Biology subjects

Lee, S.

Publications and source records attributed to Lee, S..

At least 631 records · Page 35Linked to original sources

bioRxiv2020

Analysis of circulating-microRNA expression in lactating Holstein cows under summer heat stress

Korean peninsular weather is rapidly becoming subtropical due to global warming. In summer 2018, South Korea experienced the highest temperatures since the meteorological observations recorded in 1907. Heat stress has a negative effect on Holstein cows, the most popular breed of dairy cattle in South Korea, which is susceptible to heat. To examine physiological changes in dairy cows under heat stress conditions, we analyzed the profiles circulating microRNAs isolated from whole blood samples collected under heat stress and non-heat stress conditions using small RNA sequencing. We compared the expression profiles in lactating cows under heat stress and non-heat stress conditions to understand the regulation of biological processes in heat-stressed cows. Moreover, we measured several heat stress indicators, such as rectal temperature, milk yield, average daily gain, and progesterone concentration. All these assessments showed that pregnant cows were more susceptible to heat stress than non-pregnant cows. Particularly, progesterone concentrations known to have maternal warming effects were at similar levels in non-pregnant cows but significantly increased in pregnant cows under heat stress conditions. The differentially expressed miRNAs and their putative target genes were analyzed in pregnant cows. Interestingly, we found that differentially expressed miRNAs (bta-miR-146b, bta-miR-20b, bta-miR-29d-3p, bta-miR-1246) specifically targeted progesterone biosynthesis (StAR) and the function of corpus luteum-related genes (CCL11, XCL), suggesting that pregnant cows with elevated progesterone concentrations are more susceptible to heat stress. In addition, we found the differential expression of 11 miRNAs (bta-miR-19a, bta-miR-19b, bta-miR-30a-5p, and several from the bta-miR-2284 family) in both pregnant and non-pregnant cows under heat stress conditions. In target gene prediction and gene set enrichment analysis, these miRNAs were found to be associated with the cytoskeleton, cell junction, vasculogenesis, cell proliferation, ATP synthesis, oxidative stress, and immune responses involved in heat response. These miRNAs can be used as potential biomarkers for heat stress.

genomics↗

bioRxiv2020

Cropping systems that improve richness convey increased resistance and resilience to fungal, but not prokaryote, communities.

Crop harvest followed by a fallow period can act as a disturbance on soil microbial communities. Cropping systems intended to improve alpha-diversity of communities may also confer increased compositional stability during succeeding growing seasons. Over a single growing season in a long-term (18 year) agricultural field experiment incorporating conventional (CON), conservation (CA), organic (ORG) and integrated (INT) cropping systems, temporal changes in prokaryote, fungal and arbuscular mycorrhizal fungi (AMF) communities were investigated overwinter, during crop growth and at harvest. While certain prokaryote phyla were influenced by cropping system (e.g. Acidobacteria), the community as a whole was primarily driven by temporal changes over the growing season as distinct overwinter and crop-associated communities, with the same trend observed regardless of cropping system. Species- rich prokaryote communities were most stable over the growing season. Cropping system exerted a greater effect on fungal communities, with alpha-diversity highest and temporal changes most stable under CA. CON was particularly detrimental for alpha-diversity in AMF communities, with AMF alpha-diversity and stability improved under all other cropping systems. Practices that promoted alpha-diversity tended to also increase the similarity and temporal stability of soil fungal (and AMF) communities during a growing season, while prokaryote communities were largely insensitive to management.

microbiology↗

bioRxiv2020

Developmental differentiation in a cytoplasm-dwelling obligate intracellular bacterium

