Regenerative Metaplastic Clones in COPD Lung Drive Inflammation and Fibrosis.

Chronic obstructive pulmonary disease (COPD) is a progressive condition of chronic bronchitis, small airway obstruction, and emphysema that represents a leading cause of death worldwide. While inflammation, fibrosis, mucus hypersecretion, and metaplastic epithelial lesions are hallmarks of this disease, their origins and dependent relationships remain unclear. Here we apply single-cell cloning technologies to lung tissue of patients with and without COPD. Unlike control lungs, which were dominated by normal distal airway progenitor cells, COPD lungs were inundated by three variant progenitors epigenetically committed to distinct metaplastic lesions. When transplanted to immunodeficient mice, these variant clones induced pathology akin to the mucous and squamous metaplasia, neutrophilic inflammation, and fibrosis seen in COPD. Remarkably, similar variants pre-exist as minor constituents of control and fetal lung and conceivably act in normal processes of immune surveillance. However, these same variants likely catalyze the pathologic and progressive features of COPD when expanded to high numbers.

Cloning of Macaque Monkeys by Somatic Cell Nuclear Transfer.

Generation of genetically uniform non-human primates may help to establish animal models for primate biology and biomedical research. In this study, we have successfully cloned cynomolgus monkeys (Macaca fascicularis) by somatic cell nuclear transfer (SCNT). We found that injection of H3K9me3 demethylase Kdm4d mRNA and treatment with histone deacetylase inhibitor trichostatin A at one-cell stage following SCNT greatly improved blastocyst development and pregnancy rate of transplanted SCNT embryos in surrogate monkeys. For SCNT using fetal monkey fibroblasts, 6 pregnancies were confirmed in 21 surrogates and yielded 2 healthy babies. For SCNT using adult monkey cumulus cells, 22 pregnancies were confirmed in 42 surrogates and yielded 2 babies that were short-lived. In both cases, genetic analyses confirmed that the nuclear DNA and mitochondria DNA of the monkey offspring originated from the nucleus donor cell and the oocyte donor monkey, respectively. Thus, cloning macaque monkeys by SCNT is feasible using fetal fibroblasts.

Systemic Human ILC Precursors Provide a Substrate for Tissue ILC Differentiation.

Innate lymphoid cells (ILCs) represent innate versions of T helper and cytotoxic T cells that differentiate from committed ILC precursors (ILCPs). How ILCPs give rise to mature tissue-resident ILCs remains unclear. Here, we identify circulating and tissue ILCPs in humans that fail to express the transcription factors and cytokine outputs of mature ILCs but have these signature loci in an epigenetically poised configuration. Human ILCPs robustly generate all ILC subsets in vitro and in vivo. While human ILCPs express low levels of retinoic acid receptor (RAR)-related orphan receptor C (RORC) transcripts, these cells are found in RORC-deficient patients and retain potential for EOMES+ natural killer (NK) cells, interferon gamma-positive (IFN-γ+) ILC1s, interleukin (IL)-13+ ILC2s, and for IL-22+, but not for IL-17A+ ILC3s. Our results support a model of tissue ILC differentiation ("ILC-poiesis"), whereby diverse ILC subsets are generated in situ from systemically distributed ILCPs in response to local environmental signals.

Neutralizing Antibody Responses to Viral Infections Are Linked to the Non-classical MHC Class II Gene H2-Ob.

Select humans and animals control persistent viral infections via adaptive immune responses that include production of neutralizing antibodies. The precise genetic basis for the control remains enigmatic. Here, we report positional cloning of the gene responsible for production of retrovirus-neutralizing antibodies in mice of the I/LnJ strain. It encodes the beta subunit of the non-classical major histocompatibility complex class II (MHC-II)-like molecule H2-O, a negative regulator of antigen presentation. The recessive and functionally null I/LnJ H2-Ob allele supported the production of virus-neutralizing antibodies independently of the classical MHC haplotype. Subsequent bioinformatics and functional analyses of the human H2-Ob homolog, HLA-DOB, revealed both loss- and gain-of-function alleles, which could affect the ability of their carriers to control infections with human hepatitis B (HBV) and C (HCV) viruses. Thus, understanding of the previously unappreciated role of H2-O (HLA-DO) in immunity to infections may suggest new approaches in achieving neutralizing immunity to viruses.

