Publications by authors named "Tomoaki Nishiyama"

Over the last decade, collaborative efforts in plant evolutionary research have elucidated the phylogenetic relationships in the green plant lineage and provided insights into the emergence of land plants from a group of terrestrial and freshwater streptophyte algae. A foremost finding was that the genetic underpinnings of several key traits emerged much earlier than land plants - they were present in their streptophyte algal progenitors. Currently, the field is at a crossroads, transitioning from genomics-informed descriptions of streptophyte algae to a functional understanding of molecular mechanisms underlying their unique physiology, as well as to understanding their origin and evolution.

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Herpes simplex virus 1 (HSV-1) is the most common cause of viral encephalitis, which can be lethal or result in severe neurological defects despite antiviral therapy. The apolipoprotein B messenger-RNA editing enzyme, catalytic polypeptide-like (APOBEC) group of proteins can act as viral restriction factors. How HSV-1 evades this intrinsic immune mechanism is unclear.

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Locust bean (Ceratonia siliqua) accumulates the galactomannan (GM) locust bean gum (LBG) in its seeds. LBG is a major industrial raw material used as a food thickener and gelling agent, whose unique properties mean that it cannot be readily replaced by other GMs. Whereas much is known about GM accumulation and the genes associated with GM biosynthesis in legumes, the genes involved in GM biosynthesis in C.

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Introduction: Autism spectrum disorders (ASD) represent a heterogeneous group of neurodevelopmental disorders with strong genetic predispositions. Although an increasing number of genetic variants have been implicated in the pathogenesis of ASD, little is known about the relationship between ASD-associated genetic variants and individual ASD traits. Therefore, we aimed to investigate these relationships.

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Article Synopsis
  • The study investigates how body shape and size diversity in beetles, specifically within the genus Carabus, correlates with species richness and evolutionary processes.
  • Researchers identified a key gene, odd-paired (opa), that controls the morphological differences between slender and stout body shapes linked to different feeding methods.
  • The findings suggest that changes in the regulatory sequences of the opa gene may explain the variations in shape and size between subspecies, highlighting its potential importance in beetle adaptation and evolution.
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The evolutionary transitions of mating systems between outcrossing and self-fertilization are often suggested to associate with the cytological and genomic changes, but the empirical reports are limited in multicellular organisms. Here we used the unicellular zygnematophycean algae, the Closterium peracerosum-strigosum-littorale (C. psl.

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Genome sizes are known to vary within and among closely related species, but the knowledge about genomic factors contributing to the variation and their impacts on gene functions is limited to only a small number of species. This study identified a more than 2-fold heritable genome size variation among the unicellular Zygnematophycean alga, Closterium peracerosum-strigosum-littorale (C. psl.

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The Japanese rhinoceros beetle Trypoxylus dichotomus is a giant beetle with distinctive exaggerated horns present on the head and prothoracic regions of the male. T. dichotomus has been used as a research model in various fields such as evolutionary developmental biology, ecology, ethology, biomimetics, and drug discovery.

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Plant cells are surrounded by a cell wall and do not migrate, which makes the regulation of cell division orientation crucial for development. Regulatory mechanisms controlling cell division orientation may have contributed to the evolution of body organization in land plants. The GRAS family of transcription factors was transferred horizontally from soil bacteria to an algal common ancestor of land plants.

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Mycorrhizae are one of the most fundamental symbioses between plants and fungi, with ectomycorrhizae being the most widespread in boreal forest ecosystems. Ectomycorrhizal fungi are hypothesized to have evolved convergently from saprotrophic ancestors in several fungal clades, especially members of the subdivision Agaricomycotina. Studies on fungal genomes have identified several typical characteristics of mycorrhizal fungi, such as genome size expansion and decreases in plant cell-wall degrading enzymes (PCWDEs).

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The Closterium peracerosum-strigosum-littorale complex (Closterium, Zygnematophyceae) has an isogamous mating system. Members of the Zygnematophyceae are the closest relatives to extant land plants and are distantly related to chlorophytic models, for which a genetic basis of mating type (MT) determination has been reported. We thus investigated MT determination in Closterium.

