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Biology subjects

Han, C.

Publications and source records attributed to Han, C..

At least 73 records · Page 4Linked to original sources

A deep learning convolutional neural network distinguishes neuronal models of Parkinson's disease from matched controls

Parkinsons disease (PD) is a neurodegenerative disorder that results in the loss of dopaminergic neurons in the substantia nigra pars compacta. Despite advances in understanding PD, there is a critical need for novel therapeutics that can slow or halt its progression. Induced pluripotent stem cell (iPSC)-derived dopaminergic neurons have been used to model PD but measuring differences between PD and control cells in a robust, reproducible, and scalable manner remains a challenge. In this study, we developed a binary classifier convolutional neural network (CNN) to accurately classify microscopy images of PD models and matched control cells. We acquired images of iPSC-derived neural precursor cells (NPCs) and dopaminergic (DANs) and trained multiple CNN models comparing control cells to genetic and chemical models of PD. Our CNN accurately predicted whether control NPC cells were treated with the PD-inducing pesticide rotenone with 97.60% accuracy. We also compared control to a genetic model of PD (deletion of the Parkin gene) and found a predictive accuracy of 86.77% and 95.47% for NPC and DAN CNNs, respectively. Our cells were stained for nuclei, mitochondria, and plasma membrane, and we compared the contribution of each to the CNNs accuracy. Using all three features together produced the best accuracy, but nuclear staining alone produced a highly predictive CNN. Our study demonstrates the power of deep learning and computer vision for analyzing complex PD-related phenotypes in DANs and suggests that these tools hold promise for identifying new targets for therapy and improving our understanding of PD.

neuroscience↗

Study on the preparation of bovine milk exosomes and the stability of lyophilized powder

Bovune milk exosomes (MK-exo) have bioactive effects on the health of consumers and can also serve as excellent drug delivery vehicles. However, long-term preservation and transportation remain major challenges at present. In this report, high-quality MK-exo are prepared on a large scale. We then developed a lyophilization method belonging to MK-exo, and performed acceleration and long-term stability experiments on the lyophilized MK-exo to evaluate the effect of lyophilization. The results showed that the lyophilized MK-exo can be stored at room temperature for at least 3 months and 2-8{degrees}C for 15 months. These findings provide data support for further understanding of the properties and applications of MK-exo.

bioengineering↗

Light-induced trapping of endogenous proteins reveals spatiotemporal roles of microtubule and kinesin-1 in dendrite patterning of Drosophila sensory neurons

Animal development involves numerous molecular events, whose spatiotemporal properties largely determine the biological outcomes. Conventional methods for studying gene function lack the necessary spatiotemporal resolution for precise dissection of developmental mechanisms. Optogenetic approaches are powerful alternatives, but most existing tools rely on exogenous designer proteins that produce narrow outputs and cannot be applied to diverse or endogenous proteins. To address this limitation, we developed OptoTrap, a light-inducible protein trapping system that allows manipulation of endogenous proteins tagged with GFP or split GFP. This system turns on fast and is reversible in minutes or hours. We generated OptoTrap variants optimized for neurons and epithelial cells and demonstrate effective trapping of endogenous proteins of diverse sizes, subcellular locations, and functions. Furthermore, OptoTrap allowed us to instantly disrupt microtubules and inhibit the kinesin-1 motor in specific dendritic branches of Drosophila sensory neurons. Using OptoTrap, we obtained direct evidence that microtubules support the growth of highly dynamic dendrites. Similarly, targeted manipulation of Kinesin heavy chain revealed differential spatiotemporal requirements of kinesin-1 in the patterning of low- and high-order dendritic branches, suggesting that different cargos are needed for the growth of these branches. OptoTrap allows for precise manipulation of endogenous proteins in a spatiotemporal manner and thus holds great promise for studying developmental mechanisms in a wide range of cell types and developmental stages.

