Biology subjects

Yan, F.

Publications and source records attributed to Yan, F..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Towards accurate, reference-free differential expression: A comprehensive evaluation of long-read de novo transcriptome assembly

Long-read RNA sequencing has significantly advanced transcriptomics by enabling the full length of transcripts to be assessed. However, current analysis methods often depend on a high-quality reference genome and gene annotation. Recently, de novo assembly methods have been developed to utilise long-read data in cases where a reference genome is unavailable, such as in non-model organisms. Despite the potential of these tools, there remains a lack of benchmarking and established protocols for optimal reference-free, long-read transcriptome assembly and differential expression analysis. Here, we comprehensively evaluate the current state-of-the-art long-read de novo transcriptome assembly tools, RATTLE, RNA-Bloom2 and isONform, and compare their performance to one of the leading short-read assemblers, Trinity. We assess various metrics, including assembly quality and computational efficiency, across a range of datasets, which include simulated data and spike-in sequin transcripts, where ground truth is known, and real data from human and pea (Pisum sativum) samples, using a reference-based approach to define truth. To represent contemporary analysis scenarios, the datasets cover depths from 6 million to 60 million reads, Oxford Nanopore Technologies (ONT) cDNA, ONT direct RNA and Pacific Biosciences (PacBio) 10x single-cell sequencing. Critically, we assessed the downstream impact of assembly choice on the detection of differential gene and transcript expression. Our results confirm that long reads generate longer assembled transcripts than short-reads for reference-free analysis, though limitations remain compared to reference-guided approaches, and suggest scope for improved accuracy and reduced redundancy. Of the de novo pipelines, RNA-Bloom2, coupled with Corset for transcript clustering, was the best performing in terms of both accuracy and computational efficiency. Our findings offer guidance when selecting the most effective strategy for long-read differential expression analysis, when a high-quality reference genome is unavailable.

bioinformatics↗

bioRxiv2024

Proximity proteomics provides a new resource for exploring the function of Afadin and the complexity of cell-cell adherens junctions

The network of proteins at the interface between cell-cell adherens junctions and the actomyosin cytoskeleton provides robust yet dynamic connections that facilitate cell shape change and motility. While this was initially thought to be a simple linear connection via classic cadherins and their associated catenins, we now have come to appreciate that many more proteins are involved, providing robustness and mechanosensitivity. Defining the full network of proteins in this network remains a key objective in our field. Proximity proteomics provides a means to define these networks. Mammalian Afadin and its Drosophila homolog Canoe are key parts of this protein network, facilitating diverse cell shape changes during gastrulation and other events of embryonic morphogenesis. Here we report results of several proximity proteomics screens, defining proteins in the neighborhood of both the N- and C-termini of mammalian Afadin in the premier epithelial model, MDCK cells. We compare our results with previous screens done in other cell types, and with proximity proteomics efforts with other junctional proteins. These reveal the value of multiple screens in defining the full network of neighbors and offer interesting insights into the overlap in protein composition between different epithelial cell junctions. Summary StatementAfadin BioID reveals new adherens junction proteins.

