Biology subjects

Tani, N.

Publications and source records attributed to Tani, N..

At least 19 recordsLinked to original sources

bioRxiv2026

Firrm functions as a multiprotein interaction platform that coordinates Mcm8-9-Hrob recruitment and Fignl1-mediated Rad51 unloading

Rad51 forms nucleoprotein filaments to catalyze homology search and strand exchange. The transition to recombination-associated DNA synthesis is accompanied by Rad51 unloading and recombination helicase recruitment. However, how these reactions are coordinated remains unclear. Using Xenopus egg extracts, we identify a mechanistic coupling between Rad51 unloading and recombination helicase recruitment. Proteomic analysis revealed that Rad51 filaments assembled on double-stranded DNA recruit a limited set of recombination regulators, including C1orf112/Firrm, Fignl1, Mcm8, Mcm9, and Hrob. Firrm forms a stoichiometric complex with Fignl1 and directly binds short acidic motifs in the intrinsically disordered regions of both Mcm9 and Hrob. The Firrm-Mcm9 interaction promotes recruitment of Mcm8-9 and Hrob to Rad51 filaments. Purified Mcm8-9 stimulates the ATPase activity of Fignl1 through Firrm in a DNA-dependent manner. Rad51 unloading from double-stranded DNA depends primarily on Fignl1 ATPase activity and is stimulated by Firrm-Mcm9 interaction. In human cells, FIRRM-FIGNL1 and MCM8-9-HROB act in the same genetic pathway to confer resistance to DNA interstrand crosslinks. These results support a model in which Rad51 filaments and Firrm-Fignl1 promote recruitment of Mcm8-9-Hrob, which, in turn, stimulates Fignl1 ATPase activity, thereby coupling recombination helicase recruitment with Rad51 unloading.

molecular biology↗

bioRxiv2026

Chromosome-level genome assembly of Falcataria falcata provides insights into ancient polyploidy and duplicate gene evolution in Fabaceae

Whole-genome duplication (WGD) has played a fundamental role in shaping plant genome evolution, yet the timing and independence of WGD events in major Fabaceae subfamilies, including Caesalpinioideae and Papilionoideae, remain debated. Here, we present a chromosome-level genome assembly of the tropical mimosoid tree Falcataria falcata within Caesalpinioideae and investigate the evolutionary consequences of ancient polyploidy. The assembled genome spans 614.9 Mb with 13 chromosome-level scaffolds and 99.6% completeness based on BUSCO assessment, providing a high-quality resource for comparative genomics. Synteny analyses revealed conserved macrosyntenic structures shared across Caesalpinioideae, consistent with an ancestral WGD event predating lineage diversification. In contrast, analyses of synonymous substitution rates (Ks) and phylogenetic relationships of conserved duplicate genes support independent WGD events in Caesalpinioideae and Papilionoideae. We further show that lineage-specific variation in synonymous substitution rates is negatively associated with the retention of WGD-derived duplicates following the ancestral WGD in Caesalpinioideae, suggesting that evolutionary rate heterogeneity plays a key role in post-WGD genome evolution. In addition, recent gene duplicates that arose independently in each lineage after WGD exhibit elevated Ka/Ks ratios and are predominantly associated with defense responses to diverse biotic stresses, suggesting more rapid sequence evolution and functional divergence compared with WGD-derived duplicates. Together, our results reveal how ancient WGD, lineage-specific evolutionary rates, and subsequent gene duplication have jointly structured genome evolution in Fabaceae. The genome of F. falcata provides a valuable resource for understanding the long-term evolutionary consequences of polyploidy and the diversification of ecological adaptations in legumes.

genomics↗

bioRxiv2026

Replication protein A prevents unregulated priming and Rad51 loading on single-stranded DNA in nuclear extracts of Xenopus eggs

In eukaryotes, single-stranded DNA (ssDNA) generated during DNA replication, recombination, and repair is rapidly bound and protected by the major single-stranded DNA-binding protein replication protein A (RPA). RPA not only stabilizes ssDNA but also acts as a central platform that coordinates diverse DNA transactions. Exhaustion of RPA due to unregulated ssDNA production leads to replication fork breakage and replication catastrophe, underscoring its critical role in genome stability. However, the direct consequences of RPA limitation remain incompletely understood. Using Xenopus egg extracts, we show that excess ssDNA induces spontaneous priming, a reaction that is otherwise prevented in a physiological nuclear environment. We provide evidence that priming suppression is mediated by stoichiometric binding of RPA to ssDNA. Analysis of the ssDNA-binding proteome reveals that RPA promotes the association of ATR checkpoint factors, Pol-primase, and the RFWD3 ubiquitin ligase with ssDNA. In contrast, RPA depletion induces the recruitment of Rad51, Rad51 paralogs, and Fbh1, a DNA helicase that interacts with both RPA and Rad51 and promotes fork breakage under replication stress. Collectively, our findings suggest that RPA contributes to genome stability by protecting ssDNA from inappropriate DNA synthesis and unscheduled recruitment of recombination and fork-processing factors.

