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Lang, H.

Publications and source records attributed to Lang, H..

15 recordsLinked to original sources

In situ architecture of the basal body reveals regionalized assembly and central pair microtubules nucleation

The basal body (BB) is essential for axoneme assembly and ciliary function, and its defects are associated with ciliogenesis disorders and ciliopathies (1,2). However, the molecular basis of the BB's region-specific transitions along the proximal-distal axis, and the mechanism by which ciliary central pair (CP) microtubules are nucleated during ciliogenesis, have remained largely unknown. Here, we resolve the subnanometer architecture of native BBs in mammalian multiciliated cells using cryo-electron tomography and subtomogram averaging, and identify 11 ciliary-base microtubule-associated proteins (CMAPs), including 5 previously uncharacterized core components. These CMAPs localize specifically along ciliary base that facilitate the triplet-to-doublet microtubule transition. We further identify luminal gamma-tubulin ring complexes (gamma-TuRCs) anchored to the microtubule wall via the augmin complex, and propose that they may serve as candidate nucleation sites for CP microtubules biogenesis. Together, these findings define a molecular blueprint of the BB and provide a structural framework for understanding how regional architectural specialization and luminal nucleation collectively drive ciliary assembly and how their dysfunction causes ciliopathies.

cell biology↗

A Novel Central-Peripheral Interface: The Auditory Nerve Glial Transition Zone Exhibits Enhanced Age-Related Immune and Glial Cell Dysfunction

Age-related hearing loss (ARHL) is a rapidly growing public health concern, affecting two-thirds of adults over 65 years old, with no effective therapeutics available. As the aging population grows at an unprecedented rate, the burden of ARHL will only increase. The causes of ARHL are multifactorial, but an understudied major contributor is glial dysfunction. The auditory nerve (AN) conducts sound from the cochlea to the brainstem and holds a diverse population of immune cells and myelinating glia. As the AN fibers bundle together within the cochlea to project to the brainstem, they are first myelinated by Schwann cells in the peripheral AN, then myelinated by oligodendrocytes in the central AN. The region where myelination shifts from Schwann cells to oligodendrocytes is the glial transition zone (GTZ), located in the cochlear modiolus, creating a unique biological niche. While central-peripheral interfaces are recognized in other cranial nerves, the AN GTZ is understudied. This region integrates the peripheral and central microenvironments within the confined bony cochlea, positioning it as a niche for glial dysfunction in pathological conditions, such as aging. We hypothesize that the GTZ is a site of enhanced glial dysfunction contributing to age-related AN demyelination, an important contributor to ARHL. We evaluated this in an ARHL mouse model combining RNA-sequencing, quantitative immunohistochemistry, and 3D high-resolution imaging. We examined the AN GTZ from human temporal bone donors. RNA-sequencing of the AN revealed age-associated increases in abnormal myelination/glial function and inflammation. There was a significant age-dependent increase in Iba1+ macrophages/microglia, with accumulation at the AN GTZ, and an increase in cellular volume and surface area, suggesting greater age-related activation. Macrophages/microglia contained significantly more internalized myelin debris in the AN (peripheral, central, and GTZ) with aging. More importantly, we found structurally intact myelin within macrophages/microglia only at the GTZ, suggesting a unique microenvironment at the GTZ altering phagocytic activity in aging. Together, our data suggest that the GTZ, a previously unrecognized central-peripheral interface, is a critical site of immune-glial interactions and especially vulnerable to age-related demyelination and neuroinflammation. This study highlights the GTZ as a potential target for preserving AN myelination and mitigating ARHL.

neuroscience↗

The phosphodiesterase NbdA links c-di-GMP signaling to type IV pili function in Pseudomonas aeruginosa PAO1