cell biology↗

bioRxiv2024

SARS-CoV-2 JN.1 reveals attenuated pathogenicity and airborne transmission

JN.1 is a subvariant of SARS-CoV-2 Omicron BA.2.86 lineage that was predominant worldwide in early 2024, of which the in vivo characteristics are largely unknown. Our results demonstrated that the replication of JN.1 was more efficient than that of the parental BA.2 in Vero cells, which demonstrated low dependence on TMPRSS2. Compared to Omicron variants BA.2 and XBB EG.5.1, JN.1 replicated less efficiently in hACE2 mouse lungs of which the intranasal infection was not lethal to hACE2 mice and led to weaker immune dysregulation. On a more sensitive, aged hACE2 hamster model, JN.1 led to a lower mortality rate and no weight loss, corresponding well with the low preference in lower airways. Lower amounts of viruses in nasal washes and exhaled aerosols were detected in JN.1 infected wildtype hamsters than EG.5.1, and consistently, JN.1 also exhibited largely reduced airborne transmission. Moreover, the poor transmission was also clearly demonstrated even by using hamsters expressing hACE2 receptors in the whole airway. Thus both pathogenicity and airborne transmission of JN.1 were demonstrated to be largely attenuated. ImportanceCurrently, SARS-CoV-2 JN.1 and its subvariants have fully replaced the previous dominant XBB lineage around the world. Although the strong immune evasion of JN.1 has been distinctly revealed, its in vivo pathogenicity and airborne transmission remained unclear. By using multiple Omicron-sensitive rodent models, our findings demonstrated that the pathogenicity of JN.1 was largely attenuated. The weak airborne transmission of JN.1 in wildtype and hACE2 hamsters was consistent with the reported relative lower transmissibility in human, and the using of airway-expressing hACE2 hamsters ulteriorly eliminates the potential bias in viral transmission studies induced by receptor divergence between animal models and human. These findings uncover the in vivo virological characteristics of SARS-CoV-2 novel lineage, providing insights for communicable disease control.

microbiology↗

bioRxiv2024

An mTOR-Tfeb-Fabp7a signaling axis can be harnessed to ameliorate bag3 cardiomyopathy in adult zebrafish

Dysregulated proteostasis in cardiomyocytes is an important pathological event in BAG3 cardiomyopathy, which can be repaired by inhibiting mechanistic target of rapamycin (mTOR) for cardioprotective effects. Here, we aimed to uncover additional pathological events and therapeutic target genes via leveraging zebrafish genetics. We first assessed transcription factor EB (tfeb), a candidate gene that encodes a direct downstream phosphorylation target of mTOR signaling. We found that cardiomyocyte-specific transgenic overexpression of tfeb (Tg[cmlc2:tfeb]) is sufficient to repair defective proteostasis, attenuate accelerated cardiac senescence, a previously unrecognized phenotype in the bag3 cardiomyopathy model, and rescue cardiac dysfunction. Next, we compared cardiac transcriptomes between the Tg(cmlc2:tfeb) transgenic fish and the mtorxu015/+ mutant, and tested 4 commonly downregulated lipodystrophy genes using an F0-based genetic assay. We found that inhibition of the fatty acid binding protein a (fabp7a) gene, but not the other 3 genes, exerts therapeutic effects on bag3 cardiomyopathy. Conversely, fabp7a expression is elevated in bag3 cardiomyopathy model and cardiomyocyte-specific overexpression of fabp7a resulted in dysregulated proteostasis, accelerated cardiac senescence, as well as cardiac dysfunction. Together, these genetic studies in zebrafish uncovered Fabp7a activation and accelerated cardiac senescence as important pathological events in bag3 cardiomyopathy. The mTOR-Tfeb-Fabp7a signaling axis can be harnessed to repair these pathological changes and exert cardioprotective effects.

genetics↗

bioRxiv2024

Efficient in situ epitope tagging of rice genes by nuclease-mediated prime editing

In situ epitope tagging is crucial for probing gene expression, protein localization, and the dynamics of protein interactions within their natural cellular context. However, the practical application of this technique in plants presents considerable hurdles. Here, we comprehensively explore the potential of the CRISPR/Cas nuclease-mediated prime editing and different DNA repair pathways in epitope tagging of endogenous rice genes. We find that SpCas9 nuclease/microhomology-mediated end joining (MMEJ)-based prime editing strategy (termed NM-PE) facilitates more straightforward and efficient gene tagging compared to the conventional and other derivative PE method. Furthermore, the PAM-flexible SpRY and ScCas9 nucleases-based prime editors have been engineered and implemented for the tagging of endogenous genes with diverse epitopes, significantly broadening the applicability of NM-PE in rice. Moreover, NM-PE has been successfully adopted in simultaneous tagging of OsMPK1 and OsMPK13 in rice plants with c-Myc and HA tags, respectively. Taken together, our results indicate great potential of the NM-PE toolkit in the targeted gene tagging for Rice Protein Tagging Project, gene function study and genetic improvement.

