BACKGROUND: Juvenile hormone (JH) is synthesized by the corpora allata (CA) and controls development and reproduction in insects. We recently used CRISPR/Cas9 to establish a line lacking the enzyme that catalyzes the final step of JH biosynthesis in mosquitoes, a P450 epoxidase. The CA of the epox-/- mutants do not synthesize epoxidized JH III but methyl farneosate (MF), a weak agonist of the JH receptor. Female epox-/- mosquitoes have reduced JH signaling and show a substantial loss of reproductive fitness. To understand the molecular basis of this loss of fitness, we constructed ovarian mRNA libraries of Ae. aegypti of the Orlando strain wild-type (WT) and epoxidase null mutants (epox-/-) and investigated differential expression of reproductive genes. RESULTS: We performed triplicate RNA-seq analyses of female WT and epox-/- ovaries dissected at four critical stages of oogenesis: Ovaries from newly eclosed females (0h), sugar-fed females at 4 days post-eclosion (4d SF), females 16h (16h BF), and 48 h after a blood meal (48h BF). Silencing of epoxidase resulted in a drastic change in the expression of thousands of genes. CONCLUSIONS: Our results suggest that epoxidase deficiency leads to a reduction in JH signaling that has significant effects on Ae. aegypti ovarian transcriptome profiles. Ecdysteroid titers are dysregulated in the mutants, leading to a significant delay in the expression of vitelline membrane genes and other transcripts. We discovered changes in the expression of 230 long non-coding RNAs (lncRNAs) that may play an important role in the regulation of ovarian genes.

• Klíčová slova
• Aedes aegypti, Ecdysteroids, Juvenile hormone, Ovaries, Transcriptome, lncRNA,
• MeSH
• Aedes * genetika   fyziologie   MeSH
• juvenilní hormony * metabolismus   MeSH
• oogeneze * genetika   MeSH
• ovarium * metabolismus   MeSH
• signální transdukce * genetika   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• juvenilní hormony * MeSH

UNLABELLED: The development of functional B lymphocytes during chicken embryogenesis relies on a series of tightly regulated processes. Precursor B cells migrate from the spleen via the blood to the bursa of Fabricius, where they colonize the bursal follicles to undergo further maturation and differentiation. To better understand the molecular mechanisms underlying early B cell migration in the chicken embryo, transcriptome analysis of B cells isolated from the spleen, blood, and bursa at embryonic days (ED) 12, ED14, and ED16 was performed. These findings suggest that sphingosine-1-phosphate (S1P) and its receptors regulate B cell presence in the bloodstream, while CCR7 and CXCR4 guide B cells to the bursa. Additionally, integrins and cell adhesion molecules, such as PECAM1, appear to facilitate transendothelial migration into the bursal mesenchyme. This study highlights a coordinated interplay between chemokines, integrins and cell adhesion molecules involved in B cell recruitment and colonization of the bursa microenvironment. These findings enhance our understanding of early B cell migration and shed light on the mechanisms governing B cell trafficking during chicken embryonic development. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12864-025-11749-w.

• Klíčová slova
• Adaptive immunity, B cell development, B cell migration, Bursa of Fabricius, Cell adhesion molecules, Chicken embryonic development, Transcriptomics,
• Publikační typ
• časopisecké články MeSH

The organs of many female animals are remodeled by reproduction. Using the mouse intestine, a striking and tractable model of organ resizing, we find that reproductive remodeling is anticipatory and distinct from diet- or microbiota-induced resizing. Reproductive remodeling involves partially irreversible elongation of the small intestine and fully reversible growth of its epithelial villi, associated with an expansion of isthmus progenitors and accelerated enterocyte migration. We identify induction of the SGLT3a transporter in a subset of enterocytes as an early reproductive hallmark. Electrophysiological and genetic interrogations indicate that SGLT3a does not sustain digestive functions or enterocyte health; rather, it detects protons and sodium to extrinsically support the expansion of adjacent Fgfbp1-positive isthmus progenitors, promoting villus growth. Our findings reveal unanticipated specificity to physiological organ remodeling. We suggest that organ- and state-specific growth programs could be leveraged to improve pregnancy outcomes or prevent maladaptive consequences of such growth.