The phosphodiesterase (PDE) NbdA (NO-induced biofilm dispersion locus A) consists of a membrane-integrated MHYT domain, a degenerated diguanylate cyclase (DGC) AGDEF domain and an EAL domain. The integral membrane domain MHYT is proposed to sense a so far unknown extracellular signal and transfers the information to the cytosolic enzyme domains to modulate cellular c-di-GMP level. Here, we show that full length NbdA from Pseudomonas aeruginosa PAO1 is an active PDE in vivo. In line with its PDE activity, overexpression leads to slightly reduced global c-di-GMP levels, and reduced twitching motility. Surprisingly, overexpression of truncated cytosolic NbdA variants exhibited increased c-diGMP levels, suggesting previously uncharacterized DGC activity despite lacking a canonical GGDEF motif. While full-length NbdA overexpression resulted in only slight c-di-GMP reduction, cytosolic variants induced a significant increase, indicating a potential for nonenzymatic effects like protein-protein interactions. Further investigation revealed a connection between NbdA and type IV pilus (T4P) function. Overexpression of NbdA conferred resistance to the T4P-dependent phage DMS3vir, suggesting interference with T4P assembly or function. Microscopic analysis demonstrated dynamic localization of NbdA, partially co-localizing with T4P components, supporting a role in T4P regulation. However, no clear link was re-established with flagellar motor switching or chemotaxis signaling. These findings position NbdA in the complex signaling network of c-diGMP and T4P-mediated surface behavior in P. aeruginosa. Future work will focus on elucidating the precise mechanisms of NbdAs PDE activity and its interplay with other DGC/PDE networks. ImportanceIn this work, we show the in vivo activity of the membrane-bound phosphodiesterase NbdA of Pseudomonas aeruginosa, its role in c-di-GMP homeostasis, cellular localization and implications in surface behavior. Using strains overexpressing NbdA and truncated protein variants, we detected a strong defect in growth on solid surfaces and an altered phage susceptibility. Co-localization experiments supported further the hypothesis of interaction with the type IV pilus apparatus. We propose for NbdA to be part of the protein network responsible for c-di-GMP level modulation at the cell pole and thereby regulating the function of type IV pilus apparatus.

microbiology↗

Reversible One-way Lipid Transfer at ER-Autophagosome Membrane Contact Sites via Bridge-like Lipid Transfer Protein Atg2

Bridge-like lipid transfer proteins (LTPs) contain a repeating {beta}-groove domain and long hydrophobic grooves that act as bridges at membrane contact sites (MCSs) to efficiently transfer lipids. Atg2 is one such bridge-like LTP essential for autophagosome formation, during which a newly synthesized isolation membrane (IM) emerges and expands through lipid supply. However, studies on Atg2-mediated lipid transfer are limited to in vitro studies due to the lack of a suitable probe for monitoring phospholipid dynamics in vivo. Here, we characterized the lipophilic dye octadecyl rhodamine B (R18), which internalizes and labels the endoplasmic reticulum (ER) in a manner that requires flippases and oxysterol-binding protein-related proteins. Using R18, we demonstrated phospholipid transfer from the ER to the IM during autophagy in vivo. Upon autophagy termination, we observed reversible phospholipid flow from the IM to the ER in response to environmental changes. Our findings highlight the critical role of bridge-like LTPs in MCS-mediated phospholipid homeostasis.

cell biology↗

TFE3 fusion proteins drive oxidative metabolism, ferroptosis resistance and general RNA synthesis in translocation renal cell carcinoma

