Discovery and engineering of ChCas12b for precise genome editing.

Many clustered regularly interspaced short palindromic repeat and CRISPR-associated protein 12b (CRISPR-Cas12b) nucleases have been computationally identified, yet their potential for genome editing remains largely unexplored. In this study, we conducted a GFP-activation assay screening 13 Cas12b nucleases for mammalian genome editing, identifying five active candidates. Candidatus hydrogenedentes Cas12b (ChCas12b) was found to recognize a straightforward WTN (W = T or A) proto-spacer adjacent motif (PAM), thereby dramatically expanding the targeting scope. Upon optimization of the single guide RNA (sgRNA) scaffold, ChCas12b exhibited activity comparable to SpCas9 across a panel of nine endogenous loci. Additionally, we identified nine mutations enhancing ChCas12b specificity. More importantly, we demonstrated that both ChCas12b and its high-fidelity variant, ChCas12b-D496A, enabled allele-specific disruption of genes harboring single nucleotide polymorphisms (SNPs). These data position ChCas12b and its high-fidelity counterparts as promising tools for both fundamental research and therapeutic applications.

Lyophilizable Stem Cell-Hybrid Liposome with Long-Term Stability and High Targeting Capacity.

The hybridization of liposome with stem cell membranes is an emerging technology to prepare the nanovehicle with the capacity of disease-responsive targeting. However, the long-term storage of this hybrid liposome has received limited attention in the literature, which is essential for its potential applicability in the clinic. Therefore, the preservation of long-term activity of stem cell-hybrid liposome using freeze-drying is investigated in the present study. Mesenchymal stem cell-hybrid liposome is synthesized and its feasibility for freeze-drying under different conditions is examined. Results reveal that pre-freezing the hybrid liposome at -20 °C in Tris buffer solution (pH 7.4) containing 10% trehalose can well preserve the liposomal structure for at least three months. Notably, major membrane proteins on the hybrid liposome are protected in this formulation and CXCR4-associated targeting capacity is maintained both in vitro and in vivo. Consequently, the hybrid liposome stored for three months demonstrates a comparable tumor inhibition as the fresh-prepared one. The present study provides the first insights into the long-term storage of stem cell hybrid liposome using lyophilization, which may make an important step forward in enhancing the long-term stability of these promising biomimetic nanovehicle and ease the logistics and the freeze-storage in the potential clinical applications.

The 3-Dimensional Intelligent Structured Light Technique: A New Registration Method in Stereotactic Neurosurgery.

BACKGROUND AND OBJECTIVES: Surface-based facial scanning registration emerged as an essential registration method in the robot-assisted neuronavigation surgery, providing a marker-free way to align a patient's facial surface with the imaging data. The 3-dimensional (3D) structured light was developed as an advanced registration method based on surface-based facial scanning registration. We aspire to introduce the 3D structured light as a new registration method in the procedure of the robot-assisted neurosurgery and assess the accuracy, efficiency, and safety of this method by analyzing the relative operative results. METHODS: We analyzed the results of 47 patients who underwent Ommaya reservoir implantation (n = 17) and stereotactic biopsy (n = 30) assisted by 3D structured light at our hospital from January 2022 to May 2023. The accuracy and additional operative results were analyzed. RESULTS: For the Ommaya reservoir implantation, the target point error was 3.2 ± 2.2 mm and the entry point error was 3.3 ± 2.4 mm, while the operation duration was 35.8 ± 8.3 minutes. For the stereotactic biopsy, the target point error was 2.3 ± 1.3 mm and the entry point error was 2.7 ± 1.2 mm, while the operation duration was 24.5 ± 6.3 minutes. CONCLUSION: The 3D structured light technique reduces the patients' discomfort and offers the advantage of a simpler procedure, which can improve the clinical efficiency with the sufficient accuracy and safety to meet the clinical requirements of the puncture and navigation.

Efficient intervention for pulmonary fibrosis via mitochondrial transfer promoted by mitochondrial biogenesis.

