

Broad distribution of TPI-GAPDH fusion proteins among eukaryotes: evidence for glycolytic reactions in the mitochondrion?

Glycolysis is a central metabolic pathway in eukaryotic and prokaryotic cells. In eukaryotes, the textbook view is that glycolysis occurs in the cytosol. However, fusion proteins comprised of two glycolytic enzymes, triosephosphate isomerase (TPI) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), were found in members of the stramenopiles (diatoms and oomycetes) and shown to possess amino-terminal mitochondrial targeting signals.

Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs.

Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote-eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans.

Evolving a photosynthetic organelle.

The evolution of plastids from cyanobacteria is believed to represent a singularity in the history of life. The enigmatic amoeba Paulinella and its 'recently' acquired photosynthetic inclusions provide a fascinating system through which to gain fresh insight into how endosymbionts become organelles.The plastids, or chloroplasts, of algae and plants evolved from cyanobacteria by endosymbiosis.

Cercozoa comprises both EF-1α-containing and EFL-containing members.

Elongation factor 1α (EF-1α) and elongation factor-like protein (EFL) are considered to be functionally equivalent proteins involved in peptide synthesis. Eukaryotes can be fundamentally divided into 'EF-1α-containing' and 'EFL-containing' types. Recently, EF-1α and EFL genes have been surveyed across the diversity of eukaryotes to explore the origin and evolution of EFL genes.

Spheroid bodies in rhopalodiacean diatoms were derived from a single endosymbiotic cyanobacterium.

Members of the diatom family rhopalodiaceae possess cyanobacteria-derived intracellular structures called spheroid bodies (SBs) that very likely carry out nitrogen fixation. Due to the shortage of molecular data from SBs and rhopalodiacean diatoms, it remains unclear how SBs were established and spread in rhopalodiacean diatoms. We here amplified the small subunit ribosomal DNA sequences from both host and SB in three rhopalodiacean diatom species, Epithemia turgida, E.