The oncogenic mechanisms by which TFE3 fusion proteins drive translocation renal cell carcinoma (tRCC) are poorly characterised. Here, we integrated loss and gain of function experiments with multi-omics analyses in tRCC cell lines and patient tumors. High nuclear accumulation of NONO-TFE3 or PRCC-TFE3 fusion proteins promotes their broad binding across the genome at H3K27ac-marked active chromatin, engaging a core set of M/E-box-containing regulatory elements to activate specific gene expression programs as well as promiscuous binding to active promoters to stimulate mRNA synthesis. Within the core program, TFE3 fusions directly regulate genes involved in ferroptosis resistance and oxidative phosphorylation metabolism (OxPhos) increasing functional OxPhos levels. Consequently, human tRCC tumors display high OxPhos scores that persist during their epithelial to mesenchymal transition (EMT). We further show that tRCC tumour aggressiveness is related to their EMT and their associated enrichment in myofibroblast cancer-associated fibroblasts (myCAFs) that are both hallmarks of poor prognostic outcomes. We define tRCC as a novel metabolic subtype of renal cancer and provide unique insights into how broad genomic binding of TFE3 fusion proteins regulates OxPhos and ferroptosis resistance and more generally stimulates RNA synthesis. SynopsisDefining the gene expression programs regulated by TFE3 fusion proteins in translocation renal cell carcinoma. TFE3 fusion proteins promote expression of oxidative metabolism genes and oxidative metabolism in tRCC. TFE3 fusion proteins regulate glutathione metabolism and ferroptosis resistance in tRCC. TFE3 fusion proteins bind broadly at active promoters and stimulate RNA synthesis in tRCC. Epithelial-to-mesenchymal transition in tRCC is accompanied by enrichment in myofibroblastic cancer-associated-fibroblasts and poor patient outcome. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=187 SRC="FIGDIR/small/620047v2_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@b9dcb6org.highwire.dtl.DTLVardef@495f42org.highwire.dtl.DTLVardef@10d1770org.highwire.dtl.DTLVardef@7df40c_HPS_FORMAT_FIGEXP M_FIG C_FIG The paper explained. Problem.Translocation renal cell carcinoma (tRCC) is a rare subtype of kidney cancer characterised by genetic translocation events frequently involving transcription factor TFE3 or more rarely TFEB. While the resulting fusion proteins are considered as the oncogenic drivers, their mechanism of action remains poorly understood. Results.By integrative multi-omics analyses in tRCC cell lines and patient tumors together with loss and gain of function experiments, we found broad binding of TFE3-fusion proteins at active promoters and identified a core set of target genes involved in multiple pathways, including oxidative metabolism (OxPhos) and ferroptosis. Consequently, tRCC cell lines displayed higher functional OxPhos levels and patient tumours displayed elevated OxPhos scores and ferroptosis resistance gene expression. Analyses of tRCC patient transcriptome data further revealed that mesenchymal tRCC tumours are enriched in myofibroblastic cancer associated fibroblasts that are hallmarks of poor prognostic outcome. ImpactThis study advances understanding of the molecular mechanisms underlying oncogenic transformation by TFE3 fusion proteins by defining a core program of gene expression and key features of tumour cells and their microenvironment that negatively impact patient outcome. Our integrative multi-omics and functional analyses reveal how extensive genomic binding of TFE3 fusion proteins drives high levels of oxidative metabolism, ferroptosis resistance and general RNA synthesis.

cancer biology↗

Dihydromyricetin promotes GLP-1 secretion to improve insulin resistance via "gut microbiota-CDCA"

Dihydromyricetin (DHM) is a polyphenolic phytochemical found mainly in plants such as Ampelopsis grossedentata, which has beneficial effects on insulin resistance. However, the specific mechanism has not been clarified. In this study, C57BL/6 mice were exposed to a high-fat diet (HFD) for eight weeks. DHM could improve insulin resistance via enhancing the incretin effect. DHM increased serum GLP-1 by improving intestinal GLP-1 secretion and inhibiting GLP-1 decomposition, associated with the alteration of intestinal intraepithelial lymphocytes (IELs) proportions and decreased expression of CD26 in IELs and TCR{beta}+ CD8{beta}+ IELs in HFD-induced mice. Meanwhile, DHM could ameliorate GLP-1 level and insulin resistance by modulation of gut microbiota and the metabolites, particularly the regulation of intestinal bile acid CDCA content, followed by the inhibition of FXR expression in intestinal L cells as well as increased Gcg mRNA expression and the secretion of GLP-1. These findings clarify the role of the "gut microbiota-CDCA" pathway in the improvement of intestinal GLP-1 levels in HFD-induced mice by DHM administration, providing a new pharmacological target for the prevention of insulin resistance.

pharmacology and toxicology↗

Engineered symbiotic bacteria interfering Nosema redox system inhibit microsporidia parasitism in honeybees

Nosema ceranae is an emergent microsporidia parasite of the European honey bee (Apis mellifera), which causes serious nosemosis implicated in honeybee colony losses worldwide. N. ceranae is an obligate intracellular eukaryotic parasite that mainly invades the midgut of honeybees. Recent studies find that bee gut microbiota is potentially involved in protecting against parasitism. Here, using laboratory-generated bees mono-associated with gut members, we find that Snodgrassella alvi inhibited microsporidia proliferation, potentially via the stimulation of host oxidant-mediated immune response. Accordingly, N. ceranae employs the thioredoxin and glutathione systems to defend against oxidative stress and maintain a balanced redox equilibrium, which is essential for the infection process. We knocked down the gene expression using nanoparticle-mediated RNA interference, which targets the {gamma}-glutamyl-cysteine synthetase and thioredoxin reductase genes of microsporidia. It significantly reduces the spore load, confirming the importance of the antioxidant mechanism for the intracellular invasion of the N. ceranae parasite. Finally, we genetically modified the symbiotic S. alvi to deliver dsRNA corresponding to the genes involved in the redox system of the microsporidia. The engineered S. alvi induces RNA interference and represses parasite gene expression, thereby inhibits the parasitism by up to 99.8%. Specifically, N. ceranae was most suppressed by the recombinant strain corresponding to the glutathione synthetase or by a mixture of bacteria expressing variable dsRNA. Our findings extend our previous understanding of the protection of gut symbionts against N. ceranae and provide a symbiont-mediated RNAi system for inhibiting microsporidia infection in honeybees.