The use of exogenous mitochondria to replenish damaged mitochondria has been proposed as a strategy for the treatment of pulmonary fibrosis. However, the success of this strategy is partially restricted by the difficulty of supplying sufficient mitochondria to diseased cells. Herein, we report the generation of high-powered mesenchymal stem cells with promoted mitochondrial biogenesis and facilitated mitochondrial transfer to injured lung cells by the sequential treatment of pioglitazone and iron oxide nanoparticles. This highly efficient mitochondrial transfer is shown to not only restore mitochondrial homeostasis but also reactivate inhibited mitophagy, consequently recovering impaired cellular functions. We perform studies in mouse to show that these high-powered mesenchymal stem cells successfully mitigate fibrotic progression in a progressive fibrosis model, which was further verified in a humanized multicellular lung spheroid model. The present findings provide a potential strategy to overcome the current limitations in mitochondrial replenishment therapy, thereby promoting therapeutic applications for fibrotic intervention.

The prognostic value of cancer stage-associated genes in clear cell renal cell carcinoma.

OBJECTIVES: Clear cell renal cell carcinoma (ccRCC) is a highly prevalent subtype of malignant renal tumor, but unfortunately, the survival rate remains unsatisfactory. The aim of the present study is to explore genomic features that are correlated with cancer stage, allowing for the identification of subgroups of ccRCC patients with high risk of unfavorable outcomes and enabling prompt intervention and treatment. METHODS: We compared the gene expression levels across ccRCC patients with diverse cancer stages from The Cancer Genome Atlas (TCGA) database, which revealed characteristic genes associated with tumor stage. We then extracted prognostic genes and used least absolute shrinkage selection operator (LASSO) regression to select four genes for feature extraction and the construction of a prognostic risk model. RESULTS: We have identified a total of 171 differentially expressed genes (DEGs) that are closely linked to the tumor stage of ccRCC through difference analysis. A prognostic risk model constructed based on the expression levels of ZIC2, TFAP2A-AS1, ITPKA, and SLC16A12 holds significant prognostic value in ccRCC. The results of the functional enrichment analysis imply that the DEGs are mainly involved in the regulation of immune-related signaling pathways, and therefore may have a significant function in immune system regulation of ccRCC. CONCLUSIONS: Our study has successfully identified significant DEGs between high- and low-staging groups of ccRCC using bioinformatics methods. The construction of a prognostic risk model based on the expression levels of ZIC2, TFAP2A-AS1, ITPKA, and SLC16A12 has displayed promising prognostic significance, indicating its valuable potential for clinical application.

FBN1 knockout promotes cervical artery dissection by inducing N-glycosylation alternation of extracellular matrix proteins in rat VSMCs.

FBN1 mutation promotes the degeneration of microfibril structures and extracellular matrix (ECM) integrity in the tunica media of the aorta in Marfan syndrome. However, whether FBN1 modulates cervical artery dissection (CAD) development and the potential molecular mechanisms of abnormal FBN1 in CAD remains elusive. In this study, FBN1 deficiency participated in the development of CAD and influenced the proliferation, apoptosis, and migration of vascular smooth muscle cells. FBN1 knockout induced alternations in mRNA levels of the transcriptome, protein expression of the proteome, and abundance of N-glycosylation of the N-glycoproteome. Comprehensive analysis of multiple omics showed up-regulation in mRNA levels of ECM proteins; yet, both the ECM protein levels and relative abundance of N-glycosylation were decreased. Moreover, we performed in vivo experiments to confirm the altered glycosylation of proteins in vascular smooth muscle cells. In conclusion, FBN1 deletion in vascular smooth muscle cells can result in altered N-glycosylation of ECM protein, which were critical for the stability of ECM and the process of CAD. This may open the way for a novel therapeutic strategy to treat people with CAD.

Thyroid transcription factor 1 (TTF-1) negativity as a predictor of unfavorable response to EGFR-TKI therapy in advanced lung adenocarcinoma patients with EGFR mutations.