Mutations in the genes responsible for the synthesis of furan fatty acids resolve the light-induced off-odor in soybean oil.

Soybean oil is the second most produced edible vegetable oil and is used for many edible and industrial materials. Unfortunately, it has the disadvantage of 'reversion flavor' under photooxidative conditions, which produces an off-odor and decreases the quality of edible oil. Reversion flavor and off-odor are caused by minor fatty acids in the triacylglycerol of soybean oil known as furan fatty acids, which produce 3-methyl-2,4-nonanedione (3-MND) upon photooxidation. As a solution to this problem, a reduction in furan fatty acids leads to a decrease in 3-MND, resulting in a reduction in the off-odor induced by light exposure. However, there are no reports on the genes related to the biosynthesis of furan fatty acids in soybean oil. In this study, four mutant lines showing low or no furan fatty acid levels in soybean seeds were isolated from a soybean mutant library. Positional cloning experiments and homology search analysis identified two genes responsible for furan fatty acid biosynthesis in soybean: Glyma.20G201400 and Glyma.04G054100. Ectopic expression of both genes produced furan fatty acids in transgenic soybean hairy roots. The structure of these genes is different from that of the furan fatty acid biosynthetic genes in photosynthetic bacteria. Homologs of these two group of genes are widely conserved in the plant kingdom. The purified oil from the furan fatty acid mutant lines had lower amounts of 3-MND and reduced off-odor after light exposure, compared with oil from the wild-type.

Plastid terminal oxidase is required for chloroplast biogenesis in barley.

Chloroplast biogenesis is critical for crop biomass and economic yield. However, chloroplast development is a very complicated process coordinated by cross-communication between the nucleus and plastids, and the underlying mechanisms have not been fully revealed. To explore the regulatory machinery for chloroplast biogenesis, we conducted map-based cloning of the Grandpa 1 (Gpa1) gene regulating chloroplast development in barley. The spontaneous mutation gpa1.a caused a variegation phenotype of the leaf, dwarfed growth, reduced grain yield, and increased tiller number. Genetic mapping anchored the Gpa1 gene onto 2H within a gene cluster functionally related to photosynthesis or chloroplast differentiation. One gene (HORVU.MOREX.r3.2HG0213170) in the delimited region encodes a putative plastid terminal oxidase (PTOX) in thylakoid membranes, which is homologous to IMMUTANS (IM) of Arabidopsis. The IM gene is required for chloroplast biogenesis and maintenance of functional thylakoids in Arabidopsis. Using CRISPR technology and gene transformation, we functionally validated that the PTOX-encoding gene, HORVU.MOREX.r3.2HG0213170, is the causal gene of Gpa1. Gene expression and chemical analysis revealed that the carotenoid biosynthesis pathway is suppressed by the gpa1 mutation, rendering mutants vulnerable to photobleaching. Our results showed that the overtillering associated with the gpa1 mutation was caused by the lower accumulation of carotenoid-derived strigolactones (SLs) in the mutant. The cloning of Gpa1 not only improves our understanding of the molecular mechanisms underlying chloroplast biosynthesis but also indicates that the PTOX activity is conserved between monocots and dicots for the establishment of the photosynthesis factory.

Functional allele of a MATE gene selected during domestication modulates seed color in chickpea.