plant biology↗

bioRxiv2024

Haploid-phased chromosomal telomere to telomere genome assembly of Uncaria rhynchophylla accelerating gene mining on the biosynthesis of medicinal alkaloids

Recorded traditionary medicinal plants contain important resources, including many natural medicinal alkaloids, for new medicine discovery and development. Uncaria genus is such a woody plant, with a high medicinal value in alkaloids, e.g. (iso)rhynchophylline. Natural alkaloids contents usually vary between germplasms and are affected by the growth environment, which requires a genomics solution to understand the genetic and environmental factors that influence alkaloid production in more detail. Here, we have dissected the haploid-resolved chromosomal T2T genome assembly of Uncaria rhynchophylla with a size of [~]634 Mb and contig N50 of 26 Mb using PacBio HiFi long-reads and Hi-C and anchored the contigs on 22 pairs of confirmed chromosomes. This genome contains 56% repeat sequences and [~]2,9000 protein-encoding genes. U. rhynchophylla diverged from a common ancestor shared with Coffea around 20 million years ago and contains expanded and contracted gene families associated with secondary metabolites and plant-associated defenses. We constructed the pathway for (iso)rhynchophylline biosynthesis with genes mined from the genome and comparative transcriptomes. 53 alkaloids out of 2,578 metabolites were identified in (iso)rhynchophylline biosynthesis, where eight differentially expressed genes were the key for regulating the catalytic steps leading to alkaloid abundance difference between tissues. The chromosome-level genome and pathways of (iso)rhynchophylline constructed in this study provide a genetic basis and guidance for further breeding improvements and the development of pharmaceutical alkaloids.

genomics↗

bioRxiv2024

Virological characteristics of SARS-CoV-2 Omicron BA.5.2.48

With the prevalence of sequentially-emerged sublineages including BA.1, BA.2 and BA.5, SARS-CoV-2 Omicron infection has transformed into a regional epidemic disease. As a sublineage of BA.5, the BA.5.2.48 outbreak and evolved into multi-subvariants in China without clearly established virological characteristics, especially the pathogenicity. Though reduced airborne transmission and pathogenicity of former Omicron sublineages have been revealed in animal models, the virological characteristics of BA.5.2.48 was unidentified. Here, we evaluated the in vitro and in vivo virological characteristics of two isolates of the prevalent BA.5.2.48 subvariant, DY.2 and DY.1.1 (a subvariant of DY.1). DY.2 replicates more efficiently than DY.1.1 in HelahACE2+ cells and Calu-3 cells. The A570S mutation (of DY.1) in a normal BA.5 spike protein (DY.2) leads to a 20% improvement in the hACE2 binding affinity, which is slightly reduced by a further K147E mutation (of DY.1.1). Compared to the normal BA.5 spike, the double-mutated protein demonstrates efficient cleavage and reduced fusogenicity. BA.5.2.48 demonstrated enhanced airborne transmission capacity in hamsters than BA.2. The pathogenicity of BA.5.2.48 is greater than BA.2, as revealed in K18-hACE2 rodents. Under immune selection pressure, DY.1.1 shows stronger fitness than DY.2 in hamster turbinates. Thus the outbreaking prevalent BA.5.2.48 multisubvariants exhibites divergent virological features. ImportanceOmicron continues to circulate and evolves novel sublineages with indistinguishable pathogenicity and transmission. Therefore humanized Omicron-sensitive animal models must be applied to evaluate the virological characteritics and antiviral therapeutics. By using multiple models including the Omicron-lethal H11-K18-hACE2 rodents, BA.5.2.48 revealed higher pathogenicity in the novel H11-K18-hACE2 rodent models than the previously epidemic BA.2, and thus the models are more adapted to Omicron studies. Moreover, the regional outbreaking of BA.5.2.48 promotes the multidirectional evolution of its subvariants, gaining either enhanced pathogenicity or a fitness in upper airways which is associated with higher transmission, highlighting the importance of surveillance and virological studies on regionally endemic sublineages which represents the short-run evolutionary direction of Omicron.

