Biomedical subjects

Yi Guo

Publications and source records attributed to Yi Guo.

2 recordsLinked to original sources

PubMed2026

A newly established reverse genetic system for a circular RNA virus reveals new requirements for infection and its biocontrol potential.

Ambiviruses are fungal-infecting circular RNA viruses that uniquely combine viroid-like and viral features, yet the function of their conserved ORF-B protein and their effects on hosts remain unknown, hindered by the lack of a reverse genetics system. Here, we constructed the first infectious cDNA clone of an ambivirus, Fusarium graminearum ambivirus 1 (FgAV1), using a head-to-tail dimer placed downstream of a fungal promoter. FgAV1 was horizontally transmitted via hyphal anastomosis to virus-free Fusarium graminearum strains. Notably, a reverse-oriented dimer construct was also infectious and transmissible. Targeted mutagenesis revealed that both ORF-A- and ORF-B-encoded proteins and the presence of embedded ribozymes are indispensable for ambivirus replication. Our results further demonstrate that FgAV1 infection triggers a fungal RNAi response, extending the antiviral role of host sRNAs to circular RNA viruses. Furthermore, FgAV1 infection suppressed fungal growth and significantly reduced the virulence of F. graminearum on wheat. These findings provide novel insights into ambivirus replication and their potential in fungal pathogen biocontrol.

RNA Viruses↗

PubMed2025

Architectural transcription factors collectively shape nuclear radial positioning of chromatin contacts.

The measurement of three-dimensional genome folding in the nucleus, mostly through Hi-C methods, is expressed as contact frequencies between genomic segments, without anchoring to physical axes of the spherical nucleus. Here, we mapped the chromatin contacts along nuclear radial axis and built radial score by factoring in contact frequencies. The chromatin high-order structures exhibit rich diversity along radial axis. Furthermore, the proximal trans contacts retrieved by radial score reveal conserved active/inactive chromatin segregation across intra- and interchromosomal interactions. Ablation of CTCF proteins disrupts chromatin loops with mild changes to chromatin radial positioning. By acutely perturbing multiple transcription factor (TF) occupancy, chromatin loop dissolutions are often accompanied by radial dissociations between two anchors. Our work provides a genome architecture reference map adhering to nuclear physical axis and suggests that multiple architectural TFs collectively shape nuclear positioning of chromatin and their contacts, with contacts serving as forces on chromatin positioning as well.

Chromatin↗