Seed color is one of the key target traits of domestication and artificial selection in chickpeas due to its implications on consumer preference and market value. The complex seed color trait has been well dissected in several crop species; however, the genetic mechanism underlying seed color variation in chickpea remains poorly understood. Here, we employed an integrated genomics strategy involving QTL mapping, high-density mapping, map-based cloning, association analysis, and molecular haplotyping in an inter-specific RIL mapping population, association panel, wild accessions, and introgression lines (ILs) of Cicer gene pool. This delineated a MATE gene, CaMATE23, encoding a Transparent Testa (TT) and its natural allele (8-bp insertion) and haplotype underlying a major QTL governing seed color on chickpea chromosome 4. Signatures of selective sweep and a strong purifying selection reflected that CaMATE23, especially its 8-bp insertion natural allelic variant, underwent selection during chickpea domestication. Functional investigations revealed that the 8-bp insertion containing the third cis-regulatory RY-motif element in the CaMATE23 promoter is critical for enhanced binding of CaFUSCA3 transcription factor, a key regulator of seed development and flavonoid biosynthesis, thereby affecting CaMATE23 expression and proanthocyanidin (PA) accumulation in the seed coat to impart varied seed color in chickpea. Consequently, overexpression of CaMATE23 in Arabidopsis tt12 mutant partially restored the seed color phenotype to brown pigmentation, ascertaining its functional role in PA accumulation in the seed coat. These findings shed new light on the seed color regulation and evolutionary history, and highlight the transcriptional regulation of CaMATE23 by CaFUSCA3 in modulating seed color in chickpea. The functionally relevant InDel variation, natural allele, and haplotype from CaMATE23 are vital for translational genomic research, including marker-assisted breeding, for developing chickpea cultivars with desirable seed color that appeal to consumers and meet global market demand.

GoSTR, a negative modulator of stem trichome formation in cotton.

Trichomes, the outward projection of plant epidermal tissue, provide an effective defense against stress and insect pests. Although numerous genes have been identified to be involved in trichome development, the molecular mechanism for trichome cell fate determination is not well enunciated. Here, we reported GoSTR functions as a master repressor for stem trichome formation, which was isolated by map-based cloning based on a large F2 segregating population derived from a cross between TM-1 (pubescent stem) and J220 (smooth stem). Sequence alignment revealed a critical G-to-T point mutation in GoSTR's coding region that converted codon 2 from GCA (Alanine) to TCA (Serine). This mutation occurred between the majority of Gossypium hirsutum with pubescent stem (GG-haplotype) and G. barbadense with glabrous stem (TT-haplotype). Silencing of GoSTR in J220 and Hai7124 via virus-induced gene silencing resulted in the pubescent stems but no visible change in leaf trichomes, suggesting stem trichomes and leaf trichomes are genetically distinct. Yeast two-hybrid assay and luciferase complementation imaging assay showed GoSTR interacts with GoHD1 and GoHOX3, two key regulators of trichome development. Comparative transcriptomic analysis further indicated that many transcription factors such as GhMYB109, GhTTG1, and GhMYC1/GhDEL65 which function as positive regulators of trichomes were significantly upregulated in the stem from the GoSTR-silencing plant. Taken together, these results indicate that GoSTR functions as an essential negative modulator of stem trichomes and its transcripts will greatly repress trichome cell differentiation and growth. This study provided valuable insights for plant epidermal hair initiation and differentiation research.

Mutation and sequencing-based cloning and functional studies of a rust resistance gene in sunflower (Helianthus annuus).

Rust, caused by the fungus Puccinia helianthi Schwein., is one of the most devastating diseases of sunflower (Helianthus annuus L.), affecting global production. The rust R gene R11 in sunflower line HA-R9 shows broad-spectrum resistance to P. helianthi virulent races and was previously mapped to an interval on sunflower chromosome 13 encompassing three candidate genes annotated in the XRQr1.0 reference genome assembly. In the current study, we combined ethyl methane sulfonate (EMS) mutagenesis with targeted region capture and PacBio long-read sequencing to clone the R11 gene. Sequencing of a 60-kb region spanning the R11 locus from the R11 -HA-R9 rust-resistant line and three EMS-induced susceptible mutants facilitated the identification of R11 and definition of induced mutations. The R11 gene is predicted to have a single 3996-bp open reading frame and encodes a protein of 1331 amino acids with CC-NBS-LRR domains typical of genes conferring plant resistance to biotrophic pathogens. Point mutations identified in the R11 rust-susceptible mutants resulted in premature stop codons, consistent with loss of function leading to rust susceptibility. Additional functional studies using comparative RNA sequencing of the resistant line R11 -HA-R9 and R11 -susceptible mutants revealed substantial differences in gene expression patterns associated with R11 -mediated resistance at 7 days post-inoculation with rust, and uncovered the potential roles of terpenoid biosynthesis and metabolism in sunflower rust resistance.