biochemistry↗

bioRxiv2026

Circadian Timekeeping in the Tropics: Rhythmic Transcriptome and Diurnal Regulatory Networks in Rubroshorea leprosula

Circadian rhythms allow plants to regulate internal processes to align with daily rhythms in the environment. Comparing circadian clocks across environments is essential because latitude-dependent variation in light and temperature imposes distinct selection pressures that shape the evolution and function of circadian timing systems. However, circadian clock studies have largely focused on temperate and subtropical species, leaving transcriptional circadian networks in tropical plants under relatively constant environments poorly understood. We report the first comprehensive circadian transcriptome of the ecologically important dipterocarp species Rubroshorea leprosula, a dominant species in tropical rainforests in Southeast Asia. One sapling was sampled every four hours for 48 hours under constant darkness and used for transcriptomic analyses. Only 283 of 20,748 expressed genes ([~]1.3%) exhibited significant circadian oscillations, with periods strongly concentrated between 23 and 25 h. Hierarchical clustering revealed four temporal clusters with alternate phases of expression and functional specialisation; morning clusters in processes related to light and chloroplast, midday clusters in hormone and signalling mechanisms, afternoon clusters in mitochondrial and peptide biosynthesis functions, and night clusters in protein quality control and autophagy. Comparative analysis identified clear orthologs for all major Arabidopsis circadian clock components (LHY, CCA1, PRRs, TOC1, ELF4, LUX, GI, ZTL, RVEs), with conserved synteny to Parashorea chinensis, a close relative of R. leprosula. Time-lagged cross-correlation (TLCC) network reconstruction identified a characteristic circadian topological similarity with Arabidopsis, including coupled morning and evening feedback loops and paralog expansion that maintained overall structure. Peak expression timing of these core clock genes in the tropical tree was largely consistent with that observed in Arabidopsis thaliana. In contrast to this conserved phase relationship, Rubroshorea orthologs exhibited reduced amplitudes and lower coefficients of variation in their circadian oscillations, suggesting diminished robustness of rhythmic gene expression. These findings demonstrate a conserved but regulated circadian mechanism in R. leprosula, in preparation for adaptation to tropical rainforests stable light and temperature regimes. This study lays the molecular foundation for circadian regulation in dipterocarps and offers a system for integrating rhythmic gene expression to ecological function and forest productivity in tropical communities.

plant biology↗

bioRxiv2026

Prenatal Maternal Inflammation Is Associated with Altered Offspring Mesolimbic White Matter Circuitry Observed in Late Midlife

BackgroundExposure to prenatal maternal inflammation (PNMI) has been linked to neurodevelopmental alterations in human offspring. Preclinical studies suggest that PNMI disrupts reward circuitry, particularly within mesolimbic circuits. However, the effects of PNMI on mesolimbic circuits (i.e, ventral tegmental area (VTA) projections to the hippocampus (VTA-H) and limbic striatum (VTA-LS)) in humans are not yet known. MethodsData for PNMI biomarkers [interleukin (IL)-6, IL-8, IL-1 receptor antagonist (IL-1ra), soluble TNF receptor-II (sTNF-RII)] from first trimester (T1) and second trimester (T2) maternal sera, and offspring MRI brain scans in late midlife (aged 57-63 years), were available for 89 mother-offspring dyads. Probabilistic tractography delineated bilateral VTA-H and VTA-LS tracts. Macrostructural tract measures were examined using hierarchical linear regressions. Microstructural integrity was assessed using neurite orientation dispersion and density imaging, and permutation-based cluster analyses. ResultsHigher T2 IL-1ra was associated with increased macrostructure (left VTA-H tract), whereas higher T2 sTNF-RII was associated with reduced macrostructure (right VTA-H and VTA-LS tracts) and higher T2 IL-8 (bilateral VTA-LS tracts). Microstructurally, higher T2 IL-6 was associated with increased neurite density (distal cluster, right VTA-H tract), while higher T1 IL-8 was associated with reduced neurite density (near the hippocampus in the left VTA-H tract, near the VTA in bilateral VTA-LS tracts). ConclusionsPNMI was associated with altered mesolimbic reward circuitry in offspring. This suggests that prenatal inflammation may contribute to affective and motivational disorders in offspring via alterations in mesolimbic circuitry.