BACKGROUND: The absence of thyroid transcription factor 1 (TTF-1) is associated with a lower frequency of epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma (LUAD). The aim of this study was to assess the impact of TTF-1 expression on the clinical response to EGFR-tyrosine kinase inhibitor (TKI) treatment in patients with advanced LUAD. METHODS: The data of patients with advanced LUAD who were admitted to the Beijing Tiantan Hospital and Peking University Cancer Hospital (China) between April 2009 and May 2023 was retrospectively analyzed. RESULTS: A total of 227 patients diagnosed with advanced LUAD were included, of which 28.2% (64/227) had TTF-1-negative adenocarcinoma, while 54.6% (124/227) harbored EGFR mutations. Negative TTF-1 expression significantly correlated with male sex (68.8% vs. 42.3%, p < 0.001), history of heavy smoking (57.8% vs. 36.2%, p = 0.003), poorly differentiated tumors (86.5% vs. 43.2%, p < 0.001), and lower frequency of EGFR mutations (26.6% vs. 65.6%, p < 0.001) compared with TTF-1 positivity. Multivariable logistic regression showed that low prevalence of EGFR mutations (p < 0.001) and male sex (p = 0.006) were independent predictive factors for the negative expression of TTF-1. Patients lacking TTF-1 also exhibited worse overall response rate (ORR; 23.5% vs. 54.2%, p = 0.019), disease control rate (DCR; 58.8% vs. 89.7%, p = 0.003), and median progression-free survival (PFS; 2.9 vs. 11.6 months, p < 0.001) following treatment with EGFR-TKIs compared to the TTF-1-positive patients with EGFR mutations. CONCLUSIONS: Patients with TTF-1-negative and EGFR-mutant LUAD show a diminished response to EGFR-TKIs.

High Targeting Specificity toward Pulmonary Inflammation Using Mesenchymal Stem Cell-Hybrid Nanovehicle for an Efficient Inflammation Intervention.

Pulmonary inflammation is one of the most reported tissue inflammations in clinic. Successful suppression of inflammation is vital to prevent further inevitably fatal lung degeneration. Glucocorticoid hormone, such as methylprednisolone (MP), is the most applied strategy to control the inflammatory progression yet faces the challenge of systemic side effects caused by the requirement of large-dosage and frequent administration. Highly efficient delivery of MP specifically targeted to inflammatory lung sites may overcome this challenge. Therefore, the present study develops an inflammation-targeted biomimetic nanovehicle, which hybridizes the cell membrane of mesenchymal stem cell with liposome, named as MSCsome. This hybrid nanovehicle shows the ability of high targeting specificity toward inflamed lung cells, due to both the good lung endothelium penetration and the high uptake by inflamed lung cells. Consequently, a single-dose administration of this MP-loaded hybrid nanovehicle achieves a prominent treatment of lipopolysaccharide-induced lung inflammation, and negligible treatment-induced side effects are observed. The present study provides a powerful inflammation-targeted nanovehicle using biomimetic strategy to solve the current challenges of targeted inflammation intervention.

The Regulatory Axis of PD-L1 Isoform 2/TNF/T Cell Proliferation Is Required for the Canonical Immune-Suppressive Effects of PD-L1 Isoform 1 in Liver Cancer.

Despite the well-studied effects of the full-length membrane-locating isoform Iso1 of Programmed Cell Death Protein-Ligand 1 (PD-L1) on immunosuppression, little is known about another membrane-locating isoform, Iso2. While expressional and survival analysis of liver cancer patients indicated that Iso2 plays a tumor-suppressive role, our results also indicated that the tumor-promoting and immune-suppressive effects of Iso1 depended on the positive expression of Iso2. Through mediation analysis, we discovered several downstream genes or pathways of Iso2 and investigated their effects on the Iso1-regulating survival. Among all potential downstream immune factors, Iso2 was inclined to activate the proliferation of T cells by regulating chemokine activity and increasing CD3 levels by promoting TNF expression. Similar results were confirmed in the Mongolian liver cancer cohort, and the Iso2/TNF/T-cell axis was verified in several other cancers in the TCGA cohort. Finally, we demonstrated the promoting effects of Iso2 in terms of producing TNF and increasing T cells both in vitro and in vivo. Our findings illustrate that PD-L1 Iso2 can increase the number of T cells in the tumor microenvironment by elevating TNF levels, which is a necessary part of the tumor-suppressive effects of Iso1 in liver cancer.

Cell-derived membrane biomimetic nanocarriers for targeted therapy of pulmonary disease.

Pulmonary diseases are currently one of the major threats of human health, especially considering the recent COVID-19 pandemic. However, the current treatments are facing the challenges like insufficient local drug concentrations, the fast lung clearance and risks to induce unexpected inflammation. Cell-derived membrane biomimetic nanocarriers are recently emerged delivery strategy, showing advantages of long circulation time, excellent biocompatibility and immune escape ability. In this review, applications of using cell-derived membrane biomimetic nanocarriers from diverse cell sources for the targeted therapy of pulmonary disease were summarized. In addition, improvements of the cell-derived membrane biomimetic nanocarriers for augmented therapeutic ability against different kinds of pulmonary diseases were introduced. This review is expected to provide a general guideline for the potential applications of cell-derived membrane biomimetic nanocarriers to treat pulmonary diseases.

