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Biomedical subjects

Jing Cai

Publications and source records attributed to Jing Cai.

3 recordsLinked to original sources

Human m6A demethylase FTO modulates the flowering time of tomato plants under low-temperature stress.

N6-methyladenosine (m6A) RNA modification plays an important role in plant development and environmental stress responses. However, whether m6A demethylation modulates flowering under low-temperature (LT) stress in tomatoes remains unclear. Here, we investigated whether ectopic expression of FTO, a well-characterized human m6A demethylase, influences flowering and post-transcriptional behaviour in tomato (Solanum lycopersicum) under LT conditions. Flowering of transgenic tomato plants expressing FTO was analyzed under LT and normal conditions (NC), and the impacts of FTO on transcripts-specific m6A level, mRNA stability and splicing efficiency of flowering-related genes were evaluated using RT-qPCR, LC-MS/MS, m6A-IP-qPCR, and RNA decay and splicing analyses. FTO-expressing plants exhibited accelerated flowering specifically under LT, whereas no significant differences were observed under normal growth conditions. This phenotype was accompanied by increased expression of positive floral regulators (SlMC, SlFCA, and SlJ2) and decreased expression of negative regulators (SlSVP, SlSP, and SlTMF) under LT conditions. Notably, these expression changes were associated with altered mRNA stability, with positive regulators showing increased stability and negative regulators showing reduced stability under LT conditions. m6A-IP-qPCR analysis indicated reduced m6A enrichment in these selected transcripts in FTO-expressing plants. In addition to effects on mRNA stability, FTO expression was associated with changes in the splicing efficiency of SlMC transcripts. Collectively, our findings indicate that human FTO functions as an mRNA m6A demethylase in tomatoes and is associated with altered RNA regulatory processes under LT conditions. These findings suggest that m6A-mediated post-transcriptional regulation contributes to stress-induced flowering plasticity under LT conditions, rather than direct activation of canonical flowering pathways.

Abiotic stress

A chromosome-level genome assembly of Lycoris radiata reveals the evolutionary origin of Amaryllidaceae alkaloids and elucidates the complete galanthamine biosynthetic pathway.

Amaryllidaceae alkaloids (AmAs) comprise a structurally diverse group of specialized metabolites produced almost exclusively by species of the Amaryllidoideae subfamily and are of substantial pharmacological importance. However, the limited availability of high-quality genomes from Amaryllidoideae plants has constrained systematic investigations of the genes and evolutionary processes underlying AmA biosynthesis. Here, we present a chromosome-level genome assembly of Lycoris radiata, which enabled the discovery of key downstream enzymes in the galanthamine biosynthetic pathway and uncovered reversible reactions between two critical metabolite pairs. These findings provide new mechanistic insight into pathway architecture and enable reconstruction of the galanthamine biosynthetic pathway in Yarrowia lipolytica. Comparative genomic analyses indicate that several core genes for AmA biosynthesis originated in ancestral angiosperms, whereas the complete pathway was likely assembled in the Amaryllidoideae subfamily through gene duplication and neofunctionalization. Furthermore, integrated metabolomic and transcriptomic analyses suggest that roots contribute actively to AmA metabolism in Lycoris. Together, these findings provide a genomic and biochemical framework for understanding the evolution and engineering of AmA biosynthesis.

Lycoris

Pupil dynamics in macaque recognition memory tasks: investigating physiological mechanisms.

Cognitive deficits are common in primates, particularly in memory and emotional processes. Rhesus monkey (Macaca mulatta), widely used in cognitive and behavioral research, are central to memory studies. The relationship between recognition memory performance and pupillary dynamics in rhesus monkeys remains underexplored. This study investigated pupil dynamics during recognition memory tasks and their physiological correlates in five sexually mature male rhesus monkeys. We measured pupil diameter and oscillatory features during tasks and analyzed the relationship between behavioral performance and physiological indicators. We found that the average correct response rate exceeded the random success level, and reaction times were significantly shorter during successful recognition than failures, highlighting their cognitive efficiency. During recognition of familiar scenes, average pupil diameter increased, while maximum change in pupil size decreased, indicating reduced cognitive load. Both the frequency and amplitude of pupillary oscillation were lower during successful trials, reflecting decreased cognitive conflict and effective processing. This change reflects a decrease in cognitive conflict and suggests that information processing was more effective. The absolute value of the pupil peak slope decreased during successful recognition, indicating more stable cognitive state. These results support that pupillary dynamics can serve as physiological markers of cognitive effort in rhesus monkeys. Future studies should investigate how stimulus characteristics influence recognition and incorporate measures, such as intracranial EEG and fMRI, to enhance our understanding of their neural mechanisms. This research supports the rhesus monkey model in cognitive neuroscience and contributes to understanding primate cognition and its physiological foundations, with implications for clinical and translational research.

Animals