Orientia tsutsugamushi (Ot) is an obligate intracellular bacterium in the family Rickettsiaceae that causes scrub typhus, a severe mite-borne human disease. Its mechanism of cell exit is unusual amongst Rickettsiaceae, as Ot buds off the surface of infected cells enveloped in plasma membrane. Here, we show that Ot bacteria that have budded out of host cells are in a distinct developmental stage compared with intracellular bacteria. We refer to these two stages as intracellular and extracellular bacteria (IB and EB, respectively). These two forms differ in physical properties: IB is elongated, and EB is round. Additionally, IB has higher levels of peptidoglycan and is physically robust compared with EB. The two bacterial forms differentially express proteins involved in bacterial physiology and host-pathogen interactions, specifically those involved in bacterial dormancy and stress response, secreted bacterial effectors, and outer membrane autotransporter proteins ScaA and ScaC. Whilst both populations are infectious, entry of IB Ot is sensitive to inhibitors of both clathrin-mediated endocytosis and macropinocytosis, whereas entry of EB Ot is only sensitive to a macropinocytosis inhibitor. Our identification and detailed characterization of two developmental forms of Ot significantly advances our understanding of the intracellular lifecycle of an important human pathogen. Author SummaryOrientia tsutsugamushi (Ot) is a bacterial pathogen that causes scrub typhus, a mite-transmitted human disease. This illness is traditionally known to be endemic in the Asia-Pacific, but recent reports of Orientia-like organisms from the Middle East, Africa, and Latin America suggest that it may be globally distributed. Scrub typhus is associated with high mortality if not treated promptly with appropriate antibiotics. Ot is a highly specialized bacterium that can only replicate within living cells, either within the mite vector or in mammalian or human hosts. Ot exits infected cells using a unique mechanism that involves budding off the surface of infected cells. We have discovered that this unusual aspect of its lifecycle involves the bacteria themselves differentiating into a distinct growth form. Different growth forms have not been described in other members of the family Rickettsiaceae, and no other family members have been shown to bud out of host cells in a manner similar to Ot. We find that the two forms of Ot, which we refer to as intracellular and extracellular bacteria (IB and EB respectively), differ in physical properties and protein expression and infect cells through different mechanisms. The identification of structurally and functionally distinct forms of Ot elucidates a vital aspect of this pathogens intracellular life cycle. The two forms are likely to have different antibiotic susceptibilities, therefore our findings may advance the development of novel interventions aimed at inhibiting Ot growth in scrub typhus patients.

microbiology↗

bioRxiv2020

ThiL is a valid antibacterial target that is essential for both thiamine biosynthesis and salvage pathway in Pseudomonas aeruginosa

Thiamine pyrophosphate (TPP) is an essential cofactor for various pivotal cellular processes in all living organisms, including bacteria. As thiamine biosynthesis occurs in bacteria but not humans, bacterial thiamine biosynthesis is an attractive target for antibiotic development. Among enzymes in the thiamine biosynthetic pathway, thiamine monophosphate kinase (ThiL) catalyzes the final step of the pathway, phosphorylating thiamine monophosphate (TMP) to produce TPP. In this work, we extensively investigated ThiL in Pseudomonas aeruginosa, a major pathogen of hospital-acquired infections. We demonstrated that thiL deletion abolishes not only thiamine biosynthesis but also thiamine salvage capability, showing growth defects of the {Delta}thiL mutant even in the presence of thiamine derivatives except TPP. Most importantly, the pathogenesis of the {Delta}thiL mutant was markedly attenuated compared to wild-type bacteria, with lower inflammatory cytokine induction and 103~104 times decreased bacterial load in an in vivo infection model where the intracellular TPP level is in the submicromolar range. In order to validate P. aeruginosa ThiL (PaThiL) as a new drug target, we further characterized its biochemical properties determining a Vmax of 4.0{+/-}0.2 nomol{middle dot}min-1 and KM values of 111{+/-}8 and 8.0{+/-}3.5M for ATP and TMP, respectively. A subsequent in vitro small molecule screening identified PaThiL inhibitors including WAY213613 that is a noncompetitive inhibitor with a Ki value of 13.4{+/-}2.3 M and a potential antibacterial activity against P. aeruginosa. This study proved that PaThiL is a new drug target against P. aeruginosa providing comprehensive biological and biochemical data that could facilitate to develop a new repertoire of antibiotics.

microbiology↗

bioRxiv2020

SPAs promote thermomorphogenesis via regulating the phyB-PIF4 module in Arabidopsis

High ambient temperature due to global warming has a profound influence on plant growth and development at all stages of life cycle. Plant response to high ambient temperature termed thermomorphogenesis is characterized by hypocotyl and petiole elongation, and hyponastic growth at seedling stage. However, the molecular mechanism of thermomorphogenesis is still rudimentary. Here, we show that a set of four SUPPRESSOR OF PHYA-105 (SPA) genes are required for thermomorphogenesis. Consistently, SPAs are necessary for global gene expression changes in response to high ambient temperature. SPA1 level is unaffected, while the thermosensor phyB is stabilized in the spaQ mutant at high ambient temperature. Furthermore, in the absence of four SPA genes, the pivotal transcription factor PIF4 fails to accumulate, indicating a role of SPAs in regulating the phyB-PIF4 module at high ambient temperature. SPA1 directly phosphorylates PIF4 in vitro, and a mutant SPA1 affecting the kinase activity fails to rescue the PIF4 level as well as the thermo-insensitive phenotype of spaQ, suggesting that the SPA1 kinase activity is necessary for thermomorphogenesis. Taken together, these data suggest that SPAs integrate light and temperature signaling via fine tuning the phyB-PIF4 module.