A Novel circRNA-miRNA-mRNA Hub Regulatory Network in Lung Adenocarcinoma.

The growing evidence suggests that circular RNAs (circRNAs) have significant associations with tumor occurrence and progression, yet the regulatory mechanism of circRNAs in lung adenocarcinoma (LUAD) remains unclear. This study clarified the potentially regulatory network and functional mechanism of circRNAs in LUAD. The expression data of circRNAs, microRNAs (miRNAs), and messenger RNAs (mRNAs) were obtained from the Gene Expression Omnibus (GEO) database. Relying on GSE101586, GSE101684, and GSE112214, we identified differentially expressed circRNAs (DEcircRNAs). Depending on GSE135918 and GSE32863, we screened out differentially expressed miRNAs (DEmiRNAs) and mRNAs (DEmRNAs), respectively. Then, a novel competing endogenous RNA (ceRNA) regulatory network related to LUAD was constructed. We also revealed biological processes and signal pathways regulated by these DEcircRNAs. Based on gene expression data and survival information of LUAD patients in The Cancer Genome Atlas (TCGA) and GEO, we implemented survival analysis to select DEmRNAs related to prognosis and build a novel circRNA-miRNA-mRNA hub regulatory network. Meanwhile, quantitative real-time PCR (qRT-PCR) was utilized to validate DEcircRNAs in the ceRNA hub regulatory network. As a result, a total of 8 DEcircRNAs, 19 DEmiRNAs, and 85 DEmRNAs were identified. The novel ceRNA regulatory network included 5 circRNAs, 8 miRNAs, and 22 mRNAs. The final ceRNA hub regulatory network contained two circRNAs, two miRNAs, and two mRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that the five DEcircRNAs may affect LUAD onset and progression through Wnt signaling pathway and Hippo signaling pathway. All in all, this study revealed the regulatory network and functional mechanism of circRNA-related ceRNAs in LUAD.

Intestinal gangrene secondary to congenital transmesenteric hernia in a child misdiagnosed with gastrointestinal bleeding: A case report.

BACKGROUND: Congenital transmesenteric hernia in children is a rare and potentially fatal form of internal abdominal hernia, and no specific clinical symptoms can be observed preoperatively. Therefore, this condition is not widely known among clinicians, and it is easily misdiagnosed, resulting in disastrous effects. CASE SUMMARY: This report presents the case of a 13-year-old boy with a chief complaint of abdominal pain and vomiting and a history of duodenal ulcer. The patient was misdiagnosed with gastrointestinal bleeding and treated conservatively at first. Then, the patient's symptoms were aggravated and he presented in a shock-like state. Computed tomography revealed a suspected internal hernia, extensive small intestinal obstruction, and massive effusion in the abdominal and pelvic cavity. Intraoperative exploration found a small mesenteric defect approximately 3.5 cm in diameter near the ileocecal valve, and there was about 1.8 m of herniated small intestine that was treated by resection and anastomosis. The patient recovered well and was followed for more than 5 years without developing short bowel syndrome. CONCLUSION: In this report, we review the pathogenesis, presentation, diagnosis, and treatment of congenital transmesenteric hernia in children.

Xa7, a new executor R gene that confers durable and broad-spectrum resistance to bacterial blight disease in rice.

Bacterial blight (BB) is a globally devastating rice disease caused by Xanthomonas oryzae pv. oryzae (Xoo). The use of disease resistance (R) genes in rice breeding is an effective and economical strategy for the control of this disease. Nevertheless, a majority of R genes lack durable resistance for long-term use under global warming conditions. Here, we report the isolation of a novel executor R gene, Xa7, that confers extremely durable, broad-spectrum, and heat-tolerant resistance to Xoo. The expression of Xa7 was induced by incompatible Xoo strains that secreted the transcription activator-like effector (TALE) AvrXa7 or PthXo3, which recognized effector binding elements (EBEs) in the Xa7 promoter. Furthermore, Xa7 induction was faster and stronger under high temperatures. Overexpression of Xa7 or co-transformation of Xa7 with avrXa7 triggered a hypersensitive response in plants. Constitutive expression of Xa7 activated a defense response in the absence of Xoo but inhibited the growth of transgenic rice plants. In addition, analysis of over 3000 rice varieties showed that the Xa7 locus was found primarily in the indica and aus subgroups. A variation consisting of an 11-bp insertion and a base substitution (G to T) was found in EBEAvrXa7 in the tested varieties, resulting in a loss of Xa7 BB resistance. Through a decade of effort, we have identified an important BB resistance gene and characterized its distinctive interaction with Xoo strains; these findings will greatly facilitate research on the molecular mechanism of Xa7-mediated resistance and promote the use of this valuable gene in breeding.