• Klíčová slova
• Fgfbp1, SGLT3a, adult organ remodeling, intestinal epithelium, isthmus progenitor, lactation, plasticity, pregnancy, reproduction, small intestine,
• MeSH
• enterocyty metabolismus   cytologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• pohyb buněk MeSH
• rozmnožování * fyziologie   MeSH
• střeva * růst a vývoj   MeSH
• střevní sliznice metabolismus   MeSH
• těhotenství MeSH
• tenké střevo * růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The canonical Wnt signaling pathway controls the continuous renewal of the intestinal epithelium and the specification of epithelial cell lineages. Tcf4, a nuclear mediator of Wnt signaling, is essential for the differentiation and maintenance of Paneth cells in the small intestine. Its deficiency is associated with reduced expression of key α-defensins, highlighting its role in host-microbe interactions. However, the exact function of Tcf4 in specifying the secretory lineage and its contribution to antimicrobial peptide production remain incompletely understood. Remarkably, α-defensin expression has also been detected in human colon adenomas, where aberrant Wnt signaling is a hallmark. This raises important questions: What is the role of these Paneth-like cells in tumor biology, and how does Tcf4 influence their identity and function? METHODS: We investigated cell specification in small intestinal crypts and colon tumors using conditional Tcf7l2 deletion, cell type-specific Cre recombinases, and reporter alleles in mice. Transcriptomic (single-cell and bulk RNA sequencing) and histological analyses were performed and complemented by microbiome profiling, antibiotic treatment, and intestinal organoids to functionally validate the main findings. RESULTS: The inactivation of Tcf4 depletes Paneth cells and antimicrobial peptides, disrupting the gut microbiota balance. In secretory progenitors, loss of Tcf4 shifts differentiation toward goblet cells. In the small intestine, alternative secretory progenitors produce Wnt ligands to support stem cells and epithelial renewal in the absence of Paneth cells. In colon tumors, Paneth-like cells form a tumor cell population, express Wnt ligands, and require Tcf4 for their identity. Loss of Tcf4 redirects their differentiation toward goblet cells. CONCLUSIONS: Tcf4 controls the balance between Paneth and goblet cells and is essential for antimicrobial peptide production in the small intestine. In colon adenomas, Paneth-like tumor cells drive antimicrobial gene expression and provide Wnt3 ligands, which may have implications for cancer therapy.

• Klíčová slova
• Antimicrobial peptides, Colorectal cancer, Intestinal cell lineage, Intestinal crypt, Paneth cells, Single-cell transcriptomics,
• MeSH
• alfa-defensiny metabolismus   MeSH
• buněčná diferenciace MeSH
• lidé MeSH
• myši MeSH
• nádory tračníku * patologie   genetika   mikrobiologie   metabolismus   MeSH
• organoidy metabolismus   MeSH
• Panethovy buňky metabolismus   MeSH
• pohárkové buňky metabolismus   MeSH
• signální dráha Wnt MeSH
• střevní mikroflóra * MeSH
• tenké střevo * metabolismus   patologie   mikrobiologie   MeSH
• transkripční faktor 4 * metabolismus   genetika   MeSH
• transkriptom * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-defensiny MeSH
• Tcf4 protein, mouse MeSH Prohlížeč
• transkripční faktor 4 * MeSH

Kings and queens of termites are endowed with an extraordinary longevity coupled with lifelong fecundity. We recently reported that termite kings and queens display a dramatically increased enzymatic activity and abundance of telomerase in their somatic organs when compared to short-lived workers and soldiers. We hypothesized that this telomerase activation may represent a noncanonical pro-longevity function, independent of its canonical role in telomere maintenance. Here, we explore this avenue and investigate whether the presumed noncanonical role of telomerase may be due to alternative splicing of the catalytic telomerase subunit TERT and whether the subcellular localization of TERT isoforms differs among organs and castes in the termite Prorhinotermes simplex. We empirically confirm the expression of four in silico predicted splice variants (psTERT1-A, psTERT1-B, psTERT2-A, psTERT2-B), defined by N-terminal splicing implicating differential localizations, and C-terminal splicing giving rise to full-length and truncated isoforms. We show that the transcript proportions of the psTERT are caste- and tissue-specific and that the extranuclear full-length isoform TERT1-A is relatively enriched in the soma of neotenic kings and queens compared to their gonads and to the soma of workers. We also show that extranuclear TERT protein quantities are significantly higher in the soma of kings and queens compared to workers, namely due to the cytosolic TERT. Independently, we confirm by microscopy the extranuclear TERT localization in somatic organs. We conclude that the presumed pleiotropic action of telomerase combining the canonical nuclear role in telomere maintenance with extranuclear functions is driven by complex TERT splicing.

