b'UK Associate professor Tomo Kawashima (right) studies Arabidopsis with graduate students Vijyesh Sharma (middle) and Ashwini Shivakumar (left).He says this tag normally directs proteins to specific cellWe still rely on transgene expression to understand the compartments. Proteins with the tag glow under a microscope,function or gene regulations, he says. Its still difficult for us indicating production and localization within the cell. However,to monitor all these endogenous genes because we cannot proteins without this tag, which should be floating freely insidedistinguish well. But if we can have the transgene fused with this the cell, show no signals.fluorescent protein then we can let them glow whenever theyre We found that either RNAs for these tag-less proteinsactive. When they glow, it means proteins are generated and are not generated or they are rapidly degraded, leading toshow this localization inside the cell.no detectable RNA, Kawashima explains. This discoveryThe big question now is, what causes GESENI? It seems to is a novel gene silencing phenomenon specific to spermbe selective, targeting only transgenes that encode cytoplasmic cells, differing from the originally hypothesized translationalproteins and not affecting their native counterparts in the plant. repression. Although the exact mechanism remains unknown,This specificity hints at a highly refined regulatory system within our findings indicate a unique gene silencing process inplant sperm cells, one that discerns between endogenous (natu-sperm cells, contributing important insights to the scientificral) and exogenous (introduced) genetic material.community. GESENI presents both a challenge and an opportunity for Kawashimas finding is crucial because these silencedplant gene editing. On one hand, it complicates the use of genes could mislead interpretations of experimental results,transgenes as tools for understanding plant biology. On the posing a significant obstacle in plant reproductive research. other, it opens a new area of exploration. Understanding GESENI 42/ SEEDWORLD.COMINTERNATIONAL EDITION 2024'