microbiology↗

Peripheral Auditory Nerve Impairment in a Mouse Model of Syndromic Autism

Dysfunction of the peripheral auditory nerve (AN) contributes to dynamic changes throughout the central auditory system, resulting in abnormal auditory processing, including hypersensitivity. Altered sound sensitivity is frequently observed in autism spectrum disorder (ASD), suggesting that AN deficits and changes in auditory information processing may contribute to ASD-associated symptoms, including social communication deficits and hyperacusis. The MEF2C transcription factor is associated with risk for several neurodevelopmental disorders, and mutations or deletions of MEF2C produce a haploinsufficiency syndrome characterized by ASD, language and cognitive deficits. A mouse model of this syndromic ASD (i.e., Mef2c+/- or Mef2c-Het) recapitulates many of the MEF2C Haploinsufficiency syndrome-linked behaviors including communication deficits. We show here that Mef2c-Het mice exhibit functional impairment of the peripheral AN and a modest reduction in hearing sensitivity. We find that MEF2C is expressed during development in multiple AN and cochlear cell types, and in Mef2c-Het mice, we observe multiple cellular and molecular alterations associated with the AN, including abnormal myelination, neuronal degeneration, neuronal mitochondria dysfunction, and increased macrophage activation and cochlear inflammation. These results reveal the importance of MEF2C function in inner ear development and function and the engagement of immune cells and other non-neuronal cells, which suggests that microglia/macrophages and other non-neuronal cells might contribute, directly or indirectly, to AN dysfunction and ASD-related phenotypes. Finally, our study establishes a comprehensive approach for characterizing AN function at the physiological, cellular, and molecular levels in mice, which can be applied to animal models with a wide range of human auditory processing impairments. Significance StatementThis is the first report of peripheral auditory nerve (AN) impairment in a mouse model of human MEF2C haploinsufficiency syndrome that has well-characterized ASD related behaviors including communication deficits, hyperactivity, repetitive behavior, and social deficits. We identify multiple underlying cellular, sub-cellular, and molecular abnormalities that may contribute to peripheral AN impairment. Our findings also highlight the important roles of immune cells (e.g., cochlear macrophages) and other non-neuronal elements (e.g., glial cells and cells in the stria vascularis) in auditory impairment in ASD. The methodological significance of the study is the establishment of a comprehensive approach for evaluating peripheral AN function and impact of peripheral AN deficits with minimal hearing loss.

neuroscience↗

Integrated molecular and pharmacological characterization of patient-derived xenografts from bladder and ureteral cancers identifies new potential therapies.

BackgroundMuscle-invasive bladder cancer (MIBC) and upper urinary tract urothelial carcinoma (UTUC) are molecularly heterogeneous. Despite chemotherapies, immunotherapies or anti-FGFR treatments, these tumors are still of poor outcome. Our objective was to develop a bank of patient-derived xenografts (PDXs) recapitulating molecular heterogeneity of MIBC and UTUC, to facilitate preclinical identification of therapies. MethodsFresh tumors were obtained from patients and subcutaneously engrafted into immune-compromised mice. Patient tumors and matched PDXs were compared regarding histopathology, transcriptomic (microarrays) and genomic profiles (targeted-NGS). Several PDXs were treated with chemotherapy (cisplatin/gemcitabine) or targeted therapies (FGFR and EGFR inhibitors). Results31 PDXs were established from 1 non-MIBC, 25 MIBC, 5 upper urinary tract tumors, including 28 urothelial (UCC) and 3 squamous-cell carcinomas (SCC). Integrated genomic and transcriptomic profiling identified PDXs of 3 different consensus molecular subtypes (Basal/Squamous, Luminal papillary and Luminal unstable), and included FGFR3-mutated PDXs. High histological and genomic concordance was found between matched patient tumor/PDX. Discordance in molecular subtypes, such as a basal/squamous patient tumor giving rise to a luminal papillary PDX, was observed (n=5) at molecular and histological levels. Ten models were treated with cisplatin-based chemotherapy and we did not observe association between subtypes and response. Of the 3 basal/squamous models treated with anti-EGFR therapy, two models were sensitive and one model, of sarcomatoid variant, was resistant. Treatment of 3 FGFR3-mutant PDXs with combined FGFR/EGFR inhibitors was more efficient than anti-FGFR3 treatment alone. ConclusionsWe developed preclinical PDX models that recapitulate the molecular heterogeneity of MIBCs and UTUC, including actionable mutations, which will represent an essential tool in therapy development. Pharmacological characterization of the PDXs suggested that upper urinary tract and MIBCs, UCC but also SCC, with similar molecular characteristics could benefit from the same treatments including anti-FGFR for FGFR3-mutated tumors and anti-EGFR for basal ones and showed a benefit for combined FGFR/EGFR inhibition in FGFR3-mutant PDXs, compared to FGFR inhibition alone.

