Ubiquinone (UQ), the only known electron carrier in the mammalian electron transport chain (ETC), preferentially delivers electrons to the terminal electron acceptor oxygen (O2). In hypoxia, ubiquinol (UQH2) diverts these electrons onto fumarate instead. Here, we identify rhodoquinone (RQ), an electron carrier detected in mitochondria purified from certain mouse and human tissues that preferentially delivers electrons to fumarate through the reversal of succinate dehydrogenase, independent of environmental O2 levels. The RQ/fumarate ETC is strictly present in vivo and is undetectable in cultured mammalian cells. Using genetic and pharmacologic tools that reprogram the ETC from the UQ/O2 to the RQ/fumarate pathway, we establish that these distinct ETCs support unique programs of mitochondrial function and that RQ confers protection upon hypoxia exposure in vitro and in vivo. Thus, in discovering the presence of RQ in mammals, we unveil a tractable therapeutic strategy that exploits flexibility in the ETC to ameliorate hypoxia-related conditions.

• Klíčová slova
• electron transport chain, hypoxia, ischemia, metabolism, mitochondria, rhodoquinone,
• MeSH
• elektrony MeSH
• fumaráty metabolismus   MeSH
• hypoxie metabolismus   MeSH
• kyslík metabolismus   MeSH
• lidé MeSH
• mitochondrie * metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• sukcinátdehydrogenasa metabolismus   MeSH
• transport elektronů MeSH
• ubichinon * metabolismus   analogy a deriváty   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fumaráty MeSH
• kyslík MeSH
• rhodoquinone MeSH Prohlížeč
• sukcinátdehydrogenasa MeSH
• ubichinon * MeSH

The evolution of intracellular endosymbiosis marks a major transition in the biology of the host and endosymbiont. Yet, how adaptation manifests in the genomes of the participants remains relatively understudied. We investigated this question by sequencing the genomes of Tetrahymena utriculariae, a commensal of the aquatic carnivorous bladderwort Utricularia reflexa, and its intracellular algae, Micractinium tetrahymenae. We discovered an expansion in copy number and negative selection in a TLD domain-bearing gene family in the genome of T. utriculariae, identifying it as a candidate for being an adaptive response to oxidative stress resulting from the physiology of its endosymbionts. We found that the M. tetrahymenae genome is larger than those of other Micractinium and Chlorella and contains a greater number of rapidly expanding orthogroups. These were enriched for Gene Ontology terms relevant to the regulation of intracellular signal transduction and cellular responses to stress and stimulus. Single-exon tandem repeats were overrepresented in paralogs belonging to these rapidly expanding orthogroups, which implicates long terminal repeat retrotransposons (LTRs) as potential agents of adaptation. We additionally performed a comparative transcriptomic analysis of M. tetrahymenae in a free-living state and in endosymbiosis with T. utriculariae and discovered that the genes that are differentially expressed were enriched for pathways that evidence shifts in energy generation and storage and in cellular protection strategies. Together, our results elucidate the axes along which the participants must adapt in this young endosymbiosis and highlight evolutionary responses to stress as a shared trend.