neuroscience↗

bioRxiv2026

Ripples precede insight in the right human hippocampus

Insight is a sudden transition from uncertainty to awareness of a solution, often preceded by non-conscious processing. Despite the ubiquity of insights in human cognition, the neural mechanisms underlying this pre-conscious restructuring phase remain largely unknown. Recent theoretical frameworks suggest that the hippocampus, through its capacity for rapid associative retrieval and flexible recombination of stored representations, may facilitate the non-conscious exploration that precedes insight. Hippocampal ripples associated with memory replay and consolidation, represent a promising candidate mechanism for this process. We recorded intracranial local field potentials from depth electrodes in the hippocampus of ten patients with drug-resistant epilepsy while they performed non-verbal reasoning tasks. Participants indicated the moment of solution awareness via button press, enabling precise temporal alignment of neural activity to subjective insight. We observed a significant increase in ripple rate during a pre-response window. Critically, this effect was lateralized to the right hippocampus. These findings provide the first direct human electrophysiological evidence linking right-lateralized hippocampal ripples to the non-conscious phase of insight. We propose that right hippocampal ripples support rapid retrieval and flexible recombination of representations, potentially triggering cortical processes that culminate in conscious solution awareness.

neuroscience↗

bioRxiv2025

MAP7-driven cytoskeletal cross-talk establishes Sertoli cell polarity crucial for germ cell meiotic progression

How specialized apical membrane domains are assembled in vivo remains poorly understood. In the mouse testis, Sertoli cells build a luminal apical domain after birth that organizes the seminiferous epithelium and supports germ cell differentiation, distinct from fetal polarity established during cord formation. Here, we identify the microtubule-associated protein MAP7 as a key regulator of cytoskeletal organization during apical domain formation. MAP7 preferentially localizes to apical microtubules in Sertoli cells, showing limited overlap with stable microtubule markers. Native-tissue imaging indicates that MAP7-decorated microtubules, initially lacking obvious directionality, become increasingly aligned along the tubule axis as the apical domain matures. In Map7-deficient testes, microtubule abundance is maintained, but higher-order organization is disrupted and accompanied by persistent luminal F-actin accumulation. These defects compromise apical domain maturation and lumen formation during the first wave of spermatogenesis and are associated with altered tight-junction patterning. Proteomic analysis identifies the non-muscle myosin II heavy chains MYH9 and MYH10 among MAP7-associated proteins. MYH9 becomes enriched at luminal regions where microtubules and F-actin converge, but remains diffuse in Map7-deficient Sertoli cells despite ectopic luminal cytoskeletal assemblies, suggesting that MAP7 helps establish a cytoskeletal context that supports spatially restricted NMII enrichment. Single-cell RNA sequencing shows that Sertoli transcriptional differentiation largely proceeds without MAP7, whereas germ cells exhibit delayed meiotic progression with expansion of pachytene-stage subpopulations. Together, these findings establish MAP7-dependent microtubule remodeling as an organizing mechanism for postnatal apical domain maturation and suggest how epithelial cytoskeletal architecture shapes a niche that helps pace developmental progression of neighboring germ cells.

cell biology↗

bioRxiv2024

Periplasmic serine protease Prc is responsible for amyloid subunit CsgA degradation and proteostasis in Escherichia coli

Escherichia coli synthesizes curli amyloid fibers extracellularly during biofilm formation and host colonization. The proteostasis network regulates the major curli subunit, CsgA, to prevent intracellular amyloid aggregation, yet the degradation mechanism remains elusive. Here, through a comprehensive investigation employing genetically engineered E. coli, multi-copy-suppressor screening, and biochemical analyses, we identify periplasmic serine protease Prc as a key player in CsgA degradation. Prc directly degrades CsgA through internal cleavage, differing from canonical tail-specific proteases. Although the bacterial HtrA homologs DegP and DegQ exhibit limited CsgA degradation activity in vitro in the presence of the suicide activator YjfN, deletion of these proteases did not affect native CsgA degradation in vivo. Instead, Prc, in coordination with the periplasmic chaperone CsgC, prevents the periplasmic accumulation of CsgA amyloid-like aggregates. Additionally, disruptions in secretion efficiency and proteolytic systems reduce csg operon expression through activation of the Rcs and Cpx two-component systems. These findings reveal a dual-layered strategy employed by E. coli to prevent intracellular accumulation of extracellular amyloids at both protein degradation and transcriptional regulation levels. This study provides insights into the mechanisms ensuring cellular homeostasis during curli biogenesis.