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Article Synopsis
  • Land plant spermatozoids have unique features like spline structures, multilayered structures, and multiple flagella, but the processes behind their development (spermatogenesis) are not fully understood.
  • Researchers identified specific genes, known as BLD10s, that play a crucial role in sperm development by analyzing genetic data and testing their functions in liverworts and mosses.
  • Mutations in BLD10 genes lead to issues in cell structure during sperm formation, indicating that these genes are important for proper chromatin organization and cellular changes necessary for sperm production.
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In flowering plants, strigolactones (SLs) have dual functions as hormones that regulate growth and development, and as rhizosphere signaling molecules that induce symbiosis with arbuscular mycorrhizal (AM) fungi. Here, we report the identification of bryosymbiol (BSB), an SL from the bryophyte Marchantia paleacea. BSB is also found in vascular plants, indicating its origin in the common ancestor of land plants.

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Cytoplasmic streaming with extremely high velocity (∼70 μm s) occurs in cells of the characean algae (). Because cytoplasmic streaming is caused by myosin XI, it has been suggested that a myosin XI with a velocity of 70 μm s, the fastest myosin measured so far, exists in cells. However, the velocity of the previously cloned myosin XI (XI) was about 20 μm s, one-third of the cytoplasmic streaming velocity in Recently, the genome sequence of has been published, revealing that this alga has four myosin XI genes.

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Article Synopsis
  • Molecular evolution rates differ among species and can shape their evolutionary paths, as seen in the aquatic plant family Podostemaceae.
  • Researchers found two significant increases in mutation rates in this family: one when it first evolved and another during the rise of its most diverse subfamily, Podostemoideae.
  • These elevated mutation rates featured a bias towards the AT base pair, likely influenced by UV light exposure and adaptations to their unique river habitats, while DNA-repair genes showed positive selection that may relate to changes in plant structure.
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Merkel cell polyomavirus (MCPyV) is the causative agent of an aggressive skin tumor, Merkel cell carcinoma. The viral genome is integrated into the tumor genome and harbors nonsense mutations in the helicase domain of large T antigen. However, the molecular mechanisms by which the viral genome gains the tumor-specific mutations remain to be elucidated.

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Complete chloroplast genome sequence of a moss, Takakia lepidozioides (Takakiopsida) is reported. The largest collection of genes in mosses and the intensive RNA editing were discussed from evolutionary perspectives. We assembled the entire plastid genome sequence of Takakia lepidozioides (Takakiopsida), emerging from the first phylogenetic split among extant mosses.

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Hyperdiverse tropical rainforests, such as the aseasonal forests in Southeast Asia, are supported by high annual rainfall. Its canopy is dominated by the species-rich tree family of Dipterocarpaceae (Asian dipterocarps), which has both ecological (e.g.

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Despite their key phylogenetic position and their unique biology, hornworts have been widely overlooked. Until recently there was no hornwort model species amenable to systematic experimental investigation. Anthoceros agrestis has been proposed as the model species to study hornwort biology.

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Some sea slugs sequester chloroplasts from algal food in their intestinal cells and photosynthesize for months. This phenomenon, kleptoplasty, poses a question of how the chloroplast retains its activity without the algal nucleus. There have been debates on the horizontal transfer of algal genes to the animal nucleus.

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Parasitic plants form a specialized organ, a haustorium, to invade host tissues and acquire water and nutrients. To understand the molecular mechanism of haustorium development, we performed a forward genetics screening to isolate mutants exhibiting haustorial defects in the model parasitic plant We isolated two mutants that show prolonged and sometimes aberrant meristematic activity in the haustorium apex, resulting in severe defects on host invasion. Whole-genome sequencing revealed that the two mutants respectively have point mutations in homologs of () and (), signaling components in response to the gaseous phytohormone ethylene.

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Samia ricini, a gigantic saturniid moth, has the potential to be a novel lepidopteran model species. Samia ricini is far more resistant to diseases than the current model species Bombyx mori, and therefore can be more easily reared. In addition, genetic resources available for S.

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Epigenetic DNA base methylation plays important roles in gene expression regulation. We here describe a gene expression regulation network consisting of many DNA methyltransferases each frequently changing its target sequence-specificity. Our object , a bacterium responsible for most incidence of stomach cancer, carries a large and variable repertoire of sequence-specific DNA methyltransferases.

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Background: Many long noncoding RNAs (lncRNAs) have important roles in biological processes. The lncRNA HULC was found to be upregulated in human hepatoma tissues. HULC is thought to be involved in multiple steps of hepatoma development and progression; however, the relationship between HULC and hepatitis C virus (HCV) infection, which is a leading cause of hepatoma, remains unclear.

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