TAF1 is needed for the proliferation and maturation of thyroid follicle cells via Notch signaling.

Thyroid dysgenesis (TD) is the common pathogenic mechanism of congenital hypothyroidism (CH). In addition, known pathogenic genes are limited to those that are directly involved in thyroid development. To identify additional candidate pathogenetic genes, we performed forward genetic screening for TD in zebrafish, followed by positional cloning. The candidate gene was confirmed in vitro using the Nthy-ori 3.1 cell line and in vivo using a zebrafish model organism. We obtained a novel zebrafish line with thyroid dysgenesis and identified the candidate pathogenetic mutation TATA-box binding protein associated Factor 1 (taf1) by positional cloning. Further molecular studies revealed that taf1 was needed for the proliferation of thyroid follicular cells by binding to the NOTCH1 promoter region. Knockdown of TAF1 impaired the proliferation and maturation of thyroid cells, thereby leading to thyroid dysplasia. This study showed that TAF1 promoted Notch signaling and that this association played a pivotal role in thyroid development.NEW & NOTEWORTHY In our study, we obtained a novel zebrafish line with thyroid dysgenesis (TD) and identified the candidate pathogenetic mutation TATA-box binding protein associated Factor 1 (taf1). Further researches revealed that taf1 was required for thyroid follicular cells by binding to the NOTCH1 promoter region. Our findings revealed a novel role of TAF1 in thyroid morphogenesis.

A vector system for single and tandem expression of cloned genes and multi-colour fluorescent tagging in Haloferax volcanii.

Archaeal cell biology is an emerging field expected to identify fundamental cellular processes, help resolve the deep evolutionary history of cellular life, and contribute new components and functions in biotechnology and synthetic biology. To facilitate these, we have developed plasmid vectors that allow convenient cloning and production of proteins and fusion proteins with flexible, rigid, or semi-rigid linkers in the model archaeon Haloferax volcanii. For protein subcellular localization studies using fluorescent protein (FP) tags, we created vectors incorporating a range of codon-optimized fluorescent proteins for N- or C-terminal tagging, including GFP, mNeonGreen, mCherry, YPet, mTurquoise2 and mScarlet-I. Obtaining functional fusion proteins can be challenging with proteins involved in multiple interactions, mainly due to steric interference. We demonstrated the use of the new vector system to screen for improved function in cytoskeletal protein FP fusions, and identified FtsZ1-FPs that are functional in cell division and CetZ1-FPs that are functional in motility and rod cell development. Both the type of linker and the type of FP influenced the functionality of the resulting fusions. The vector design also facilitates convenient cloning and tandem expression of two genes or fusion genes, controlled by a modified tryptophan-inducible promoter, and we demonstrated its use for dual-colour imaging of tagged proteins in H. volcanii cells. These tools should promote further development and applications of archaeal molecular and cellular biology and biotechnology.

A toolbox for manipulating the genome of the major goat pathogen, Mycoplasma capricolum subsp. capripneumoniae.