microbiology↗

bioRxiv2024

BMP9 and BMP10 coordinate liver cellular crosstalk to maintain liver health

The liver is the largest solid organ in the body and is primarily composed of HCs, ECs, KCs, and HSCs, which spatially interact and cooperate with each other to maintain liver homeostasis. However, the complexity and molecular mechanisms underlying the crosstalk between these different cell types remain to be revealed. Here, we generated mice with conditional deletion of Bmp9/10 in different liver cell types and demonstrated that HSCs were the major source of BMP9 and BMP10 in the liver. Using transgenic ALK1 (receptor for BMP9/10) reporter mice, we found that ALK1 is expressed on KCs and ECs other than HCs and HSCs, and BMP9/10 secreted by HSCs promotes the differentiation of KCs and ECs and maintain their identity. Pdgfb expression was significantly upregulated in KCs and ECs after BMP9 and BMP10 deletion, ultimately leading to HSCs activation and liver fibrosis. ECs express several angiocrine factors, such as BMP2, BMP6, Wnt2 and Rspo3, to regulate hepatocyte iron metabolism and metabolic zonation. We found that these angiocrine factors were significantly decreased in ECs from Bmp9/10HSC-KO mice, which further resulted in liver iron overload and disruption of HC zonation. In summary, we demonstrated that HSCs play a central role in mediating liver cell-cell crosstalk via the production of BMP9/10, highlighting the important role of intercellular interaction in organ development and homeostasis.

cell biology↗

bioRxiv2024

Development of a cell-based DIFF-rGFP assay system for generalized discovery of viral protease Inhibitors

1.Viral protease is an attractive target for antiviral therapeutics, but current viral protease inhibitor screening methods still need to be improved. Here, we systematically investigated the sites that may accommodate exogenous short peptides within Enhanced Green Fluorescent Protein (EGFP) and constructed a series of recombinant green fluorescent proteins (rGFPs). Meanwhile, a cell-based, simple and reliable assay system named DIFF-rGFP was developed relying on the co-expression of rGFP and the protease for protease inhibitor screening with the example of 3CLpro, in which the fluorescence intensity increases with the action of the inhibitor. The DIFF-rGFP assay avoided the requirement of a higher biosafety lab and can be performed in a high-throughput manner. For proof of concept, we demonstrated this method to discover novel inhibitors against SARS-CoV-2. We believe the proposed method, in combination with available drug libraries, may accelerate the identification of novel antivirals.

molecular biology↗

bioRxiv2023

Discovery and characterization of highly potent and selective covalent inhibitors of SARS-CoV-2 PLpro

Coronavirus infections, such as the global COVID-19 pandemic, have had a profound impact on many aspects of our daily life including working style, economy, and the healthcare system. To prevent the rapid viral transmission and speed up recovery from the infection, many academic organizations and industry research labs have conducted extensive research on discovering new therapeutic options for SARS-CoV-2. Among those efforts, RNA-dependent RNA polymerase (RdRp) inhibitors such as Remdesivir, Molnupiravir and 3CLpro inhibitor such as Nirmatrelvir (Paxlovid) have been widely used as the therapeutic options. Given the recent emergence of several new variants that caused a resurgence of the virus, it would be beneficial to discover more diverse therapeutic options with novel anti-viral mechanisms. In this regard, PLpro has been highlighted since it, along with 3CLpro, is one of the two most important proteases that are required for SARS-CoV-2 viral processing. While 3CLpro inhibitors were extensively investigated in the light of Emergency Use Authorizations of Nirmatrelvir, PLpro inhibitors have not been thoroughly investigated even preclinically. Thus, discovery efforts on antivirals acting against PLpro will be valuable. PLpro inhibitors may exert their activity by inhibiting viral replication and enhancing the host defense system through blocking virus-induced cell signaling events for evading host immune response. In this study, we report the discovery and development of two covalent irreversible PLpro inhibitors, HUP0109 and its deuterated analog DX-027, out of our quest for novel anti-COVID 19 therapeutic agents for the past two and half years. HUP0109 selectively targets the viral catalytic cleft of PLpro and covalently modifies its active site cysteine residue (C111). Promising results from preclinical evaluation suggest that DX-027 can be developed as a potential COVID-19 treatment.