plant biology↗

bioRxiv2020

Genome-Wide Identification and Characterization of MLO Gene Family in Octoploid Strawberry

Powdery mildew (PM) caused by Podosphaera aphanis is a major fungal disease in cultivated strawberry. Mildew Resistance Locus O (MLO) is a gene family described for having conserved seven-transmembrane domains. Induced loss-of-function in specific MLO genes can confer durable and broad resistance against PM pathogens. However, the underlying biological role of MLO genes in strawberry is still unknown. In the present study, the genomic structure of MLO genes were characterized in both diploid (Fragaria vesca) and octoploid strawberry (Fragaria xananassa), and the potential sources of MLO-mediated susceptibility were identified. Twenty MLO-like sequences were identified in F. vesca, with sixty-eight in F. xananassa. Phylogenetic analysis divides strawberry MLO genes into eight different clades, in which three FveMLO and ten FaMLO genes were grouped together with the functionally known MLO susceptibility. Out of ten FaMLO genes, FaMLO17-2 and FaMLO17-3 showed the highest similarity to the known susceptibility MLO proteins. Gene expression analysis of FaMLO genes was conducted using a multi-parental segregating population. Three expression quantitative trait loci (eQTL) were substantially associated with MLO transcript levels in mature fruits, suggesting discrete genetic control of susceptibility. These results are a critical first step in understanding allele function of MLO genes, and are necessary for further genetic studies of PM resistance in cultivated strawberry.

plant biology↗

bioRxiv2019

Twelve Platinum-Standard Reference Genomes Sequences (PSRefSeq) that complete the full range of genetic diversity of Asian rice

As the human population grows from 7.8 billion to 10 billion over the next 30 years, breeders must do everything possible to create crops that are highly productive and nutritious, while simultaneously having less of an environmental footprint. Rice will play a critical role in meeting this demand and thus, knowledge of the full repertoire of genetic diversity that exists in germplasm banks across the globe is required. To meet this demand, we describe the generation, validation and preliminary analyses of transposable element and long-range structural variation content of 12 near-gap-free reference genome sequences (RefSeqs) from representatives of 12 of 15 subpopulations of cultivated rice. When combined with 4 existing RefSeqs, that represent the 3 remaining rice subpopulations and the largest admixed population, this collection of 16 Platinum Standard RefSeqs (PSRefSeq) can be used as a pan-genome template to map resequencing data to detect virtually all standing natural variation that exists in the pan-cultivated rice genome.

genomics↗

bioRxiv2019

Large scale analyses of genotype-phenotype relationships of glycine decarboxylase mutations and neurological disease severity.

Monogenetic diseases provide unique opportunity for studying complex, clinical states that underlie neurological severity. Loss of glycine decarboxylase (GLDC) can severely impact neurological development as seen in non-ketotic hyperglycinemia (NKH). NKH is a neuro-metabolic disorder lacking quantitative predictors of disease states. It is characterized by elevation of glycine, seizures and failure to thrive, but glycine reduction often fails to confer neurological benefit, suggesting need for alternate tools to distinguish severe from attenuated disease. A major challenge has been that there are 255 unique disease-causing missense mutations in GLDC, of which 206 remain entirely uncharacterized. Here we report a Multiparametric Mutation Score (MMS) developed by combining in silico predictions of stability, evolutionary conservation and protein interaction models and suitable to assess 251 of 255 mutations. In addition, we created a quantitative scale of clinical disease severity comprising of four major disease domains (seizure, cognitive failure, muscular and motor control and brain-malformation) to comprehensively score patient symptoms identified in 131 clinical reports published over the last 15 years. The resulting patient Clinical Outcomes Scores (COS) were used to optimize the MMS for biological and clinical relevance and yield a patient Weighted Multiparametric Mutation Score (WMMS) that separates severe from attenuated neurological disease (p < 3.5e-5). Our study provides understanding for developing quantitative tools to predict clinical severity of neurological disease and a clinical scale that advances monitoring disease progression needed to evaluate new treatments for NKH.

bioinformatics↗

bioRxiv2019

The Kinase Chemogenomic Set (KCGS): An open science resource for kinase vulnerability identification

