Parmales (Bolidophyceae) is a minor eukaryotic phytoplankton group, sister to diatoms, which exists as two distinct forms of unicellular organisms: silicified cells and naked flagellates. Since their ...discovery, many field studies on Parmales have been performed; however, their global distribution has not yet been examined in detail. We herein compiled more than 3,000 marine DNA metabarcoding datasets targeting the V4 region of the 18S rRNA gene from the EukBank database. By linking this large dataset with the latest morphological and genetic information, we provide updated estimates on the diversity and distribution of Parmales in the global ocean at a fine taxonomic resolution. Parmalean amplicon sequence variants (ASVs) were detected in nearly 90% of the samples analyzed. However, the relative abundance of parmaleans in the eukaryotic community was less than 0.2% on average, and the estimated true richness of parmalean ASVs was approximately 316 ASVs, confirming their low abundance and diversity. A phylogenetic analysis divided these algae into four clades, and three known morphotypes of silicified cells were classified into three different clades. The abundance of Parmales is generally high in the poles and decreases towards the tropics, and individual clades/subclades show further distinctions in their distribution. Collectively, the present results suggest clade/subclade-specific adaptation to different ecological niches.
The order Parmales (class Bolidophyceae) is a minor group of pico-sized eukaryotic marine phytoplankton that contains species with cells surrounded by silica plates. Previous studies revealed that ...Parmales is a member of ochrophytes and sister to diatoms (phylum Bacillariophyta), the most successful phytoplankton group in the modern ocean. Therefore, parmalean genomes can serve as a reference to elucidate both the evolutionary events that differentiated these two lineages and the genomic basis for the ecological success of diatoms vs. the more cryptic lifestyle of parmaleans. Here, we compare the genomes of eight parmaleans and five diatoms to explore their physiological and evolutionary differences. Parmaleans are predicted to be phago-mixotrophs. By contrast, diatoms have lost genes related to phagocytosis, indicating the ecological specialization from phago-mixotrophy to photoautotrophy in their early evolution. Furthermore, diatoms show significant enrichment in gene sets involved in nutrient uptake and metabolism, including iron and silica, in comparison with parmaleans. Overall, our results suggest a strong evolutionary link between the loss of phago-mixotrophy and specialization to a silicified photoautotrophic life stage early in diatom evolution after diverging from the Parmales lineage.
Viruses have long been viewed as entities possessing extremely limited metabolic capacities. Over the last decade, however, this view has been challenged, as metabolic genes have been identified in ...viruses possessing large genomes and virions-the synthesis of which is energetically demanding. Here, we unveil peculiar phenotypic and genomic features of
virus RF01 (PkV RF01), a giant virus of the
family. We found that this virus encodes an unprecedented number of proteins involved in energy metabolism, such as all four succinate dehydrogenase (SDH) subunits (A-D) as well as key enzymes in the
-oxidation pathway. The
gene was transcribed upon infection, indicating that the viral SDH is actively used by the virus- potentially to modulate its host's energy metabolism. We detected orthologous
and
genes in numerous genome fragments from uncultivated marine
viruses, which suggests that the viral SDH is widespread in oceans. PkV RF01 was less virulent compared with other cultured prymnesioviruses, a phenomenon possibly linked to the metabolic capacity of this virus and suggestive of relatively long co-evolution with its hosts. It also has a unique morphology, compared to other characterized viruses in the
family. Finally, we found that PkV RF01 is the only alga-infecting
virus encoding two aminoacyl-tRNA synthetases and enzymes corresponding to an entire base-excision repair pathway, as seen in heterotroph-infecting
These
encoded-enzymes were found to be monophyletic and branching at the root of the eukaryotic tree of life. This placement suggests that the last common ancestor of
was endowed with a large, complex genome prior to the divergence of known extant eukaryotes.
Viruses on Earth are tremendously diverse in terms of morphology, functionality, and genomic composition. Over the last decade, the conceptual gap separating viruses and cellular life has tightened because of the detection of metabolic genes in viral genomes that express complex virus phenotypes upon infection. Here, we describe
virus RF01, a large alga-infecting virus with a unique morphology, an atypical infection profile, and an unprecedented number of genes involved in energy metabolism (such as the tricarboxylic (TCA) cycle and the
-oxidation pathway). Moreover, we show that the gene corresponding to one of these enzymes (the succinate dehydrogenase subunit A) is transcribed during infection and is widespread among marine viruses. This discovery provides evidence that a virus has the potential to actively regulate energy metabolism with its own gene.
The Department of Dentistry and Oral Surgery at Yukoukai Hospital was established in April 1980. As of December 31, 1985, the total number of inpatients treated was 587 and that of outpatients 17, ...975. These numbers increased year by year. We report here some clinical and statistical observations on our inpatients. The incidence of diseases was as follows: trauma: 50.0%, inflammatory diseases: 33.0%, cysts: 11.8%, tumors: 1. 1%, diseases of salivary glands: 0.6%, diseases of temporomandibular joint: 0.5%, and others: 2.9%. As can be seen, trauma and inflammatory diseases accounted for a vast majority of the diseases of inpatients. Emergency hospitalization was necessary for, 74.8% of the inpatients, 41.0% of whom were hospitalized outside regular hours (i.e., at night or on holidays).