cancer biology↗

The CIpP activator, TR-57, is highly effective as a single agent and in combination with venetoclax against CLL cells in vitro.

Despite advances in treatment, a significant proportion of patients with chronic lymphocytic leukaemia (CLL) will relapse with drug-resistant disease. Recent studies demonstrate that the imipridones ONC-201 and ONC-212 and the more potent TR-compounds are effective against a range of different cancers, including acute myeloid leukaemia and tumours of the brain, breast, and prostate. These drugs induce cell death through inhibition of mitochondrial function and activation of the mitochondrial protease, caseinolytic protease (CIpP), and the unfolded protein response (UPR). Here we demonstrate that a drug in this class, TR-57, has efficacy as a single agent and is synergistic with venetoclax against CLL cells cultured under in vitro conditions that mimic the tumour microenvironment. The inhibitory effects of TR-57 on cell survival, proliferation and migration were irrespective of poor-risk features, including aberrations of TP53. Changes in protein expression suggest the mechanisms of action of TR-57 and its synergy with venetoclax involve activation of the UPR, inhibition of the AKT and ERK1/2 pathways and a pro-apoptotic shift in expression of proteins of the BCL-2 family. The study suggests TR-57, as a single agent and in combination with venetoclax, may represent an effective treatment option for CLL, including for patients with poor-risk disease.

cancer biology↗

Age-Related Central Gain with Degraded Neural Synchrony in the Auditory Brainstem of Mice and Humans

Aging is associated with auditory nerve (AN) functional deficits and decreased inhibition in the central auditory system, amplifying central responses in a process known as central gain. Although central gain enhances response amplitudes, central gain may not restore disrupted response timing. In this translational study, we measured responses from the AN and auditory midbrain in younger and older mice and humans. We hypothesized that older mice and humans exhibit central gain without an improvement in inter-trial synchrony in the midbrain. Our data demonstrated greater age-related deficits in AN response amplitudes than auditory midbrain response amplitudes, as shown by significant interactions between neural generator and age group, indicating central gain in auditory midbrain. However, synchrony decreases with age in both the AN and midbrain responses. These results reveal age-related central gain without concomitant improvements in synchrony, consistent with those predictions based on decreases in inhibition. Persistent decreases in synchrony may contribute to auditory processing deficits in older mice and humans.

neuroscience↗

Characterization of TR-107, a Novel Chemical Activator of the Human Mitochondrial Protease ClpP

We recently described the identification of a new class of small molecule activators of the mitochondrial protease ClpP. These compounds synthesized by Madera Therapeutics showed increased potency of cancer growth inhibition over the related compound ONC201. In this study, we describe chemical optimization and characterization of the next generation of highly potent and selective small molecule ClpP activators (TR compounds) and demonstrate their efficacy against breast cancer models in vitro and in vivo. One of these compounds (TR-107) with excellent potency, specificity and drug-like properties was selected for further evaluation. Examination of TR-107 effects in triple-negative breast cancer (TNBC) cell models showed growth inhibition in the low nanomolar range, equipotent to paclitaxel, in a ClpP-dependent manner. TR-107 reduced specific mitochondrial proteins including OXPHOS and TCA cycle components, in a time, dose and ClpP-dependent manner. Seahorse XF analysis and glucose deprivation experiments confirmed inactivation of OXPHOS and demonstrated an increased dependence on glycolysis following TR-107 exposure. The pharmacokinetic properties of TR-107 were compared to other known ClpP activators including ONC201 and ONC212. TR-107 displayed excellent exposure and serum t1/2 after oral administration. The antitumor response to TR-107 was investigated using human TNBC MDA-MB-231 cell line-induced xenograft tumors. Oral administration of TR-107 resulted in reduction in tumor volume and extension of survival in the treated compared with vehicle control mice. In summary, we describe the identification of highly potent new ClpP agonists with improved efficacy against TNBC, through targeted inactivation of OXPHOS and disruption of mitochondrial metabolism.

pharmacology and toxicology↗

Integrative genomics uncover mechanisms of renal medullary carcinoma transformation, microenvironment landscape and therapeutic vulnerabilities.