Mycoplasma capricolum subspecies capripneumoniae (Mccp) is the causative agent of contagious caprine pleuropneumonia (CCPP), a devastating disease listed by the World Organisation for Animal Health (WOAH) as a notifiable disease and threatening goat production in Africa and Asia. Although a few commercial inactivated vaccines are available, they do not comply with WOAH standards and there are serious doubts regarding their efficacy. One of the limiting factors to comprehend the molecular pathogenesis of CCPP and develop improved vaccines has been the lack of tools for Mccp genome engineering. In this work, key synthetic biology techniques recently developed for closely related mycoplasmas were adapted to Mccp. CReasPy-Cloning was used to simultaneously clone and engineer the Mccp genome in yeast, prior to whole-genome transplantation into M. capricolum subsp. capricolum recipient cells. This approach was used to knock out an S41 serine protease gene recently identified as a potential virulence factor, leading to the generation of the first site-specific Mccp mutants. The Cre-lox recombination system was then applied to remove all DNA sequences added during genome engineering. Finally, the resulting unmarked S41 serine protease mutants were validated by whole-genome sequencing and their non-caseinolytic phenotype was confirmed by casein digestion assay on milk agar. The synthetic biology tools that have been successfully implemented in Mccp allow the addition and removal of genes and other genetic features for the construction of seamless targeted mutants at ease, which will pave the way for both the identification of key pathogenicity determinants of Mccp and the rational design of novel, improved vaccines for the control of CCPP.

Neq2X7: a multi-purpose and open-source fusion DNA polymerase for advanced DNA engineering and diagnostics PCR.

Thermostable DNA polymerases, such as Taq isolated from the thermophilic bacterium Thermus aquaticus, enable one-pot exponential DNA amplification known as polymerase chain reaction (PCR). However, properties other than thermostability - such as fidelity, processivity, and compatibility with modified nucleotides - are important in contemporary molecular biology applications. Here, we describe the engineering and characterization of a fusion between a DNA polymerase identified in the marine archaea Nanoarchaeum equitans and a DNA binding domain from the thermophile Sulfolobus solfataricus. The fusion creates a highly active enzyme, Neq2X7, capable of amplifying long and GC-rich DNA, unaffected by replacing dTTP with dUTP in PCR, and tolerant to various known PCR inhibitors. This makes it an attractive DNA polymerase for use, e.g., with uracil excision (USER) DNA assembly and for contamination-free diagnostics. Using a magnification via nucleotide imbalance fidelity assay, Neq2X7 was estimated to have an error rate lower than 2 ∙ 10-5 bp-1 and an approximately 100x lower fidelity than the parental variant Neq2X, indicating a trade-off between fidelity and processivity - an observation that may be of importance for similarly engineered DNA polymerases. Neq2X7 is easy to produce for routine application in any molecular biology laboratory, and the expression plasmid is made freely available.

Fine mapping of TFL, a major gene regulating fruit length in snake gourd (Trichosanthes anguina L).

Fruit length is a crucial agronomic trait of snake gourd (Trichosanthes anguina L); however, genes associated with fruit length have not been characterised. In this study, F2 snake gourd populations were generated by crossing the inbred lines, S1 and S2 (fruit lengths: 110 and 20 cm, respectively). Subsequently, bulk segregant analysis, sequencing, and fine-mapping were performed on the F2 population to identify target genes. Our findings suggest that the fruit length of snake gourd is regulated by a major-effect regulatory gene. Mining of genes regulating fruit length in snake gourd to provide a basis for subsequent selection and breeding of new varieties. Genotype-phenotype association analysis was performed on the segregating F2 population comprising 6,000 plants; the results indicate that the target gene is located on Chr4 (61,846,126-61,865,087 bp, 18.9-kb interval), which only carries the annotated candidate gene, Tan0010544 (designated TFL). TFL belongs to the MADS-box family, one of the largest transcription factor families. Sequence analysis revealed a non-synonymous mutation of base C to G at position 202 in the coding sequence of TFL, resulting in the substitution of amino acid Gln to Glu at position 68 in the protein sequence. Subsequently, an InDel marker was developed to aid the marker-assisted selection of TFL. The TFL in the expression parents within the same period was analysed using quantitative real-time PCR; the TFL expression was significantly higher in short fruits than long fruits. Therefore, TFL can be a candidate gene for determining the fruit length in snake gourd. Collectively, these findings improve our understanding of the genetic components associated with fruit length in snake gourds, which could aid the development of enhanced breeding strategies for plant species.