We describe the assembly and annotation of a chemogenomic set of protein kinase inhibitors as an open science resource for studying kinase biology. The set only includes inhibitors that show potent kinase inhibition and a narrow spectrum of activity when screened across a large panel of kinase biochemical assays. Currently, the set contains 187 inhibitors that cover 215 human kinases. The kinase chemogenomic set (KCGS) is the most highly annotated set of selective kinase inhibitors available to researchers for use in cell-based screens.

cell biology↗

bioRxiv2019

A novel IKK- and proteasome-independent mechanism of RelA activation triggers senescence associated secretome via transcriptional repression of NFKBIA

The I{kappa}B kinase (IKK) - NF-{kappa}B pathway is activated as part of the DNA damage response and controls both resistance to apoptosis and inflammation. How these different functions are achieved remained unknown. We demonstrate here that DNA double strand breaks elicit two subsequent phases of NF-{kappa}B activation in vivo and in vitro, which are mechanistically and functionally distinct. RNA-sequencing reveals that the first phase controls anti-apoptotic gene expression, while the second drives expression of senescence-associated secretory phenotype (SASP) genes. The first, rapidly activated phase is driven by the ATM-PARP1-TRAF6-IKK cascade, which triggers proteasomal destruction of I{kappa}B and is terminated through I{kappa}B (NFKBIA) re-expression. The second phase is activated days later in senescent cells but is independent of IKK and the proteasome. An altered phosphorylation status of p65, in part driven by GSK3{beta}, results in transcriptional silencing of NFKBIA and IKK-independent, constitutive activation of NF-{kappa}B in senescence. Collectively, our study reveals a novel physiological mechanism of NF-{kappa}B activation with important implications for genotoxic cancer treatment.

cell biology↗

bioRxiv2019

Design of DNA Origami Diamond Photonic Crystals

Self-assembled photonic crystals have proven to be a fascinating class of photonic materials for non-absorbing structural colorizations over large areas and in diverse relevant applications, including tools for on-chip spectrometers and biosensors, platforms for reflective displays, and templates for energy devices. The most prevalent building blocks for the self-assembly of photonic crystals are spherical colloids and block copolymers (BCPs) due to the generic appeal of these materials, which can be crafted into large-area 3D lattices. However, due to the intrinsic limitations of these structures, these two building blocks are difficult to assemble into a direct rod-connected diamond lattice, which is considered to be a champion photonic crystal. Here, we present a DNA origami-route for a direct rod-connected diamond photonic crystal exhibiting a complete photonic bandgap (PBG) in the visible regime. Using a combination of electromagnetic, phononic, and mechanical numerical analyses, we identify (i) the structural constraints of the 50 megadalton-scale giant DNA origami building blocks that could self-assemble into a direct rod-connected diamond lattice with high accuracy, and (ii) the elastic moduli that are essentials for maintaining lattice integrity in a buffer solution. A solution molding process could enable the transformation of the as-assembled DNA origami lattice into a porous silicon- or germanium-coated composite crystal with enhanced refractive index contrast, in that a champion relative bandwidth for the photonic bandgap (i.e., 0.29) could become possible even for a relatively low volume fraction (i.e., 16 vol%).

synthetic biology↗

bioRxiv2019

Measurements of 3-D morphology of individual red blood cells upon localized photothermal effects using gold nanorods

We investigated the in-situ photothermal response of human red blood cells (RBCs) by combining photothermal heat generation and 3D quantitative phase imaging techniques. Gold-nanorod-coated substrates were excited using near-infrared light to generate local heat to RBCs, and response was measured by imaging 3-D refractive index tomograms of cells under various near infrared (NIR) excitation conditions. On photothermal treatment, cell morphology changed from discoid to crescent shapes, cell volume and dry mass decreased, and hemoglobin concentration increased. We also investigated the irreversible deformation of RBCs when multiple intense excitation shocks are applied. These results provide a new understanding of thermodynamic aspects of cell biology and hematology. O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY

biophysics↗

bioRxiv2019

Cleft lip and cleft palate (CL/P) in Esrp1 KO mice is associated with alterations in Wnt signaling and epithelial-mesenchymal crosstalk