Renal medullary carcinoma (RMC) is an aggressive desmoplastic tumour driven by bi-allelic loss of SMARCB1, however the cell-of-origin, the oncogenic mechanism and the features of its microenvironment remain poorly understood. Using single-cell and multi-region sequencing of human RMC, we defined transformation of thick ascending limb (TAL) cells into at least three RMC cell states along an epithelial-mesenchymal gradient through a transcriptional switch involving loss of renal transcription factor TFCP2L1 and gain of a NFE2L2-associated ferroptosis resistance program. SMARCB1 re-expression in cultured RMC cells reactivates TFCP2L1 that relocates SWI/SNF from the promoters of the MYC-driven oncogenic program to the enhancers of TAL identity genes followed by ferroptotic cell death. We further show that RMC is associated with abundant M2-type macrophages and cancer-associated fibroblasts (CAFs) and we identify key regulatory cross-talks that shape this immunosuppressive microenvironment. Together our data describe the molecular events of RMC transformation and identify novel therapeutically targetable vulnerabilities. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=64 SRC="FIGDIR/small/462391v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@152fa6eorg.highwire.dtl.DTLVardef@b76f50org.highwire.dtl.DTLVardef@ed1382org.highwire.dtl.DTLVardef@9be54f_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

Two distinct types of nodes of Ranvier support auditory nerve function in the mouse cochlea

Glial cells of the auditory nerve regulate formation of the nodes of Ranvier that are needed for regeneration of action potentials and proper hearing function. Here we identify and describe the distinct features of two novel types of Ranvier nodes--the axonal node and the ganglion node--in the mouse auditory nerve that change across the lifespan, including during myelination and postnatal development, and degenerate during aging. Cellular, molecular, and structure-function correlation evaluations revealed that nodal types are critical for different aspects of auditory nerve function. Specifically, the length of the axonal node is associated with neural processing speed and neural synchrony, whereas ganglion node development is associated with amplitude growth of the action potential. Moreover, our data indicate that dysregulation of glial cells and associated degeneration of the ganglion node structure are an important and new mechanism of auditory nerve dysfunction in age-related hearing loss.

neuroscience↗

Honeybee genetics shape the strain-level structure of gut microbiota in social transmission

Honeybee gut microbiota transmitted via social interactions are beneficial to the host health. Although the microbial community is relatively stable, individual variations and high strain-level diversity have been detected across honeybees. Although the bee gut microbiota structure is influenced by environmental factors, the heritability of the gut members and the contribution of the host genetics remains elusive. Considering bees within a colony are not readily genetically identical due to the polyandry of queen, we hypothesize that the microbiota structure can be shaped by host genetics. We used shotgun metagenomics to simultaneously profile the microbiota and host genotypes of individuals from hives of four different subspecies. Gut composition is more distant between genetically different bees at both phylotype- and "sequence-discrete population"-level. We then performed a successive passaging experiment within colonies of hybrid bees generated by artificial insemination, which revealed that the microbial composition dramatically shifts across batches of bees during the social transmission. Specifically, different strains from the phylotype of Snodgrassella alvi are preferentially selected by genetically varied hosts, and strains from different hosts show a remarkably biased distribution of single-nucleotide polymorphism in the Type IV pili loci. A genome-wide association analysis identified that the relative abundance of a cluster of Bifidobacterium strains is associated with the host glutamate receptor gene that is specifically expressed in the bee brain. Finally, mono-colonization of Bifidobacterium with a specific polysaccharide utilization locus impacts the expression and alternative splicing of the gluR-B gene, which is associated with an altered circulating metabolomic profile. Our results indicated that host genetics influence the bee gut composition, and suggest a gut-brain connection implicated in the gut bacterial strain preference. Honeybees have been used extensively as a model organism for social behaviors, genetics, and gut microbiome. Further identification of host genetic function as shaping force of microbial structure will advance our understanding of the host-microbe interactions.

microbiology↗