• Klíčová slova
• LTR, ciliate, endosymbiosis, genome, green algae, stress, tandem gene duplications,
• MeSH
• biologická evoluce MeSH
• Chlorophyta genetika   MeSH
• fyziologická adaptace genetika   MeSH
• genom protozoální * MeSH
• hluchavkotvaré genetika   MeSH
• molekulární evoluce MeSH
• oxidační stres MeSH
• symbióza * MeSH
• Tetrahymena * genetika   MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Parasitism as a life strategy has independently evolved multiple times within the eukaryotic tree of life. Each lineage has developed mechanisms to invade hosts, exploit resources, and ensure replication, but our knowledge of survival mechanisms in many parasitic taxa remain extremely limited. One such group is the Myxozoa, which are obligate, dixenous cnidarians. Evidence suggests that myxozoans evolved from free-living ancestors to endoparasites around 600 million years ago and are likely one of the first metazoan parasites on Earth. Some myxozoans pose significant threats to farmed and wild fish populations, negatively impacting aquaculture and fish stocks; one such example is Sphaerospora molnari, which forms spores in the gills of common carp (Cyprinus carpio), disrupting gill epithelia and causing somatic and respiratory failure. Sphaerospora molnari undergoes sequential development in different organs of its host, with large numbers of morphologically distinct stages occurring in the blood, liver, and gills of carp. We hypothesize that these parasite life-stages differ in regards to their host exploitation, pathogenicity, and host immune evasion strategies and mechanisms. We performed stage-specific transcriptomic profiling to identify differentially expressed key functional gene groups that relate to these functions and provide a fundamental understanding of the mechanisms S. molnari uses to optimize its parasitic lifestyle. We aimed to identify genes that are likely related to parasite pathogenicity and host cell exploitation mechanisms, and we hypothesize that genes unique to S. molnari might be indicative of evolutionary innovations and specific adaptations to host environments. RESULTS: We used parasite isolation protocols and comparative transcriptomics to study early proliferative and spore-forming stages of S. molnari, unveiling variation in gene expression between each stage. We discovered several apparent innovations in the S. molnari transcriptome, including proteins that are likely to function in the uptake of previously unknown key nutrients, immune evasion factors that may contribute to long-term survival in hosts, and proteins that likely improve adhesion to host cells that may have arisen from horizontal gene transfer. Notably, we identified genes that are similar to known virulence factors in other parasitic organisms, particularly blood and intestinal parasites like Plasmodium, Trypanosoma, and Giardia. Many of these genes are absent in published cnidarian and myxozoan datasets and appear to be specific to S. molnari; they may therefore represent potential innovations enabling Sphaerospora to exploit the host's blood system. CONCLUSIONS: In order to address the threat posed by myxozoans to both cultured fish species and wild stocks, it is imperative to deepen our understanding of their genetics. Sphaerospora molnari offers an appealing model for stage-specific transcriptomic profiling and for identifying differentially expressed key functional gene groups related to parasite development. We identified genes that are thus far unique to S. molnari, which reveal their evolutionary novelty and likely role as adaptations to specific host niches. In addition, we describe the pathogenicity-associated genetic toolbox of S. molnari and discuss the implications of our discoveries for disease control by shedding light on specific targets for potential intervention strategies.

• Klíčová slova
• Sphaerospora molnari, Differential expression, Myxozoans, Pathogenicity related, Species specific genes,
• MeSH
• fyziologická adaptace genetika   MeSH
• interakce hostitele a parazita genetika   MeSH
• kapři parazitologie   MeSH
• Myxozoa * genetika   patogenita   fyziologie   MeSH
• nemoci ryb parazitologie   MeSH
• stadia vývoje genetika   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom * MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

In RNA interference (RNAi), long double-stranded RNA is cleaved by the Dicer endonuclease into small interfering RNAs (siRNAs), which guide degradation of complementary RNAs. While RNAi mediates antiviral innate immunity in plants and many invertebrates, vertebrates have adopted a sequence-independent response and their Dicer produces siRNAs inefficiently because it is adapted to process small hairpin microRNA precursors in the gene-regulating microRNA pathway. Mammalian endogenous RNAi is thus a rudimentary pathway of unclear significance. To investigate its antiviral potential, we modified the mouse Dicer locus to express a truncated variant (DicerΔHEL1) known to stimulate RNAi and we analyzed how DicerΔHEL1/wt mice respond to four RNA viruses: coxsackievirus B3 and encephalomyocarditis virus from Picornaviridae; tick-borne encephalitis virus from Flaviviridae; and lymphocytic choriomeningitis virus (LCMV) from Arenaviridae. Increased Dicer activity in DicerΔHEL1/wt mice did not elicit any antiviral effect, supporting an insignificant antiviral function of endogenous mammalian RNAi in vivo. However, we also observed that sufficiently high expression of DicerΔHEL1 suppressed LCMV in embryonic stem cells and in a transgenic mouse model. Altogether, mice with increased Dicer activity offer a new benchmark for identifying and studying viruses susceptible to mammalian RNAi in vivo.

In RNA interference (RNAi), the enzyme Dicer cuts long double-stranded RNA into small interfering RNAs that degrade matching RNAs. RNAi is a key antiviral defense in plants and invertebrates but vertebrates evolved a principally different antiviral defense. The authors genetically modified Dicer in mice to activate RNAi in mammals. These modified mice were tested against four RNA viruses but showed no significant antiviral response. However, further increased expression of modified Dicer did suppress one virus (lymphocytic choriomeningitis virus) in embryonic stem cells and in a transgenic mouse model, suggesting that some viruses might be sensitive to increased RNAi activity in mammals.