pharmacology and toxicology↗

bioRxiv2022

The dynamic nature of neurotensin receptor 1 (NTS1) allostery and signaling bias

The neurotensin receptor 1 (NTS1) is a G protein-coupled receptor (GPCR) with promise as a drug target for the treatment of pain, schizophrenia, obesity, addiction, and various cancers. A detailed picture of the NTS1 structural landscape has been established by X-ray crystallography and cryo-EM and yet, the molecular determinants for why a receptor couples to G protein versus arrestin transducers remain poorly defined. We used 13C{varepsilon}H3-methionine NMR spectroscopy to show that phosphatidylinositol-4,5-bisphosphate (PIP2) promotes transducer complexation not by dramatically altering the receptor structure but by strengthening long-range allosteric connections, in the form of correlated conformational kinetics, between the orthosteric pocket and highly-conserved activation motifs. {beta}-arrestin-1 further remodels the receptor ensemble by reducing conformational exchange kinetics for a subset of resonances, whereas G protein coupling has little to no effect on the rate. A {beta}-arrestin biased allosteric modulator transforms the NTS1:G protein complex into a concatenation of substates, without triggering transducer dissociation, suggesting that it may function by stabilizing signaling incompetent G protein conformations such as the non-canonical state. Together, our work demonstrates the importance of kinetic information to a complete picture of the GPCR activation landscape.

biochemistry↗

bioRxiv2022

Single-cell multi-omics decodes regulatory programs during development of mouse secondary palate

The abnormal perturbation in gene regulation during palatogenesis may lead to cleft palate, a major congenital birth defect in humans and mice. However, a comprehensive multi-omic map of the developing secondary palate at single-cell resolution is lacking. In this study, we performed single-cell multiome sequencing and profiled chromatin accessibility and gene expression simultaneously within the same cells (n = 36,154) isolated from mouse secondary palate across embryonic days (E) 12.5, E13.5, E14.0, and E14.5. Application of optimal transport reconstructed five trajectories, representing continuous differentiation of multipotent cells into different subpopulations in later stages. By linking open chromatin signals to gene expression changes, we discovered a list of lineage-determining transcription factors, such as Shox2 for the anterior and Dlx1/2 for the posterior palatal mesenchymal trajectories. In conclusion, this study charted epigenetic and transcriptional dynamics during palatogenesis, which provides a valuable resource for the community and facilitate future research in cleft palate. HighlightsO_LIThe first report on building a single-cell multi-omics atlas with joint chromatin accessibility and gene expression measurements from the same cells during the development of mouse secondary palate. C_LIO_LIApplication of optimal transport calculated fate probabilities to different terminal states and recovered continuous landscapes during mouse secondary palate development. C_LIO_LIBy linking cis-regulatory DNA elements to target genes, we characterized a series of transcription factors governing the differentiation of cranial neural crest-derived multipotent cells to the anterior and posterior palatal mesenchymal trajectories, respectively. C_LIO_LITranscription factors Shox2 and Dlx1/2 exhibited top regulatory roles for the anterior and posterior palatal mesenchymal trajectories, respectively, showing significant enrichment in both motif accessibility and gene expression. C_LI

developmental biology↗

bioRxiv2022

CRISPR/FnCas12a-mediated efficient multiplex and iterative genome editing in bacterial plant pathogens without donor DNA templates