developmental biology↗

SaProt: Protein Language Modeling with Structure-aware Vocabulary

AO_SCPLOWBSTRACTC_SCPLOWLarge-scale protein language models (PLMs), such as the ESM family, have achieved remarkable performance in various downstream tasks related to protein structure and function by undergoing unsupervised training on residue sequences. They have become essential tools for researchers and practitioners in biology. However, a limitation of vanilla PLMs is their lack of explicit consideration for protein structure information, which suggests the potential for further improvement. Motivated by this, we introduce the concept of a "structure-aware vocabulary" that integrates residue tokens with structure tokens. The structure tokens are derived by encoding the 3D structure of proteins using Foldseek. We then propose SaProt, a large-scale general-purpose PLM trained on an extensive dataset comprising approximately 40 million protein sequences and structures. Through extensive evaluation, our SaProt model surpasses well-established and renowned baselines across 10 significant downstream tasks, demonstrating its exceptional capacity and broad applicability. We have made the code1, pre-trained model, and all relevant materials available at https://github.com/westlake-repl/SaProt.

bioinformatics↗

Generative Diffusion Models for Antibody Design, Docking, and Optimization

In recent years, optimizing antibody binding affinity for biomedical applications has become increasingly important. However, traditional wet-experiment-based approaches are time-consuming and inefficient. To address this issue, we propose a diffusion model-based antibody optimization pipeline to improve binding affinity. Our approach involves two key models: AbDesign for designing antibody sequences and structures, and AbDock, a paratope-epitope docking model, used for screening designed CDRs. On an independent test set, our AbDesign demonstrates the exceptional performance of an RMSD of 2.56[A] in structure design and an amino acid recovery of 36.47% in sequence design. In a paratope-epitope docking test set, our AbDock achieves a state-of-the-art performance of DockQ 0.44, irms 2.71[A], fnat 0.40, and Lrms 6.29[A]. The effectiveness of the optimization pipeline is further experimentally validated by optimizing a flaviviruse antibody 1G5.3, resulting in a broad-spectrum antibody that demonstrates improved binding to 6 out of the nine tested flaviviruses. This research offers a general-purpose methodology to enhance antibody functionality without training on data from specific antigens.

bioinformatics↗

Tissue-specific knockout in Drosophila neuromuscular system reveals ESCRT's role in formation of synapse-derived extracellular vesicles

Tissue-specific gene knockout by CRISPR/Cas9 is a powerful approach for characterizing gene functions in animal development. However, this approach has been successfully applied in only a small number of Drosophila tissues. The Drosophila motor nervous system is an excellent model system for studying the biology of neuromuscular junction (NMJ). To expand tissue-specific CRISPR to the Drosophila motor system, here we present a CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) toolkit for knocking out genes in motoneurons, muscles, and glial cells. We validated the efficacy of this toolkit by knocking out known genes in each tissue, demonstrated its orthogonal use with the Gal4/UAS binary expression system, and showed simultaneous knockout of multiple redundant genes. Using these tools, we discovered an essential role for SNARE pathways in NMJ maintenance. Furthermore, we demonstrate that the canonical ESCRT pathway suppresses NMJ bouton growth by downregulating the retrograde Gbb signaling. Lastly, we found that axon termini of motoneurons rely on ESCRT-mediated intra-axonal membrane trafficking to lease extracellular vesicles at the NMJ. SIGNIFICANCE STATEMENTIn this study, we developed a tissue-specific Cas9 toolkit that enables gene knockout specifically in motor neurons, glial cells, and muscle cells, the three cell types of the Drosophila peripheral motor system. Complementary to existing RNAi methods, this versatile tissue-specific knockout system offers unique advantages for dissecting gene functions at the neuromuscular junction (NMJ). Using these tools, we discovered that SNARE-mediated secretory pathways are required to maintain the integrity of the NMJ and that ESCRT components play critical yet differential roles in the biogenesis of extracellular vesicles, bouton growth, and membrane turnover at the NMJ. This CRISPR toolkit can be applied to study many biological questions in the neuromuscular system.

neuroscience↗

Genome-wide Perturbation Analysis Screening System for Exosomes-Related Genes Based on the CRISPR/Cas9 Platform