Chemically driven self-propulsion of soft matter is useful for various applications because it can move toward a desired location, without external power fields, in response to chemical signals in ...environmental media. We have developed a suitable steering mechanism to maintain the orientation of self-propelled droplets loaded with surfactant in fluidic environments. A spatial gradient of alkaline-earth metal ions induces directional sensing. These metal ions can be arranged in descending order of directional sensing as Ba2+ ∼ Sr2+ > Ca2+ > Mg2+. On the other hand, the affinity between metal ions and di-(2-ethylhexyl)phosphoric acid (DEHPA) decreases in the order as Ca2+ > Ba2+ > Sr2+ > Mg2+. To clarify the difference between the order of directional sensing and that of affinity, we investigated the effect of metal ions on the driving force to create asymmetric convection. We found that changes in the interfacial tension under nonequilibrium conditions play an important role in directional sensing.
In Japan, freeze-dried live attenuated Oka-strain varicella-zoster virus vaccine, VVL (BIKEN), is available for adults aged ≥50 years to prevent herpes zoster (HZ). Although an increase in the ...antibody titer and cellular immune response has been demonstrated following vaccination with VVL (BIKEN), to date, no clinical studies have shown that the vaccine decreases the incidence of HZ and postherpetic neuralgia (PHN). This study investigated the incidence of HZ and PHN among adults aged ≥50 years who received a single dose of VVL (BIKEN) to prevent HZ.
This retrospective cohort study investigated the incidence of HZ and PHN among adults aged ≥50 years who received a single dose of VVL (BIKEN) at a large hospital and affiliated clinics in Japan. A dispensing database and electronic medical records were used to identify vaccine recipients and cases of HZ and PHN. The end date of the follow-up period and the reason to end the follow-up were defined to avoid underestimating the incidence. The analysis was stratified according to age, sex, immunocompromising conditions, and use of immunosuppressant therapy. Vaccine effectiveness was estimated using published estimates of the incidence of HZ and PHN in the unvaccinated population in Japan.
A total of 1175 patients were enrolled in the study. During a median follow-up period of 3.36 years, HZ was diagnosed in 27 participants (15 men 2.8% and 12 women 1.9%). The incidence of HZ among VVL (BIKEN) recipients was 7.67/1000 person-years. The incidence of PHN was 0.82/1000 person-years. The vaccine effectiveness was estimated as 27.8% 95% confidence interval (CI), −29.8 to 63.9% and 73.8% 95% CI, 38.6–100% against HZ and PHN, respectively.
The VVL (BIKEN) had limited effectiveness at preventing HZ, but relatively good effectiveness at preventing PHN. VVL (BIKEN) might have a role as an affordable alternative.
Mitochondria are dynamic organelles, and their fusion and fission regulate cellular signaling, development, and mitochondrial homeostasis, including mitochondrial DNA (mtDNA) distribution. Cardiac ...myocytes have a specialized cytoplasmic structure where large mitochondria are aligned into tightly packed myofibril bundles; however, recent studies have revealed that mitochondrial dynamics also plays an important role in the formation and maintenance of cardiomyocytes. Here, we precisely analyzed the role of mitochondrial fission in vivo. The mitochondrial fission GTPase, Drp1, is highly expressed in the developing neonatal heart, and muscle-specific Drp1 knockout (Drp1-KO) mice showed neonatal lethality due to dilated cardiomyopathy. The Drp1 ablation in heart and primary cultured cardiomyocytes resulted in severe mtDNA nucleoid clustering and led to mosaic deficiency of mitochondrial respiration. The functional and structural alteration of mitochondria also led to immature myofibril assembly and defective cardiomyocyte hypertrophy. Thus, the dynamics of mtDNA nucleoids regulated by mitochondrial fission is required for neonatal cardiomyocyte development by promoting homogeneous distribution of active mitochondria throughout the cardiomyocytes.
The filamentous fungus
Aspergillus fumigatus
is the most important pathogenic fungus among
Aspergillus
species associated with aspergillosis.
A. fumigatus
is exposed to diverse environmental stresses ...in the hosts during infection such as an excess of essential metal copper. To gain further insights into copper homeostasis, we generated an
A. fumigatus
laboratory evolved strain with increased fitness in copper stress, and identified the mutation in a Zn
2
-Cys
6
type transcription factor
clcA
. We examined the role of
clcA
using the evolved and
∆clcA
strains. The
∆clcA
strain exhibited defective growth on minimal medium, PDA and copper-repleted medium, and defective conidiogenesis and conidial pigmentation. We found that
clcA
was required for the expressions of genes involved in conidiogenesis, conidial pigmentation, and transporters
cdr1B
and
mfsB
related to azole resistance.
clcA
was dispensable for the virulence in silkworm infection model. We report here that
clcA
plays an important role in hyphal growth, conidiogenesis, and copper adaptation.
PDF