microbiology↗

bioRxiv2024

Meioc-Piwil1 complexes regulate rRNA transcription for differentiation of spermatogonial stem cells

Ribosome biogenesis is vital for sustaining stem cell properties, yet its regulatory mechanisms are obscure. Herein, we show unique properties of zebrafish meioc mutants in which spermatogonial stem cells (SSCs) do not differentiate or upregulate rRNAs. Meioc colocalized with Piwil1 in perinuclear germ granules, but Meioc depletion resulted in Piwil1 accumulation in nucleoli. Nucleolar Piwil1 interacted with 45S pre-rRNA. piwil1+/-spermatogonia with reduced Piwil1 upregulated rRNAs, and piwil1+/-;meioc-/- spermatogonia recovered differentiation later than those in meioc-/-. Further, Piwil1 interacted with Setdb1 and HP1, and meioc-/- spermatogonia exhibited high levels of H3K9me3 and methylated CpG in the 45S-rDNA region. These results indicate that zebrafish SSCs maintain low levels of rRNA transcription with repressive marks similar to Drosophila piRNA targets of RNA polymerase II, and that Meioc has a unique function on preventing localization of Piwil1 in nucleoli to upregulate rRNA transcripts and to promote SSC differentiation.

developmental biology↗

bioRxiv2024

Image retrieval based on closed-loop visual-semantic neural decoding

Neural decoding via the latent space of deep neural network models can infer perceived and imagined images from neural activities, even when the image is novel for the subject and decoder. Brain-computer interfaces (BCIs) using the latent space enable a subject to retrieve intended image from a large dataset on the basis of their neural activities but have not yet been realized. Here, we used neural decoding in a closed-loop condition to retrieve images of the instructed categories from 2.3 million images on the basis of the latent vector inferred from electrocorticographic signals of visual cortices. Using a latent space of contrastive language-image pretraining (CLIP) model, two subjects retrieved images with significant accuracy exceeding 80% for two instructions. In contrast, the image retrieval failed using the latent space of another model, AlexNet. In another task to imagine an image while viewing a different image, the imagery made the inferred latent vector significantly closer to the vector of the imagined category in the CLIP latent space but significantly further away in the AlexNet latent space, although the same electrocorticographic signals from nine subjects were decoded. Humans can retrieve the intended information via a closed-loop BCI with an appropriate latent space.

neuroscience↗

bioRxiv2024

Parasitoid wasp venoms degrade Drosophila imaginal discs for successful parasitism

Parasitoid wasps, one of the most diverse and species-rich animal taxa on Earth, produce venoms that manipulate host development and physiology to exploit host resources. However, mechanisms of venom action remain poorly understood. Here, we show that infection of host Drosophila by the endoparasitoid wasp, Asobara japonica, triggers imaginal disc degradation (IDD) by inducing apoptosis, autophagy, and mitotic arrest, leading to impaired host metamorphosis. A multi-omics approach identified two venom proteins of A. japonica necessary for IDD. Knockdown experiments targeting the venom genes revealed that in concert with host immune suppression, IDD is essential for successful parasitism. Our study highlights a venom-mediated hijacking strategy of the parasitoid wasp that allows host larvae to grow, but ultimately kills the hosts.

developmental biology↗

bioRxiv2024

Accurate localization of cortical and subcortical sources of M/EEG signals by a convolutional neural network with a realistic head conductivity model: Validation with M/EEG simulation, evoked potentials, and invasive recordings

