Functional characterization of D-type cyclins involved in cell division in rice.

BACKGROUND: D-type cyclins (CYCD) regulate the cell cycle G1/S transition and are thus closely involved in cell cycle progression. However, little is known about their functions in rice. RESULTS: We identified 14 CYCD genes in the rice genome and confirmed the presence of characteristic cyclin domains in each. The expression of the OsCYCD genes in different tissues was investigated. Most OsCYCD genes were expressed at least in one of the analyzed tissues, with varying degrees of expression. Ten OsCYCD proteins could interact with both retinoblastoma-related protein (RBR) and A-type cyclin-dependent kinases (CDKA) forming holistic complexes, while OsCYCD3;1, OsCYCD6;1, and OsCYCD7;1 bound only one component, and OsCYCD4;2 bound to neither protein. Interestingly, all OsCYCD genes except OsCYCD7;1, were able to induce tobacco pavement cells to re-enter mitosis with different efficiencies. Transgenic rice plants overexpressing OsCYCD2;2, OsCYCD6;1, and OsCYCD7;1 (which induced cell division in tobacco with high-, low-, and zero-efficiency, respectively) were created. Higher levels of cell division were observed in both the stomatal lineage and epidermal cells of the OsCYCD2;2- and OsCYCD6;1-overexpressing plants, with lower levels seen in OsCYCD7;1-overexpressing plants. CONCLUSIONS: The distinct expression patterns and varying effects on the cell cycle suggest different functions for the various OsCYCD proteins. Our findings will enhance understanding of the CYCD family in rice and provide a preliminary foundation for the future functional verification of these genes.

Cholelithiasis and cholecystectomy increase the risk of gastroesophageal reflux disease and Barrett's esophagus.

Background: Cholelithiasis or cholecystectomy may contribute to the development of gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and esophageal adenocarcinoma (EAC) through bile reflux; however, current observational studies yield inconsistent findings. We utilized a novel approach combining meta-analysis and Mendelian randomization (MR) analysis, to assess the association between them. Methods: The literature search was done using PubMed, Web of Science, and Embase databases, up to 3 November 2023. A meta-analysis of observational studies assessing the correlations between cholelithiasis or cholecystectomy, and the risk factors for GERD, BE, and EACwas conducted. In addition, the MR analysis was employed to assess the causative impact of genetic pre-disposition for cholelithiasis or cholecystectomy on these esophageal diseases. Results: The results of the meta-analysis indicated that cholelithiasis was significantly linked to an elevated risk in the incidence of BE (RR, 1.77; 95% CI, 1.37-2.29; p < 0.001) and cholecystectomy was a risk factor for GERD (RR, 1.37; 95%CI, 1.09-1.72; p = 0.008). We observed significant genetic associations between cholelithiasis and both GERD (OR, 1.06; 95% CI, 1.02-1.10; p < 0.001) and BE (OR, 1.21; 95% CI, 1.11-1.32; p < 0.001), and a correlation between cholecystectomy and both GERD (OR, 1.04; 95% CI, 1.02-1.06; p < 0.001) and BE (OR, 1.13; 95% CI, 1.06-1.19; p < 0.001). After adjusting for common risk factors, such as smoking, alcohol consumption, and BMI in multivariate analysis, the risk of GERD and BE still persisted. Conclusion: Our study revealed that both cholelithiasis and cholecystectomy elevate the risk of GERD and BE. However, there is no observed increase in the risk of EAC, despite GERD and BE being the primary pathophysiological pathways leading to EAC. Therefore, patients with cholelithiasis and cholecystectomy should be vigilant regarding esophageal symptoms; however, invasive EAC cytology may not be necessary.

YGL3 Encoding an IPP and DMAPP Synthase Interacts with OsPIL11 to Regulate Chloroplast Development in Rice.

As the source of isoprenoid precursors, the plastidial methylerythritol phosphate (MEP) pathway plays an essential role in plant development. Here, we report a novel rice (Oryza sativa L.) mutant ygl3 (yellow-green leaf3) that exhibits yellow-green leaves and lower photosynthetic efficiency compared to the wild type due to abnormal chloroplast ultrastructure and reduced chlorophyll content. Map-based cloning showed that YGL3, one of the major genes involved in the MEP pathway, encodes 4-hydroxy-3-methylbut-2-enyl diphosphate reductase, which is localized in the thylakoid membrane. A single base substitution in ygl3 plants resulted in lower 4-hydroxy-3-methylbut-2-enyl diphosphate reductase activity and lower contents of isopentenyl diphosphate (IPP) compared to the wild type. The transcript levels of genes involved in the syntheses of chlorophyll and thylakoid membrane proteins were significantly reduced in the ygl3 mutant compared to the wild type. The phytochrome interacting factor-like gene OsPIL11 regulated chlorophyll synthesis during the de-etiolation process by directly binding to the promoter of YGL3 to activate its expression. The findings provides a theoretical basis for understanding the molecular mechanisms by which the MEP pathway regulate chloroplast development in rice.