Cleft lip is one of the most highly prevalent birth defects in human patients. However, there remain a limited number of mouse models of cleft lip and thus much work is needed to further characterize genes and mechanisms that lead to this disorder. It is well established that crosstalk between epithelial and mesenchymal cells underlies formation of the face and palate, yet the basic molecular events mediating this crosstalk are still poorly understood. We previously demonstrated that mice with ablation of the epithelial-specific splicing factor Esrp1 have fully penetrant bilateral CL/P. In this study we further investigated the mechanisms by which ablation of Esrp1 leads to cleft lip as well as cleft palate. These studies included a detailed analysis of the changes in splicing and total gene expression in embryonic ectoderm during formation of the face as well as gene expression changes in adjacent mesenchyme. We identified altered expression in components of pathways previously implicated in cleft lip and/or palate, including numerous components of the Wnt signaling pathway. These findings illustrate that maintenance of an Esrp1 regulated epithelial splicing program is essential for face development through regulation of key signaling pathways.

developmental biology↗

bioRxiv2019

Serial assessment of iron in the motor cortex in limb-onset Amyotrophic Lateral Sclerosis using Quantitative Susceptibility Mapping

ObjectiveDysregulation of iron in the cerebral motor areas has been hypothesized to occur in individuals with Amyotrophic Lateral Sclerosis (ALS). There is still limited knowledge regarding iron dysregulation in the progression of ALS pathology. Our objectives were to use magnetic resonance based Quantitative Susceptibility Mapping (QSM) to investigate the association between iron dysregulation in the motor cortex and clinical manifestations in patients with limb-onset ALS, and to examine changes in the iron concentration in the motor cortex in these patients over a six-month period. MethodsIron concentration was investigated using magnetic resonance based -QSM in the primary motor cortex and the pre-motor area in thirteen limb-onset ALS patients (including five lumbar onset, six cervical onset and two flail arm patients), and eleven age and sex-matched healthy controls. Nine ALS patients underwent follow-up scans at six months. ResultsSignificantly increased QSM was observed in the left posterior primary motor area (p = 0.02, Cohens d = 0.9) and right anterior primary motor area (p = 0.02, Cohens d = 0.92) in all individuals with limb-onset ALS compared to healthy controls. Increased QSM was observed in the primary motor and pre-motor area at baseline in patients with lumbar onset ALS patients, but not cervical limb-onset ALS patients, compared to healthy controls. No significant change in QSM was observed at the six-month follow-up scans in the ALS patients. ConclusionsThe findings suggest that iron dysregulation can be detected in the motor cortex in limb-onset ALS, which does not appreciably change over a further 6 months. Individuals with lumbar onset ALS appear to be more susceptible to motor cortex iron dysregulation compared to the individuals with cervical onset ALS. Importantly, this study highlights the potential use of QSM as a radiological indicator in disease diagnosis, and in clinical trials in limb-onset ALS and its subtypes. HighlightsO_LISerial measurement of QSM in the motor cortex in limb-onset ALS was performed C_LIO_LIQSM changes in the motor cortex in ALS sub-groups were investigated C_LIO_LIHigher QSM was observed in the motor cortex in Lumbar ALS relative to controls C_LIO_LIQSM is sensitive to iron dysregulation in the motor cortex in limb-onset ALS C_LI

neuroscience↗

bioRxiv2019

Geometric principles underlying the proliferation of a model cell system

Wall deficient variants of many bacteria, called L-forms, divide by a simple mechanism that does not depend on the complex FtsZ-based cell division machine. We have used microfluidic systems to probe the growth, chromosome cycle and division mechanism of Bacillus subtilis L-forms. The results show that forcing cells into a narrow linear configuration greatly improves the efficiency of cell growth and chromosome segregation. This reinforces the view that L-form division is driven by an excess accumulation of surface area over volume. Cell geometry was also found to play a dominant role in controlling the relative positions and movement of segregating chromosomes. The presence of the nucleoid appears to influence division both via a cell volume effect and by nucleoid occlusion, even in the absence of the FtsZ machine. Overall, our results emphasise the importance of geometric effects for a range of critical cell functions and are of relevance for efforts to develop artificial or minimal cell systems.