CRISPR-based genome editing technology is revolutionizing prokaryotic research, but it has been rarely studied in bacterial plant pathogens. Here, we have developed a targeted genome editing method with no requirement of donor templates for convenient and efficient gene knockout in Xanthomonas oryzae pv. oryzae (Xoo), one of the most important bacterial pathogens on rice, by employing the heterogenous CRISPR/Cas12a from Francisella novicida and NHEJ proteins from Mycobacterium tuberculosis. FnCas12a nuclease generated both small and large DNA deletions at the target sites as well as it enabled multiplex genome editing, gene cluster deletion and plasmid cure in the Xoo PXO99A strain. Accordingly, a non-TAL effector-free polymutant strain PXO99AD25E, which lacks all 25 Xop genes involved in Xoo pathogenesis, has been engineered through iterative genome editing. Whole-genome sequencing analysis indicated that FnCas12a did not have a noticeable off-target effect. In addition, we revealed that these strategies are also suitable for targeted genome editing in another bacterial plant pathogen Pseudomonas syringae pv. tomato (Pst). We believe that our bacterial genome editing method will greatly expand the CRISPR study on microorganisms and advance our understanding of the physiology and pathogenesis of Xoo.

microbiology↗

bioRxiv2022

Ligands tune the local and global motions of neurotensin receptor 1 (NTS1): a DFT-guided solution NMR analysis

Unlike many signaling proteins that function as binary switches between on and off states, G protein-coupled receptors (GPCRs) exhibit basal activity that can be increased or decreased by numerous ligands. A given receptor can recognize multiple ligands, allosteric modulators, and transducers to create a complex free energy landscape. Many of the lowest energy states have been captured by static structural techniques while detailing the wells widths, metastable states, and the transition between them, is still in its infancy. Nuclear magnetic resonance (NMR) spectroscopy can monitor the structure and dynamics of GPCR ensembles across fifteen orders-of-magnitude, but technical challenges have limited its application to super-microsecond timescales. Focusing on a prototypical peptide-binding GPCR, the neurotensin receptor 1 (NTS1), we employed NMR and density functional theory (DFT) to probe global sub-nanosecond motions. The near random coil chemical shifts of the apo receptor produced a poor correlation with theoretical predictions that may indicate a high degree of conformational averaging in solution, a crystallization artifact, or both. Whereas orthosteric agonists and antagonists both rigidified the receptor, but to varying degrees, which suggests conformational entropy differentially contributes to their respective pharmacology. The strong correlations of observed and theoretical chemical shifts lend confidence to interpreting spectra in terms of local structure, methyl dihedral angle geometry, and pico-second timescale transitions. Together, our results suggest a role for sub-nanosecond dynamics and conformational entropy in GPCR ligand discrimination.

biophysics↗

bioRxiv2022

Widespread of horizontal gene transfer regions in eukaryotes

Horizontal gene transfer (HGT) is the transfer of genetic material between distantly related organisms. While most genes in prokaryotes can be horizontally transferred, HGT events in eukaryotes are considered as rare, particularly in mammals. Here we reported the identification of HGT regions (HGTs), which are genomic sequence fragments indicating the occurrence of HGT events, in human, mouse, cow, lizard, frog, zebrafish, fruit fly, nematode, Arabidopsis and yeast. By comparing the genomes of these 10 representative eukaryotes with 1,496 eukaryotic genomes, 16,098 bacteria and 11,695 viruses, we found between 10 and 243 non-redundant HGTs per species, and most of these HGTs were previously unknown. These HGTs have transformed their host genomes with various numbers of copies and have impacted hundreds, even thousands of genes. We listed several examples of HGTs and proposed some possible routes that HGT events occurred. Further analysis showed that the majority of the 1,496 eukaryotes with full length genome sequences also contain HGTs. Our findings reveal that HGT is widespread in eukaryotic genomes, and HGT is a ubiquitous driver of genome evolution for eukaryotes.

genomics↗

bioRxiv2022

Mechanical vibration modulates regional cerebral blood flow and biomechanical co-variance network in a frequency-dependent manner