• MeSH
• DEAD-box RNA-helikasy genetika   metabolismus   MeSH
• malá interferující RNA genetika   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• přirozená imunita * genetika   MeSH
• ribonukleasa III * genetika   metabolismus   MeSH
• RNA interference * MeSH
• virus encefalomyokarditidy genetika   imunologie   MeSH
• virus lymfocytární choriomeningitidy imunologie   genetika   MeSH
• viry klíšťové encefalitidy genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DEAD-box RNA-helikasy MeSH
• Dicer1 protein, mouse MeSH Prohlížeč
• malá interferující RNA MeSH
• ribonukleasa III * MeSH

The classic plant growth-promoting phytohormone cytokinin has been identified and established as a mediator of pathogen resistance in different plant species. However, the resistance effect of structurally different cytokinins appears to vary and may regulate diverse mechanisms to establish resistance. Hence, we comparatively analysed the impact of six different adenine- and phenylurea-type cytokinins on the well-established pathosystem Nicotiana tabacum-Pseudomonas syringae. The efficiency of resistance effects was evaluated based on impacts on the host plant defence response by scoring infection symptoms and the direct impact on the pathogen by assessment of proliferation in planta. To identify common and cytokinin-specific components involved in resistance effects, transcriptome profiling and targeted metabolomics were conducted in leaves treated with the different cytokinins. We observed clearly different potentials of the tested cytokinins in either suppressing infection symptoms or pathogen proliferation. Gene regulation and metabolite analyses revealed cytokinin-type specific impacts on defence components, such as salicylic acid and related signalling, expression of PR proteins, and regulation of specialised metabolism. Cytokinins also strongly affected plant cell physiological parameters, such as a remarkable decrease in amino acid pools. Hence, this study provides comparative information on the efficiency of diverse cytokinins in mediating resistance in one well-studied pathosystem and insights into the specific regulation of resistance effects mediated by different cytokinin molecules. This is particularly relevant for studies on the function of cytokinins or other phytohormones and compounds interacting with cytokinin activities in the context of pathogen infections and other stress scenarios, considering the diverse cytokinins present in plants.

• MeSH
• cytokininy * metabolismus   MeSH
• listy rostlin mikrobiologie   metabolismus   genetika   MeSH
• nemoci rostlin * mikrobiologie   imunologie   genetika   MeSH
• odolnost vůči nemocem * genetika   MeSH
• Pseudomonas syringae * fyziologie   patogenita   MeSH
• regulace genové exprese u rostlin účinky léků   MeSH
• regulátory růstu rostlin metabolismus   MeSH
• tabák * mikrobiologie   genetika   imunologie   účinky léků   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cytokininy * MeSH
• regulátory růstu rostlin MeSH

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. Therefore, understanding the molecular regulatory mechanisms underlying the pathogenesis of DKD is imperative. In this study, we aimed to explore the molecular mechanisms of tubule region endothelial dysfunction in early DKD. Early-stage DKD model was established in 16-week-old female db/db mice for 16 weeks. Body weight, glucose level, and urine albumin-to-creatinine ratio (UACR) were measured. Hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining were performed to evaluate pathological lesions. RNA sequencing data of the kidneys and integrated publicly available single-cell and spatial transcriptome datasets were used to investigate the mechanism of endothelial dysfunction. There was a significant increase in body weight (p = 0.001), glucose levels (p=0.0008), and UACR (p=0.006) in db/db mice compared with db/m mice. H&E and PAS staining showed that vacuolar lesions and protein casts of tubules were the major histopathological changes observed in early-stage DKD mice. The apoptotic pathway in endothelial cells was notably activated in DKD, and Thbs1 was identified as the central gene involved in this apoptotic process. Deconvolution of the cell composition in the RNA sequencing data showed a decrease in the proportion of endothelial cells in the DKD mice. Further analysis of the activity and regulatory network of transcription factors showed that Creb1 was activated in both mouse and human early-stage DKD, suggesting that Creb1 activation may be involved in early kidney injury. The endothelial cell apoptotic pathway is activated in DKD, and the proportion of endothelial cells was reduced in the DKD mice, which is significantly associated with Thbs1. Keywords: Diabetic kidney disease, Endothelial dysfunction, RNA sequencing,Thbs1, Creb1.