As reported previously, exosomes have significant impacts on the physiological and pathological state in vivo. Exosomes have been extensively studied as a drug delivery carrier and some exosomes drugs have been undergoing clinical research. The mechanisms of exosome production, transport, and secretion remain to be studied in depth. Thus, here, we developed a novel CRISPR-UMI-based gene screening system, with which we can reveal the exosomes biogenesis, transport, and uptake mechanisms on a genome-wide scale. This system consists of two parts: one is a gene knockout component; the other part is a unique molecular identifiers (UMI) labeling component that can label the exosomes produced by the knockout cells, in which each sgRNA corresponds to a specific UMI. In this way, by detecting the UMI loaded in the exosomes, we can trace the knockout gene. In this study, we first verified the function of each component using plasmids and lentiviruses respectively. Next, we simulated the infection of cells with lentiviral libraries using a single lentivirus to validate the functionality of the screening system. Finally, we constructed a CRISPR-UMI-based library targeting 15 genes (genes with clear effects on exosomes biogenesis) to further validate the reliability of the screening system. The development of this screening system is of indispensable importance for the in-depth study of the mechanisms of exosome production and secretion, as well as for the improvement of exosomes production and the advancement of exosomes industrialization.

bioengineering↗

Percutaneous Intramyocardial Septal Cryoablation: A Canine Model with 6 months Follow-up

BACKGROUNDEchocardiography-guided percutaneous intramyocardial septal radiofrequency ablation (PIMSRA, Liwen procedure) is a novel treatment option for hypertrophic obstructive cardiomyopathy (HOCM). The safety and feasibility of using this procedure for cryoablation are unknown. OBJECTIVETo establish a canine model for echocardiography-guided percutaneous intramyocardial septal cryoablation (PIMSCA). METHODSEight canines underwent PIMSCA and had electrocardiography, echocardiography, myocardial contrast echocardiography (MCE), (ECG), serological and pathological examinations during the preoperative, immediate postoperative, and in 6-month follow-up. RESULTSAll eight canines underwent successful cryoablation and continued to be in sinus rhythm during ablation and without malignant arrhythmias. MCE showed that ablation area had decreased myocardial perfusion after procedure. Troponin I levels were significantly elevated [0.010 (0.005, 0.297) ng/mL vs. 3.122 (1.152,7.990) ng/mL, p < 0.05)]. At follow-up 6-months after procedure, all animals were alive, with thinning of the interventricular septum (7.26 {+/-} 0.52 mm vs. 3.86 {+/-} 0.29 mm, p < 0.05). Echocardiography showed no significant decrease in left ventricular ejection fractions (LVEF) (54.32 {+/-} 2.93 %vs. 54.70 {+/-} 2.47 %, p > 0.05) or changes by pulse-wave Doppler E/A (1.17 {+/-} 0.43 vs. 1.07 {+/-} 0.43, p > 0.05), E/e(8.09 {+/-} 1.49 vs. 10.05 {+/-}2.68, p > 0.05). Pathological findings proved effective cryoablation in myocardial tissues. We observed pericardial effusions and premature ventricular complexes (PVCs) associated with the procedure. CONCLUSIONOur findings provide preliminary evidence of the safety and feasibility of PIMSACA in interventricular septum reduction, which provides a potentially new treatment option for HOCM.

zoology↗

Tumor-derived exosomal miR-222-3p induce cancer-associated fibroblasts activation to foster progression of renal cancer

The interaction between tumor-derived exosomes and stroma is crucial for tumor progression. However, the mechanisms by which tumor cells influence stromal changes are not yet fully understood. Our study revealed that high-metastatic renal cancer cells are more effective in converting normal fibroblasts into cancer-associated fibroblasts (CAFs) compared to low-metastatic renal cancer cells. Meanwhile, high-metastatic renal cancer cells secrete more exosomal miR-222-3p, which can directly target PANK3, activate NF-kB signaling pathway in fibroblasts and induce intracellular metabolic reprogramming to produce more lactic acid through Warburg effect. The activated CAFs further promote renal cancer progression by secreting lactic acid and inflammatory cytokines, including IL-6 and IL-8. Patients with renal cancer who have high levels of serum exocrine miR-222-3p are more likely to experience progression. These findings suggest that the intercellular communication between renal cancer cells and fibroblasts is facilitated by tumor exosomes. Targeting this communication may hold promise for the prevention and treatment of renal cancer.

cancer biology↗

A dual hit of α-synuclein internalization and immune challenge leads to formation and maintenance of Lewy body-like inclusions in human dopaminergic neurons