microbiology↗

bioRxiv2019

Hepatocytic Prominin-1 protects liver fibrosis by stabilizing the SMAD7 protein

Background and AimsProminin-1 (PROM1) is known to be upregulated in hepatocytic progenitor cells (HPCs) and cholangiocytes of fibrotic livers. To understand the function of upregulated PROM1 during liver fibrosis, we analyzed liver fibrosis from global and liver-specific Prom1 knockout mice and investigated the molecular mechanism of how Prom1 protects the liver against liver fibrosis. MethodsWe analyzed PROM1 expression from human liver with mild and severe liver fibrosis (n=4-9). Liver fibrosis was induced by carbon tetrachloride (CCl4) treatment and bile duct ligation (BDL) from wild type and global and liver-specific knockout mice (n=3-13). The severity of liver fibrosis was determined by qRT-PCR, immunostaining and immunoblotting for fibrotic markers such as SMA, collagen. TGF{beta} signaling was also analyzed from fibrotic liver and primary hepatocytes of wild type and global and liver-specific knockout mice (n=3-5). Molecular interaction between PROM1 and SMAD7 was determined by endogenous and exogenous co-immunoprecipitation. ResultsPROM1 was found in the plasma membranes of both healthy and fibrotic hepatocytes and cholangiocytes. Global Prom1 knockout aggravated BDL- and CCl4-induced liver fibrosis. Prom1-/- hepatocytes showed increased TGF{beta} signaling due to reduced SMAD7 protein expression compared to that in wild-type hepatocytes. PROM1 prevented SMURF2-induced SMAD7 ubiquitination and degradation by interfering with the molecular association of SMAD7 with SMURF2. We also demonstrated that liver-specific Prom 1 knockout aggravated BDL-induced liver fibrosis due to reduced levels of SMAD7. ConclusionHepatocytic PROM1 stabilizes SMAD7, preventing TGF{beta} signaling. Thus, PROM1 is necessary for the negative regulation of TGF{beta} signaling during liver fibrosis.

cell biology↗

bioRxiv2019

Measuring three-dimensional dynamics of platelet activation using 3-D quantitative phase imaging

Platelets, or thrombocytes, are anucleated tiny blood cells with an indispensable contribution to the hemostatic properties of whole blood, detecting injured sites at the surface of blood vessels and forming blood clots. Here, we quantitatively and non-invasively investigated the morphological and biochemical alterations of individual platelets during activation in the absence of exogenous agents by employing 3-D quantitative phase imaging (QPI). By reconstructing 3-D refractive index (RI) tomograms of individual platelets, we investigated alterations in platelet activation before and after the administration of various platelet agonists. Our results showed that while the integrity of collagen-stimulated platelets was preserved despite the existence of a few degranulated platelets with developed pseudopods, platelets stimulated by thrombin or thrombin receptor-activating peptide (TRAP) exhibited significantly lower cellular concentration and dry mass than did resting platelets. Our work provides a means to systematically investigate drug-respondents of individual platelets in a label-free and quantitative manner, and open a new avenue to the study of the activation of platelets.\n\n\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=91 SRC=\"FIGDIR/small/827436v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (39K):\norg.highwire.dtl.DTLVardef@17fe91eorg.highwire.dtl.DTLVardef@a1b25dorg.highwire.dtl.DTLVardef@1c519d8org.highwire.dtl.DTLVardef@123b6dd_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2019

Comparative microbiomes of three species of laboratory-reared Periplaneta cockroaches

Cockroaches are the most primitive insects, and are often used as the basic insect model in many studies. Three species of Periplaneta cockroaches were raised in the laboratory for many generations under the same conditions. We conducted 16S rRNA-targeted high-throughput sequencing to evaluate the overall bacterial composition in the microbiomes of three species of cockroaches. The number of operational taxonomic units (OTUs) was not significantly different between the three cockroach species. With respect to the Shannon and Pielou indexes, the microbiome of Periplaneta americana presented higher values than that of either P. japonica or P. fulginosa. In terms of species composition, endosymbionts accounted for over half of all the bacterial species in P. japonica and P. fulginosa. The beta diversity analysis showed that P. japonica and P. fulginosa exhibit a similar microbiome composition, which is different from that of P. americana. However, we also identified that P. japonica and P. fulginosa are hosts to distinct bacterial species. Thus, although the composition of the microbiome may vary based on multiple conditions, it is possible to identify distinct compositions of the microbiome among the different Periplaneta cockroach species even when individuals are reared under the same conditions.\n\nImportanceCockroaches inhabit various habitats--which are known to be related to their microbiome--and exhibit different features depending on the species. It is expected that their microbiomes would vary according to species depending on these features. Cockroach microbiomes are known to vary based on the diet or environmental shifts. In this study, we compare the diversity of bacteria in the three cockroach species under conditions of reduced diet and environment shifts. This study can establish the basic microbiomes of three Periplaneta species and can be the basic data for cockroach research.

microbiology↗