• Klíčová slova
• Isoptera, TERT, alternative splicing, longevity, telomerase, termites,
• MeSH
• alternativní sestřih MeSH
• dlouhověkost * MeSH
• hmyzí proteiny * metabolismus   genetika   MeSH
• Isoptera * fyziologie   enzymologie   genetika   MeSH
• protein - isoformy metabolismus   genetika   MeSH
• telomerasa * metabolismus   genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hmyzí proteiny * MeSH
• protein - isoformy MeSH
• telomerasa * MeSH

Flagellar motility is crucial for the swim-and-stick lifestyle of Rhodobacterales and plays an important role for bacterial-algal interactions. This alphaproteobacterial order contains three distinct types of flagellar gene clusters (FGCs) for the formation of a functional flagellum. Our phylogenetically broad taxon sampling of more than 300 genomes revealed that the most common FGC, the fla1-type, was probably already present in the common ancestor of Rhodobacterales and was strictly vertically inherited, while the other two FGC types, fla2 and fla3, were spread via horizontal operon transfers. Swimming of the marine model organism Phaeobacter inhibens DSM 17395 (Roseobacteraceae) is mediated by the archetypal fla1-type flagellum. Screening of 13,000 transposon mutants of P. inhibens on soft agar plates revealed that 40 genes, including four genes encoding conserved but not yet characterized proteins (CP1-4) within the FGC, are essential for motility. Exoproteome analyses indicated that CP1-4 are required at different stages of flagellar assembly. Only eight genes outside the FGC were identified as essential for swimming motility, including all three genes of the CtrA phosphorelay. Using comparative transcriptomics of ΔcckA, ΔchpT and ΔctrA mutants of the distantly related model organisms P. inhibens and Dinoroseobacter shibae DFL 12, we identified genes for the flagellum and cyclic di-GMP turnover as core targets of the CtrA phosphorelay and a conserved connection with quorum sensing across members of the Rhodobacterales.

• Publikační typ
• časopisecké články MeSH
• preprinty MeSH

Malting is a critical step in barley (Hordeum vulgare) processing, transforming grain into a key raw material for brewing and food production. However, the process is often compromised by Fusarium spp., pathogens responsible for Fusarium Head Blight, which reduces grain quality and safety. Pulsed electric field (PEF) treatment, a promising non-thermal technology, has been studied for its potential to inactivate microbial pathogens and mitigate infection-related stress. In this study, we investigated transcriptional responses in barley infected with Fusarium spp. during malting, both with and without PEF treatment. RNA sequencing identified over 12,000 differentially expressed genes (DEGs) across four malting stages, with the third stage (24 h of germination) showing the highest transcriptional activity. DEGs were significantly enriched in pathways related to oxidative stress management and abscisic acid signaling, underscoring their importance in stress adaptation. Barley treated with PEF exhibited fewer DEGs in later malting stages compared to untreated samples, suggesting that PEF alleviates stress induced by both Fusarium infection and the malting process. Enrichment analysis further revealed that PEF treatment up-regulated stress-related pathways while down-regulating genes associated with photosynthesis and cell wall biogenesis. These findings provide novel insights into barley stress responses during malting and highlight the potential of PEF as a tool for enhancing malt quality under stress conditions.

• Klíčová slova
• Fusarium infection, Hordeum vulgare, gene expression, malting, pulsed electric field, stress response, transcriptomics,
• Publikační typ
• časopisecké články MeSH

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
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fumaráty MeSH
• kyslík MeSH
• rhodoquinone MeSH Prohlížeč
• sukcinátdehydrogenasa MeSH
• ubichinon * 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   fyziologie   růst a vývoj   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

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
• fyziologická adaptace * genetika   MeSH
• fyziologický stres genetika   MeSH
• molekulární evoluce MeSH
• symbióza * genetika   MeSH
• Tetrahymena * genetika   MeSH
• Publikační typ
• časopisecké články MeSH