Lewy bodies (LBs), rich in -synuclein, are a hallmark of Parkinsons disease (PD). Understanding their biogenesis is likely to provide insight into the pathophysiology of PD, yet a cellular model for LB formation remains elusive. The realization that the immune challenge is a trigger for neurodegenerative diseases has been a breakthrough in the understanding of PD. Here, iPSC-derived human dopaminergic (DA) neurons from multiple healthy donors were found to form LB-like inclusions following treatment with - synuclein preformed fibrils, but only when coupled to an immune challenge (interferon-gamma or interleukin-1 beta) or when co-cultured with activated microglia. Human cortical neurons derived from the same iPSC lines did not form LB-like inclusions. Exposure to interferon-gamma impairs autophagy in a lysosomal-specific manner in vitro, similar to the disruption of proteostasis pathways that contribute to PD. We find that lysosomal membrane proteins LAMP1 and LAMP2 and transcription factors regulating lysosomal biogenesis and function are downregulated in DA but not cortical neurons. Finally, due to the excellent sample preservation afforded by cells compared to post-mortem PD brain tissue, we conclude that the LB-like inclusions in DA neurons are membrane-bound, suggesting they are not limited to the cytoplasmic compartment. In Brief O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=170 SRC="FIGDIR/small/542776v3_figabs.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@1f41855org.highwire.dtl.DTLVardef@69798dorg.highwire.dtl.DTLVardef@ab55bdorg.highwire.dtl.DTLVardef@8a16b8_HPS_FORMAT_FIGEXP M_FIG C_FIG Bayati et al. identify that iPSC-derived dopaminergic neurons undergoing a dual hit treatment of exogenous -synuclein fibrils and proinflammatory cytokines form Lewy body-like inclusions. The dual hit treatment also led to the downregulation of lysosomal proteins. Characterization of inclusions revealed that inclusions were membrane-bound and LC3B-positive, suggesting they are dysfunctional autophagosomes. HighlightsO_LI-synuclein preformed fibril administration coupled with Interferon-gamma exposure leads dopaminergic neurons to form Lewy body-like inclusions C_LIO_LIInclusions are filamentous, membranous, and filled with aberrant organelles C_LIO_LIImpaired autophagic flux and downregulation of TFEB, NRF2, LAMP1, and LAMP2 correlated with inclusion formation C_LIO_LIActivation of NRF2 through the treatment of neurons with the antioxidant perillaldehyde, prevents inclusion formation C_LI

neuroscience↗

Tumor microenvironment exploration and therapeutic target identification in bladder cancer based on Cuproptosis signature and chemotherapy-resistant model: results from bioinformatics and experimental validation

BackgroundThe discovery of cuproptosis provides a new way to make full use of the pathophysiological effects of copper for anticancer therapy and could help identify a therapeutic target in bladder cancer. MethodsIn this study, 411 BLCA tumor samples from the Cancer Genome Atlas (TCGA) cohort were obtained. Differentially expressed genes (DEGs) between chemotherapy-sensitive and chemotherapy-resistant mouse bladder cancers were also obtained. Sixteen genes were defined as cuproptosis-related genes (CRGs), and the cutoff score was calculated based on LASSO Cox regression. CCK-8 and Transwell assays were used to detect the migration and proliferation of 5637 and T24 cells, respectively. Liarozole dihydrochloride (L-D), a mild P450, inhibits the expression of CYP26B1. Multiple immunohistochemistry analyses were used to explore the association between the immune microenvironment and CRGs. ResultsA higher Cuproptosis score was significantly associated with worse overall survival in BLCA (p<0.0001, HR=2.32). Single-cell transcriptional data were used to assess the function of CYP26B1 and CYP26B1 may be negatively associated with DNA damage and repair. In vitro experiments indicated that overexpression of CYP26B1 enhanced the migration and proliferation of BLCA cells, while L-D inhibited the migration and proliferation of BLCA cells. A higher expression level of Dihydrolipoamide S-Succinyltransferase (DLST) serves could as a risk factor in patients treated with atezolizumab and higher expression of DLST suggest an immunosuppressive microenvironment. ConclusionsCYP26B1 may be a therapeutic target for bladder cancer, and the higher expression of DLST may suggest an immunosuppressive microenvironment in BLCA. Key MessagesCuproptosis may be associated with the chemotherapy-resistance of bladder cancer and our findings may provide new ideas for the treatment of bladder cancer.