• MeSH
• apoptóza MeSH
• diabetické nefropatie * patologie   metabolismus   patofyziologie   genetika   MeSH
• endoteliální buňky metabolismus   patologie   MeSH
• ledvinové kanálky patologie   metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• progrese nemoci * MeSH
• protein vázající element responzivní pro cyklický AMP metabolismus   genetika   MeSH
• thrombospondin 1 metabolismus   genetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protein vázající element responzivní pro cyklický AMP MeSH
• thrombospondin 1 MeSH

Potato (Solanum tuberosum L.) is one of the most important food crops globally and is especially vulnerable to heat stress. However, substantial knowledge gaps remain in our understanding of the developmental mechanisms associated with tuber responses to heat stress. This study used whole-plant physiology, transcriptomics, and phytohormone profiling to elucidate how heat stress affects potato tuber development. When plants were grown in projected future elevated temperature conditions, abscisic acid (ABA) levels decreased in leaf and tuber tissues, whereas rates of leaf carbon assimilation and stomatal conductance were not significantly affected compared to those plants grown in historical temperature conditions. While plants grown in projected future elevated temperature conditions initiated more tubers per plant on average, there was a 66% decrease in mature tubers at the final harvest compared to those plants grown in historical temperature conditions. We hypothesize that reduced tuber yields at elevated temperatures are not due to reduced tuber initiation, but due to impaired tuber filling. Transcriptomic analysis detected significant changes in the expression of genes related to ABA response, heat stress, and starch biosynthesis. The tuberization repressor genes SELF-PRUNING 5G (StSP5G) and CONSTANS-LIKE1 (StCOL1) were differentially expressed in tubers grown in elevated temperatures. Two additional known tuberization genes, IDENTITY OF TUBER 1 (StIT1) and TIMING OF CAB EXPRESSION 1 (StTOC1), displayed distinct expression patterns under elevated temperatures compared to historical temperature conditions but were not differentially expressed. This work highlights potential gene targets and key developmental stages associated with tuberization to develop potatoes with greater heat tolerance.

• MeSH
• hlízy rostlin * genetika   růst a vývoj   fyziologie   MeSH
• kyselina abscisová * metabolismus   MeSH
• listy rostlin genetika   fyziologie   MeSH
• reakce na tepelný šok genetika   MeSH
• regulace genové exprese u rostlin * MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rostlinné proteiny genetika   metabolismus   MeSH
• škrob metabolismus   MeSH
• Solanum tuberosum * genetika   fyziologie   růst a vývoj   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• teplota MeSH
• transkriptom genetika   MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kyselina abscisová * MeSH
• regulátory růstu rostlin MeSH
• rostlinné proteiny MeSH
• škrob MeSH

Pod dehiscence facilitates seed dispersal in wild legumes while indehiscence is a key domestication trait in cultivated ones. However, the evolutionary genetic mechanisms underlying its diversity are largely unclear. In this study, we compared transcriptomes of two warm-season (Glycine spp. and Phaseolus spp.) and two cool-season (Pisum spp. and Medicago ruthenica) legumes in analysis of dehiscent and indehiscent pod genotypes. Differentially expressed genes in AP2/ERF-like transcription factors and seven structural gene families, including lactoperoxidase, laccase, and cellulose synthase-interactive proteins, which are involved in secondary cell wall component accumulation, were identified to exert key roles in pod dehiscence variation. In accordance with this, higher lignin and cellulose contents were observed in pod secondary cell wall of dehiscent accessions of soybean and pea; however, the variation patterns of lignin polymers in soybean (accumulation) and pea (proportion) differed between dehiscent and indehiscent pods. Moreover, genome-wide comparative analysis revealed that orthogroups represented <1% of all identified differentially expressed genes could be traced among the four genera of legumes, while recruiting paralogous members may constitute the genetic robustness of legume pod dehiscence. This study compared the genetic mechanism among several legumes in pod dehiscence formation and revealed a compensating role of paralogous redundancy of involved gene families in seed dispersal, which can guide crop breeding.