The introgression of BjMYB113 from Brassica juncea leads to purple leaf trait in Brassica napus.

The purple leaves of Brassica napus are abundant in anthocyanins, which are renowned for their role in conferring distinct colors, stress tolerance, and health benefits, however the genetic basis of this trait in B. napus remains largely unelucidated. Herein, the purple leaf B. napus (PL) exhibited purple pigments in the upper epidermis and a substantial increase in anthocyanin accumulation, particularly of cyanidin, compared to green leaf B. napus (GL). The genetic control of the purple leaf trait was attributed to a semi-dominant gene, pl, which was mapped to the end of chromosome A03. However, sequencing of the fragments amplified by the markers linked to pl indicated that they were all mapped to chromosome B05 from B. juncea. Within this B05 chromosomal segment, the BjMYB113 gene-specific marker showed perfect co-segregation with the purple leaf trait in the F2 population, suggesting that the BjMYB113 introgression from B. juncea was the candidate gene for the purple leaf trait in B. napus. To further verify the function of candidate gene, CRISPR/Cas9 was performed to knock out the BjMYB113 gene in PL. The three myb113 mutants exhibited evident green leaf phenotype, absence of purple pigments in the adaxial epidermis, and a significantly reduced accumulation of anthocyanin compared to PL. Additionally, the genes involved in positive regulatory (TT8), late anthocyanin biosynthesis (DFR, ANS, UFGT), as well as transport genes (TT19) were significantly suppressed in the myb113 mutants, further confirming that BjMYB113 was response for the anthocyanin accumulation in purple leaf B. napus. This study contributes to an advanced understanding of the regulation mechanism of anthocyanin accumulation in B. napus.

Fine mapping and identification of two NtTOM2A homeologs responsible for tobacco mosaic virus replication in tobacco (Nicotiana tabacum L.).

BACKGROUND: Tobacco mosaic virus (TMV) is a widely distributed viral disease that threatens many vegetables and horticultural species. Using the resistance gene N which induces a hypersensitivity reaction, is a common strategy for controlling this disease in tobacco (Nicotiana tabacum L.). However, N gene-mediated resistance has its limitations, consequently, identifying resistance genes from resistant germplasms and developing resistant cultivars is an ideal strategy for controlling the damage caused by TMV. RESULTS: Here, we identified highly TMV-resistant tobacco germplasm, JT88, with markedly reduced viral accumulation following TMV infection. We mapped and cloned two tobamovirus multiplication protein 2A (TOM2A) homeologs responsible for TMV replication using an F2 population derived from a cross between the TMV-susceptible cultivar K326 and the TMV-resistant cultivar JT88. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated loss-of-function mutations of two NtTOM2A homeologs almost completely suppressed TMV replication; however, the single gene mutants showed symptoms similar to those of the wild type. Moreover, NtTOM2A natural mutations were rarely detected in 577 tobacco germplasms, and CRISPR/Cas9-mediated variation of NtTOM2A led to shortened plant height, these results indicating that the natural variations in NtTOM2A were rarely applied in tobacco breeding and the NtTOM2A maybe has an impact on growth and development. CONCLUSIONS: The two NtTOM2A homeologs are functionally redundant and negatively regulate TMV resistance. These results deepen our understanding of the molecular mechanisms underlying TMV resistance in tobacco and provide important information for the potential application of NtTOM2A in TMV resistance breeding.

Quick and affordable DNA cloning by reconstitution of Seamless Ligation Cloning Extract using defined factors.