genomics↗

Artificial intelligence redefines RNA virus discovery

Current metagenomic tools can fail to identify highly divergent RNA viruses. We developed a deep learning algorithm, termed LucaProt, to discover highly divergent RNA-dependent RNA polymerase (RdRP) sequences in 10,487 metatranscriptomes generated from diverse global ecosystems. LucaProt integrates both sequence and predicted structural information, enabling the accurate detection of RdRP sequences. Using this approach we identified 161,979 potential RNA virus species and 180 RNA virus supergroups, including many previously poorly studied groups, as well as RNA virus genomes of exceptional length (up to 47,250 nucleotides) and genomic complexity. A subset of these novel RNA viruses were confirmed by RT-PCR and RNA/DNA sequencing. Newly discovered RNA viruses were present in diverse environments, including air, hot springs and hydrothermal vents, and both virus diversity and abundance varied substantially among ecosystems. This study advances virus discovery, highlights the scale of the virosphere, and provides computational tools to better document the global RNA virome. In briefA deep learning algorithm (LucaProt) that integrates both sequence and predicted structural information was employed to identify highly divergent RNA viral "dark matter" in 10,487 metatranscriptomes from diverse global ecosystems. A total of 161,979 potential RNA virus species and 180 RNA virus supergroups was unveiled using this AI approach, including many understudied groups.

microbiology↗

The novel roles of bovine milk-derived exosomes on skin anti-aging

Exosomes are small vesicles released from cells and present in various mammal biological fluids, such as bovine milk, which worked for skin care for many years besides dairy. In addition, Exosomes were regarded as a vehicle for intercellular communication. Therefore, we aimed to investigate the novel roles of bovine milk-derived exosomes (MK-Exo) on human skin anti-aging. Purified MK-Exo can be directly uptake by the keratinocytes and fibroblast in vitro and upregulate the expression of the natural factors related to skin moisturizing, including Filaggrin (FLG), Aquaporin 3 (AQP3), CD44 in the keratinocytes and hyaluronidase (HAS2) in the fibroblast, and MK-Exo promoted the cell migration of the fibroblast, while rescue its expression of type I collagen (Col I), type III collagen (Col III) after ultraviolet radiation. Furthermore, the phototoxicity test, photoallergy test, repeated skin irritation test, skin allergy test, and patch test confirm the safety of MK-Exo on the skin. Finally, the roles of MK-Exo in preserving moisture and anti-wrinkle were also identified in humans. Then, MK-Exo was smeared on the facial skin of 31 female volunteers twice a day for 28 days, and the functions were evaluated following the safety assessment in vivo. These studies reveal the novel roles of bovine milk-derived exosomes in human skin aging, which opens a new way of skin care.

cell biology↗

Social Behavior Atlas: A computational framework for tracking and mapping 3D close interactions of free-moving animals

The study of social behaviors in animals is essential for understanding their survival and reproductive strategies. However, accurately tracking and analyzing the social interactions of free-moving animals has remained a challenge. Existing multi-animal pose estimation techniques suffer from drawbacks such as the need for extensive manual annotation and difficulty in discriminating between similar-looking animals in close social interactions. In this paper, we present the Social Behavior Atlas (SBeA), a novel computational framework that solves these challenges by employing a deep learning-based video instance segmentation model, 3D pose reconstruction, and unsupervised dynamic behavioral clustering. SBeA framework also involves a multi-camera setup to prevent occlusion, and a novel approach to identify individual animals in close social interactions. We demonstrate the effectiveness of SBeA in tracking and mapping the 3D close interactions of free-moving animals using the example of genetic mutant mice, birds, and dogs. Our results show that SBeA is capable of identifying subtle social interaction abnormalities, and the models and frameworks developed can be applied to a wide range of animal species. SBeA is a powerful tool for researchers in the fields of neuroscience and ecology to study animal social behaviors with a high degree of accuracy and reliability.

neuroscience↗

A novel purity analysis method of bovine milk-derived exosomes by two-dimensional ultra-performance liquid chromatography