While electroencephalography (EEG) and magnetoencephalography (MEG) are well-established non-invasive methods in neuroscience and clinical medicine, they suffer from low spatial resolution. Particularly challenging is the accurate localization of subcortical sources of M/EEG, which remains a subject of debate. To address this issue, we propose a four-layered convolutional neural network (4LCNN) designed to precisely locate both cortical and subcortical source activity underlying M/EEG signals. The 4LCNN was trained using a vast dataset generated by forward M/EEG simulations based on a realistic head volume conductor model. The 4LCNN implicitly learns the characteristics of M/EEG and their sources from the training data without need for explicitly formulating and fine-tuning optimal priors, a common challenge in conventional M/EEG source imaging techniques. We evaluated the efficacy of the 4LCNN model on a validation dataset comprising forward M/EEG simulations and two types of real experimental data from humans: 1) somatosensory evoked potentials recorded by EEG, and 2) simultaneous recordings from invasive electrodes implanted in the brain and MEG signals. Our results demonstrate that the 4LCNN provides robust and superior estimation accuracy compared to conventional M/EEG source imaging methods, aligning well with established neuroscience knowledge. Notably, the accuracy of the subcortical regions was as accurate as that of the cortical regions. The 4LCNN method, as a data-driven approach, enables accurate source localization of M/EEG signals, including in subcortical regions, suggesting future contributions to various research endeavors such as contributions to the clinical diagnosis, understanding of the pathophysiology of various neuronal diseases and basic brain functions.

neuroscience↗

bioRxiv2023

Atypical heat shock transcription factor HSF5 is critical for male meiotic prophase under non-stress conditions

Meiotic prophase progression is differently regulated in males and females. In males, pachytene transition during meiotic prophase is accompanied by robust alteration in gene expression. However, how gene expression is regulated differently to ensure meiotic prophase completion in males remains elusive. Herein, we identified HSF5 as a male germ cell-specific heat shock transcription factor (HSF) for meiotic prophase progression. Genetic analyses and single-cell RNA-sequencing demonstrated that HSF5 is essential for progression beyond the pachytene stage under non-stress conditions rather than heat stress. Chromatin binding analysis in vivo and DNA-binding assays in vitro suggested that HSF5 binds to promoters in a subset of genes associated with chromatin organization. HSF5 recognizes a DNA motif different from typical heat shock elements recognized by other canonical HSFs. This study suggests that HSF5 is an atypical HSF that enforces the gene expression program for pachytene transition during meiotic prophase in males.

developmental biology↗

bioRxiv2023

Mettl1-dependent m7G tRNA modification is essential for maintaining spermatogenesis and fertility in Drosophila melanogaster

N7-methylguanosine (m7G) in the variable loop region of tRNA is catalyzed by METTL1/WDR4 heterodimer and stabilizes target tRNA. Here, we reveal essential functions of Mettl1 in Drosophila fertility. Knockout of Mettl1 (Mettl1-KO) lost the elongated spermatids and mature sperm, which was fully rescued by a Mettl1-transgene expression, but not a catalytic-dead Mettl1 transgene. This demonstrates that Mettl1-dependent m7G is required for spermatogenesis. Mettl1-KO resulted in a loss of m7G modification on a subset of tRNAs and a decreased level of tRNA expression. Strikingly, overexpression of the translational elongation factor, EF11, which can compete with the rapid tRNA decay (RTD) pathway in S. cerevisiae, significantly counteracted the sterility of Mettl1-KO males, supporting a critical role of m7G modification of tRNAs in spermatogenesis. Ribosome profiling showed that Mettl1-KO led to the ribosome stalling at codons decoded by tRNAs that were reduced in expression. Mettl1-KO also significantly reduced the translation efficiency of genes involved in elongated spermatid formation and sperm stability. These findings reveal a developmental role for m7G tRNA modifications and indicate that m7G modification-dependent tRNA stability differs among tissues.

molecular biology↗

bioRxiv2023

Hippocampal sharp-wave ripples correlate with naturally occurring self-generated thoughts in humans

Core features of human cognition, for example, the experience of mind wandering, highlight the importance of the capacity to focus on information separate from the here and now. However, the brain mechanisms that underpin these self-generated states remain unclear. An emerging hypothesis is that self-generated states depend on the process of memory replay, which, in animals, is linked to sharp-wave ripples (SWRs) originating in the hippocampus. SWRs are transient high-frequency oscillations that exhibit circadian fluctuations and, in the laboratory, are important for memory and planning. Local field potentials were recorded from the hippocampus of 11 patients with epilepsy for up to 15 days, and experience sampling was used to describe their association with ongoing thought patterns. SWRs were correlated with patterns of vivid, intrusive ongoing thoughts unrelated to the task being performed, establishing their contribution to the ongoing thoughts that humans experience in daily life.