The cloning of DNA fragments to plasmid vectors is at the heart of molecular biology. Recent developments have led to various methods utilizing homologous recombination of homology arms. Among them, Seamless Ligation Cloning Extract (SLiCE) is an affordable alternative solution that uses simple Escherichia coli lysates. However, the underlying molecular mechanisms remain unclear and the reconstitution of the extract by defined factors has not yet been reported. We herein show that the key factor in SLiCE is Exonuclease III (ExoIII), a double-strand (ds) DNA-dependent 3'-5' exonuclease, encoded by XthA. SLiCE prepared from the xthAΔ strain is devoid of recombination activity, whereas purified ExoIII alone is sufficient to assemble two blunt-ended dsDNA fragments with homology arms. In contrast to SLiCE, ExoIII is unable to digest (or assemble) fragments with 3' protruding ends; however, the addition of single-strand DNA-targeting Exonuclease T overcomes this issue. Through the combination of commercially available enzymes under optimized conditions, we achieved the efficient, reproducible, and affordable cocktail, "XE cocktail," for seamless DNA cloning. By reducing the cost and time required for DNA cloning, researchers will devote more resources to advanced studies and the careful validation of their own findings.

Natural variation of WBR7 confers rice high yield and quality by modulating sucrose supply in sink organs.

Grain chalkiness is an undesirable trait that negatively regulates grain yield and quality in rice. However, the regulatory mechanism underlying chalkiness is complex and remains unclear. We identified a positive regulator of white-belly rate (WBR). The WBR7 gene encodes sucrose synthase 3 (SUS3). A weak functional allele of WBR7 is beneficial in increasing grain yield and quality. During the domestication of indica rice, a functional G/A variation in the coding region of WBR7 resulted in an E541K amino acid substitution in the GT-4 glycosyltransferase domain, leading to a significant decrease in decomposition activity of WBR7A (allele in cultivar Jin23B) compared with WBR7G (allele in cultivar Beilu130). The NIL(J23B) and knockout line NIL(BL130)KO exhibited lower WBR7 decomposition activity than that of NIL(BL130) and NIL(J23B)COM, resulting in less sucrose decomposition and metabolism in the conducting organs. This caused more sucrose transportation to the endosperm, enhancing the synthesis of storage components in the endosperm and leading to decreased WBR. More sucrose was also transported to the anthers, providing sufficient substrate and energy supply for pollen maturation and germination, ultimately leading to an increase rate of seed setting and increased grain yield. Our findings elucidate a mechanism for enhancing rice yield and quality by modulating sucrose metabolism and allocation, and provides a valuable allele for improved rice quality.

Structural characterization of M8C10, a neutralizing antibody targeting a highly conserved prefusion-specific epitope on the metapneumovirus fusion trimerization interface.

IMPORTANCE: Human metapneumovirus (hMPV) is a common pathogen causing lower respiratory tract infections worldwide and can develop severe symptoms in high-risk populations such as infants, the elderly, and immunocompromised patients. There are no approved hMPV vaccines or neutralizing antibodies available for therapeutic or prophylactic use. The trimeric hMPV fusion F protein is the major target of neutralizing antibodies in human sera. Understanding the immune recognition of antibodies to hMPV-F antigen will provide critical insights into developing efficacious hMPV monoclonal antibodies and vaccines.

Combinatorial biosynthesis in yeast leads to over 200 diterpenoids.

Diterpenoids form a diverse group of natural products, many of which are or could become pharmaceuticals or industrial chemicals. The modular character of diterpene biosynthesis and the promiscuity of the enzymes involved make combinatorial biosynthesis a promising approach to generate libraries of diverse diterpenoids. Here, we report on the combinatorial assembly in yeast of ten diterpene synthases producing (+)-copalyl diphosphate-derived backbones and four cytochrome P450 oxygenases (CYPs) in diverse combinations. This resulted in the production of over 200 diterpenoids. Based on literature and chemical database searches, 162 of these compounds can be considered new-to-Nature. The CYPs accepted most substrates they were given but remained regioselective with few exceptions. Our results provide the basis for the systematic exploration of the diterpenoid chemical space in yeast using sequence databases.