Human brain experiences vibration of certain frequency during various physical activities such as vehicle transportation and machine operation or accidents, which may cause traumatic brain injury or other brain diseases. However, little is known about what happened to brain after vibration stimuli. Here, with a custom-built electromagnetic actuator, vibration was induced in the brain while cerebral blood flow (CBF) and brain stiffness were measured at 20, 30, 40 Hz for 52 healthy volunteers. With increasing frequency, multiple regions of the brain showed increasingly reduced CBF, while the size of such regions also expanded. The vibration-induced CBF reduction regions largely fell inside the brains default mode network (DMN), with about 58 or 46 % overlap at 30 or 40 Hz, respectively. By establishing a biomechanical co-variance network based on tissue stiffness, analysis of small-world properties and modularity showed an increased disruption of the network with increased frequency. These findings demonstrate frequency-dependent features of vibration modulation to brain. Furthermore, the overlap between CBF reduction regions and DMN, and the vibration-induced decrease of biomechanical network connections suggest a interweaved relationship between blood flow, tissue stiffness, and cognitive functions. These may provide critical insights into the mechanical stimulus to brain and vibration-induced brain pathologies.

neuroscience↗

bioRxiv2022

Nonlinear effect of light intensity on normal axial development of rhesus monkeys

PurposeTo investigate the effects of different indoor lighting intensity (500 lx, 750 lx and 1,000 lx) on normal ocular axial length growth by using juvenal rhesus monkeys. MethodsTwenty-four juvenile monkeys were exposed continuously to normal intensity light (NIL, 500 lx, n=16), medium intensity light (MIL, 750 lx, n=8) and high intensity light (HIL, 1 000 lx, n=8), with a same CCT value (about 3000 K) for 246 days. Axial length, anterior chamber depth, corneal curvature radius were measured at about a monthly interval. ResultsAfter 246 days of light exposure, the growth of axial length of the MIL group (750 lx) were 0.151 {+/-} 0.081 mm and 0.139 {+/-} 0.070 mm in the right and left eyes, respectively, and significantly larger in comparison with the NIL group (500lx, OD: 0.068 {+/-} 0.055 mm, OS: 0.074 {+/-} 0.057 mm) and the HIL group (1000lx,OD:0.063 {+/-} 0.093 mm, OS: 0.084 {+/-} 0.052 mm) monkeys. This effect was stable and robust during the whole experimental period. ConclusionThe effects of different intensity lighting on normal ocular axial development was not linear as most people currently think. We must be cautious when it comes to elevate light intensity in classrooms. Whether this conclusion is correct under lights of other CCT value needs further study.

developmental biology↗

bioRxiv2022

GhCO and GhCRY1 accelerate floral meristem initiation in response to blue light to shorten cotton breeding

The shoot apical meristem (SAM) is a special category of tissue with pluripotency that forms new organs and individuals, especially floral individuals. However, little is known about the fate of cotton SAMs as a tunica corpus structure. Here, we demonstrate that cotton SAM fate decisions depend on light signals and circadian rhythms, and the genes GhFKF1, GhGI, GhCRY1 and GhCO were responsible for SAM fate decisions and highlighted via RNA sequencing (RNA-seq) analysis of different cotton cultivars, as confirmed by genetic analysis via the CRISPR-Cas9 system. In situ hybridization (ISH) analysis showed that the GhCO gene, induced by a relatively high blue light proportion, was highly upregulated during the initiation of floral meristems (FMs). Further blue light treatment analysis showed that the transition from vegetative to reproductive growth of SAM was promoted by a high proportion of blue light, coupled with high expression of the blue light-responsive genes GhCO and GhCRY1. Taken together, our study suggests that blue light signalling plays a key role in the fate decision of cotton SAM. These results provide a strategy to regulate the SAM differentiation of cotton by using the CRISPR-Cas9 system to change the ratio of red and blue light absorption to breed early-maturity cotton. One-sentence summaryThe SAM differentiation especially the initiation of floral meristem of upland cotton were mediated by genes GhCO and GhCRY1 which in response to blue light.

developmental biology↗