neuroscience↗

bioRxiv2023

The molecular clock in long-lived tropical trees is independent of growth rate

The rates of appearance of new mutations play a central role in evolution. However, mutational processes in natural environments and their relationship with growth rates are largely unknown, particular in tropical ecosystems with high biodiversity. Here, we examined the somatic mutation landscapes of two tropical trees, Shorea laevis (slow-growing) and S. leprosula (fast-growing), in central Borneo, Indonesia. Using newly-constructed genomes, we identified a greater number of somatic mutations in tropical trees than in temperate trees. In both species, we observed a linear increase in the number of somatic mutations with physical distance between branches. However, we found that the rate of somatic mutation accumulation per meter of growth was 3.7-fold higher in S. laevis than in S. leprosula. This difference in the somatic mutation rate was scaled with the slower growth rate of S. laevis compared to S. leprosula, resulting in a constant somatic mutation rate per year between the two species. We also found that somatic mutations are neutral within an individual, but those mutations transmitted to the next generation are subject to purifying selection. These findings suggest that somatic mutations accumulate with absolute time and older trees have a greater contribution towards generating genetic variation. Significance StatementThe significance of our study lies in the discovery of an absolute time-dependent accumulation of somatic mutations in long-lived tropical trees, independent of growth rate. Through a comparative analysis of somatic mutation landscapes in slow- and fast-growing species, we observed a clock-like accumulation of somatic mutations in both species, regardless of their growth rates. Although the majority of somatic mutations were restricted to a single branch, we also identified mutations present in multiple branches, likely transmitted during growth. Our findings suggest that older trees make a greater contribution towards generating genetic variation.

evolutionary biology↗

bioRxiv2022

EPI-589, a redox-active neuroprotectant, potently protects cultured cells from oxidative stress and alleviates symptomatic and pathological progression of motor neuron disease in the wobbler mouse

Oxidative stress is believed to play a significant role in the pathophysiology of amyotrophic lateral sclerosis (ALS), the most common form of motor neuron disease. The present study aims to firstly investigate the antioxidant activities of EPI-589, a small-molecule quinone derivative, under cell-free or cell culture conditions, and explore the in vivo efficacy of EPI-589 in the wobbler mouse model of human motor neuron disease. The reduced form of EPI-589 showed hydroxyl radical scavenging activities, whereas the oxidized form i.e. EPI-589 did not. In cellular models utilizing ALS patient-derived fibroblasts carrying mutations in the fused in sarcoma (FUS) gene or superoxide dismutase 1 (SOD1) gene, EPI-589 potently protected cells from oxidative stress induced by buthionine sulfoximine and ferric citrate. Protective effect of EPI-589 was also observed in culture of mouse immortalized striatal STHdHQ7/Q7 cells with cystine deprivation. In wobbler mice, oral administration of dietary EPI-589 provided long-lasting amelioration of both of deterioration of the rotarod walking performance and progression of forelimb deformity in wobbler mice throughout the treatment. In separate studies, we found that EPI-589 significantly suppressed changes of pathophysiological markers such as plasma phosphorylated neurofilament heavy chain, urinary 8-hydroxy-2-deoxyguanosine, and cervical N-acetylaspartate in untreated wobbler mice. Thus, the present study firstly demonstrates that EPI-589 is a highly potent, redox-active neuroprotectant and robustly delays the symptomatic and pathophysiological progression of motor neuron disease in the wobbler mouse, and these findings strongly encourage further exploration of the therapeutic potential of EPI-589 for the treatment of ALS.

pharmacology and toxicology↗

bioRxiv2021

FBXO47 is essential for preventing the synaptonemal complex from premature disassembly in mouse male meiosis

Meiotic prophase is a prolonged G2 phase that ensures the completion of numerous meiosis-specific chromosome events. During meiotic prophase, homologous chromosomes undergo synapsis to facilitate meiotic recombination yielding crossovers. It remains largely elusive how homolog synapsis is temporally maintained and destabilized during meiotic prophase. Here we show that FBXO47 is the stabilizer of synaptonemal complex during male meiotic prophase. Disruption of FBXO47 shows severe impact on homologous chromosome synapsis and DSB repair processes, leading to male infertility. Notably, in the absence of FBXO47, although once homologous chromosomes are synapsed, the synaptonemal complex is precociously disassembled before progressing beyond pachytene. Remarkably, Fbxo47 KO spermatocytes remain in earlier stage of meiotic prophase and lack crossovers, despite apparently exhibiting diplotene-like chromosome morphology. We propose that FBXO47 functions independently of SCF E3 ligase, and plays a crucial role in preventing synaptonemal complex from premature disassembly during cell cycle progression of meiotic prophase.

cell biology↗