• Klíčová slova
• domestication, gene expression, genetic basis, legumes, lignin, pod dehiscence,
• MeSH
• buněčná stěna metabolismus   genetika   MeSH
• Fabaceae * genetika   MeSH
• lignin metabolismus   MeSH
• multigenová rodina MeSH
• regulace genové exprese u rostlin MeSH
• rostlinné proteiny genetika   MeSH
• semena rostlinná genetika   MeSH
• transkriptom MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lignin MeSH
• rostlinné proteiny MeSH

Corneal dystrophies are phenotypically and genetically heterogeneous, often resulting in visual impairment caused by corneal opacification. We investigated the genetic cause of an autosomal dominant corneal stromal dystrophy in a pedigree with eight affected individuals in three generations. Affected individuals had diffuse central stromal opacity, with reduced visual acuity in older family members. Histopathology of affected cornea tissue removed during surgery revealed mild stromal textural alterations with alcianophilic deposits. Whole genome sequence data were generated for four affected individuals. No rare variants (MAF < 0.001) were identified in established corneal dystrophy genes. However, a novel heterozygous missense variant in exon 4 of SPARCL1, NM_004684: c.334G > A; p.(Glu112Lys), which is predicted to be damaging, segregated with disease. SPARC-like protein 1 (SPARCL1) is a secreted matricellular protein involved in cell migration, cell adhesion, tissue repair, and remodelling. Interestingly, SPARCL1 has been shown to regulate decorin. Heterozygous variants in DCN, encoding decorin, cause autosomal dominant congenital stromal corneal dystrophy, suggesting a common pathogenic pathway. Therefore, we performed immunohistochemistry to compare SPARCL1 and decorin localisation in corneal tissue from an affected family member and an unaffected control. Strikingly, the level of decorin was significantly decreased in the corneal stroma of the affected tissue, and SPARCL1 appeared to be retained in the epithelium. In summary, we describe a novel autosomal dominant corneal stromal dystrophy associated with a missense variant in SPARCL1, extending the phenotypic and genetic heterogeneity of inherited corneal disease.

• MeSH
• dědičné dystrofie rohovky * genetika   patologie   MeSH
• dekorin genetika   metabolismus   MeSH
• dospělí MeSH
• extracelulární matrix - proteiny * genetika   MeSH
• heterozygot MeSH
• lidé středního věku MeSH
• lidé MeSH
• missense mutace * MeSH
• proteiny vázající vápník * genetika   MeSH
• rodokmen * MeSH
• senioři MeSH
• stroma rohovky patologie   metabolismus   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dekorin MeSH
• extracelulární matrix - proteiny * MeSH
• proteiny vázající vápník * MeSH
• SPARCL1 protein, human MeSH Prohlížeč

Purple photosynthetic bacteria (PPB) are versatile microorganisms capable of producing various value-added chemicals, e.g., biopolymers and biofuels. They employ diverse metabolic pathways, allowing them to adapt to various growth conditions and even extreme environments. Thus, they are ideal organisms for the Next Generation Industrial Biotechnology concept of reducing the risk of contamination by using naturally robust extremophiles. Unfortunately, the potential of PPB for use in biotechnology is hampered by missing knowledge on regulations of their metabolism. Although Rhodospirillum rubrum represents a model purple bacterium studied for polyhydroxyalkanoate and hydrogen production, light/chemical energy conversion, and nitrogen fixation, little is known regarding the regulation of its metabolism at the transcriptomic level. Using RNA sequencing, we compared gene expression during the cultivation utilizing fructose and acetate as substrates in case of the wild-type strain R. rubrum DSM 467T and its knock-out mutant strain that is missing two polyhydroxyalkanoate synthases PhaC1 and PhaC2. During this first genome-wide expression study of R. rubrum, we were able to characterize cultivation-driven transcriptomic changes and to annotate non-coding elements as small RNAs.

• Klíčová slova
• Acetate, Depolymerase knock-out, Fructose, Gene ontology, Genome, Metabolism, Polyhydroxyalkanoates, RNA-Seq, Rhodospirillum rubrum, Transcriptome,
• Publikační typ
• časopisecké články MeSH