Exosomes have been implicated in many biological processes as intercellular communication carriers. Because exosomes are increasingly explored as natural vehicles for cell and gene therapies, and drug delivery applications, it is critical to have high-quality samples. Protein:particle ratio, ELISA, western blotting, polymerase chain reaction, and size-exclusion high-performance liquid chromatography are the main methods that have been extensively applied to analyze exosomes purity in recent years. However, there is currently no well-established method that is convenient for routine quality analysis of small-size impurities in exosomes samples. Here, a size-exclusion high-performance liquid chromatography (SE-HPLC), an ion-exchange high-performance liquid chromatography (IEX-HPLC), and a novel two-dimensional high-performance liquid chromatography (2D-HPLC) method were used to detect the purity of bovine milk-derived exosomes with different processes of exosome isolation in detail. The results showed that the 2D-HPLC method could enhance the accuracy of detecting exosomal purity with higher precision and accuracy of instrumental, reduced personal error and experimental cost, shortened analysis time greatly, and more automation. The 2D-HPLC method is rapid, exhibits high selectivity, and has good sensitivity, thus making it well-suited for application in the pharmaceutical and toxicological analysis of exosomes.

biochemistry↗

A toolkit for converting Gal4 into LexA and Flippase transgenes in Drosophila

Drosophila has been a powerful model system for biological studies due to the wide range of genetic tools established for it. Among these tools, Gal4 is the most abundant, offering unparalleled tissue- and developmental stage-specificity for gene manipulation. In comparison, other genetic reagents are far fewer in choices. Here we present a genetic toolkit for converting Gal4 strains into LexA and Flippase transgenes through simple genetic crosses and fluorescence screening. We demonstrate the proof-of-principle by converting ten Gal4 lines that exhibit diverse tissue specificities and examined the activity patterns of the converted LexA and Flippase lines. Gal4-to-LexA and Flp conversion is fast and convenient and should greatly expand the choices of LexA and Flp for binary expression and FRT-based mosaic analysis, respectively, in Drosophila.

genetics↗

An oral vaccine for SARS-CoV-2 RBD mRNA-bovine milk-derived exosomes induces a neutralizing antibody response in vivo

The severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) that causes the coronavirus disease 2019 (COVID-19) has presented numerous challenges to global health. The vaccines, including lipid-based nanoparticle mRNA, inactivated virus and recombined protein, have been used to prevent SARS-CoV-2 infections in clinics and are immensely helpful against the epidemic. Here, we first present an oral mRNA vaccine based on bovine milk-derived exosomes (milk-exos), which encodes the SARS-CoV-2 receptor binding domain (RBD) as an immunogen. The results indicated that RBD mRNA delivered by milk-derived exosomes can produce secreted RBD peptide in 293 cells in vitro and stimulated neutralizing antibodies against RBD in mice. These results indicated that bovine milk-derived exosome-based mRNA vaccine could serve as a new strategy for preventing SARS-CoV-2 infection. Meanwhile, it also can work as a new oral delivery system for mRNA. One Sentence SummaryOral SARS-CoV-2 mRNA vaccine based on bovine milk-derived exosomes can stimulate neutralizing antibodies in mice.

immunology↗

The nutrient-sensing GCN2 signaling pathway is essential for circadian clock function by regulating histone acetylation under amino acid starvation

Circadian clocks are evolved to adapt to the daily environment changes under different conditions. The ability to maintain circadian clock functions in response to various stress and perturbations is important for organismal fitness. Here, we show that the nutrient sensing GCN2 signaling pathway is required for robust circadian clock function under amino acid starvation in Neurospora. The deletion of GCN2 pathway components disrupts rhythmic transcription of clock gene frq by suppressing WC complex binding at the frq promoter due to its reduced histone H3 acetylation levels. Under amino acid starvation, the activation of GCN2 kinase and its downstream transcription factor CPC-1 establish a proper chromatin state at the frq promoter by recruiting the histone acetyltransferase GCN-5. The arrhythmic phenotype of the GCN2 kinase mutants under amino acid starvation can be rescued by inhibiting histone deacetylation. Finally, genome-wide transcriptional analysis indicates that the GCN2 signaling pathway maintains robust rhythmic expression of metabolic genes under amino acid starvation. Together, these results uncover an essential role of GCN2 signaling pathway in maintaining robust circadian clock function in response to amino acid starvation and the importance of histone acetylation at the frq locus in rhythmic gene expression.

genetics↗