The B3 domain-containing transcription factor ZmABI19 coordinates expression of key factors required for maize seed development and grain filling.

Grain filling in maize (Zea mays) is regulated by a group of spatiotemporally synchronized transcription factors (TFs), but the factors that coordinate their expression remain unknown. We used the promoter of the grain filling-specific TF gene Opaque2 (O2) to screen upstream regulatory factors and identified a B3 domain TF, ZmABI19, that directly binds to the O2 promoter for transactivation. zmabi19 mutants displayed developmental defects in the endosperm and embryo, and mature kernels were opaque and reduced in size. The accumulation of zeins, starch and lipids dramatically decreased in zmabi19 mutants. RNA sequencing revealed an alteration of the nutrient reservoir activity and starch and sucrose metabolism in zmabi19 endosperms, and plant phytohormone signal transduction and lipid metabolism in zmabi19 embryos. Chromatin immunoprecipitation followed by sequencing coupled with differential expression analysis identified 106 high-confidence direct ZmABI19 targets. ZmABI19 directly regulates multiple key grain filling TFs including O2, Prolamine-box binding factor 1, ZmbZIP22, NAC130, and Opaque11 in the endosperm and Viviparous1 in the embryo. A number of phytohormone-related genes were also bound and regulated by ZmABI19. Our results demonstrate that ZmABI19 functions as a grain filling initiation regulator. ZmABI19 roles in coupling early endosperm and embryo development are also discussed.

Angiogenesis is promoted by exosomal DPP4 derived from 5-fluorouracil-resistant colon cancer cells.

Cancer cells can communicate with the tumor microenvironment and contribute to tumor progression. However, the effects of drug-resistant tumor cells on angiogenesis are unclear. Current anti-angiogenic strategies also have limitations and it would be useful to develop novel targets and treatment strategies. Here, our study showed that the conditioned medium and exosomes from 5-FU-resistant colon cancer cells promoted angiogenesis, and we observed that exosomal dipeptidyl peptidase IV (DPP4) was a potent inducer of this angiogenesis. DPP4-enriched exosomes increased periostin (POSTN) expression in human umbilical vein endothelial cells via Twist1 nuclear translocation or activating Smad signaling pathway, while silencing or inhibition of DPP4 neutralized those effects. The in vivo and clinical data indicated that high DPP4 expression was related to tumor progression. These findings indicate that DPP4 may be a target for inhibiting angiogenesis in 5-FU-resistant colon cancer. Furthermore, exosomal DPP4 concentrations may be a useful prognostic marker for colon cancer.

Exosomes derived from 5-fluorouracil-resistant colon cancer cells are enriched in GDF15 and can promote angiogenesis.

Background: Angiogenesis is important for tumor proliferation and distant metastasis. However, the role of drug-resistant tumor cells in angiogenesis remains largely unknown. Current anti-angiogenic strategies also have limitations and it would be useful to develop novel targets and treatment strategies. Methods: Differential ultracentrifugation was used to isolate conditioned medium-derived exosomes from 5-flurouracil (5-FU)-sensitive or -resistant colon cancer cells. Exosome endocytosis into human umbilical vein endothelial cells was observed via immunofluorescence. Differentially expressed proteins in the exosomes were confirmed via qRT-PCR and Western blotting. The angiogenic capacity of endothelial cells was evaluated using cell function assays and a rat model of abdominal aortic neovascularization. The underlying mechanisms were verified using qRT-PCR and Western blotting assays. Immunohistochemistry was used to evaluate in vivo angiogenesis. Results: We observed that the conditioned medium and exosomes from 5-FU-resistant colon cancer cells could promote angiogenesis. Exosomal growth/differentiation factor 15 (GDF15) was a potent inducer of this angiogenesis in vitro by inhibiting the Smad signaling pathway, thus increasing periostin (POSTN) levels. Moreover, 5-FU-resistant colon cancer cells showed high microvascular density in vivo. TGF-ß1, an activator of the Smad signaling pathway, could partly eliminate those effects. Conclusions: Our study reveals the molecular regulation of angiogenesis in 5-FU-resistant colon cancer and suggests that the GDF15-POSTN axis may be a novel target for anti-angiogenic therapies in colon cancer.

GDF15 Repression Contributes to 5-Fluorouracil Resistance in Human Colon Cancer by Regulating Epithelial-Mesenchymal Transition and Apoptosis.

Chemotherapy based on 5-fluorouracil (5-FU) is the standard approach for colon cancer treatment, and resistance to 5-FU is a significant obstacle in the clinical treatment of colon cancer. However, the mechanisms underlying 5-FU resistance in colon cancer cells remain largely unknown. This study aimed at determining whether 5-FU-resistant colon cancer cells undergo epithelial-mesenchymal transition (EMT) and apoptosis and the role of GDF15-a member of the transforming growth factor ß/bone morphogenetic protein super family and a protein known to be involved in cancer progression-in the regulation of EMT and apoptosis of these cells, along with the underlying mechanisms. In vitro apoptosis detection assay, growth inhibition assay, transwell, and wound healing experiments revealed that 5-FU-resistant colon cancer cells possessed enhanced EMT and antiapoptotic ability. These cells also showed a stronger tendency to proliferate and metastasize in vivo. Quantitative reverse transcription-PCR and western blotting revealed that 5-FU-resistant colon cancer cells expressed lower levels of growth differentiation factor 15 (GDF15) than did 5-FU-sensitive colon cancer cells. Moreover, the transient GDF15 overexpression resensitized 5-FU-resistant colon cells to 5-FU. Collectively, these findings indicate the mechanism underlying the 5-FU resistance of colon cancer cells and provide new therapeutic targets for improving the prognosis of colon cancer patients.

A Randomized Controlled Trial of an Integrated Brain, Body, and Social Intervention for Children With ADHD.

Objective: This study evaluated the efficacy of an Integrated Brain, Body, and Social (IBBS) intervention for children with ADHD. Treatment consisted of computerized cognitive remediation training, physical exercises, and a behavior management strategy. Method: Ninety-two children aged 5 to 9 years with ADHD were randomly assigned to 15 weeks of IBBS or to treatment-as-usual. Primary outcome measures included blinded clinician ratings of ADHD symptoms and global clinical functioning. Secondary outcome measures consisted of parent and teacher ratings of ADHD and neurocognitive tests. Results: No significant treatment effects were found on any of our primary outcome measures. In terms of secondary outcome measures, the IBBS group showed significant improvement on a verbal working memory task; however, this result did not survive correction for multiple group comparisons. Conclusion: These results suggest that expanding cognitive training to multiple domains by means of two training modalities does not lead to generalized improvement of ADHD symptomatology.

Intra-Kernel Reallocation of Proteins in Maize Depends on VP1-Mediated Scutellum Development and Nutrient Assimilation.

During maize (Zea mays) seed development, the endosperm functions as the major organ for storage of photoassimilate, serving to nourish the embryo. α-Zeins and globulins (GLBs) predominantly accumulate in the maize endosperm and embryo, respectively. Here, we show that suppression of α-zeins by RNA interference (αRNAi) in the endosperm results in more GLB1 being synthesized in the embryo, thereby markedly increasing the size and number of protein storage vacuoles. Glb genes are strongly expressed in the middle-to-upper section of the scutellum, cells of which are significantly enlarged by αRNAi induction. Elimination of GLBs caused an apparent reduction in embryo protein level, regardless of whether α-zeins were expressed or suppressed in the endosperm, indicating that GLBs represent the dominant capacity for storage of amino acids allocated from the endosperm. It appears that protein reallocation is mostly regulated at the transcriptional level. Genes differentially expressed between wild-type and αRNAi kernels are mainly involved in sulfur assimilation and nutrient metabolism, and many are transactivated by VIVIPAROUS1 (VP1). In vp1 embryos, misshapen scutellum cells contain notably less cellular content and are unable to respond to αRNAi induction. Our results demonstrate that VP1 is essential for scutellum development and protein reallocation from the endosperm to embryo.