Scientists mapped 11,692 gene knockdowns in stem cells — all in one atlas

Key Findings

🍄 Prime Editing Now Works in Fungi — and Found 8 New Molecules

• Researchers developed fPE7max, a prime editing platform optimized for filamentous fungi, achieving average editing efficiency near 90% across multiple species and genomic sites.
• By editing upstream regulatory sequences in a key fungal gene, they activated dormant biosynthetic pathways — metabolomic profiling turned up 18 metabolites, including 8 previously unreported structures, 3 of which showed cytotoxic activity.

🫁 A Splicing Mutation in Lung Cancer Is Actually a Rescue Act

• A specific KRAS mutation (G12S) causes the cell to skip a critical exon, producing a nonfunctional KRAS protein — a self-defeating oncogenic event. But a co-occurring splicing factor mutation (U2AF1-S34F) reverses that exon skipping and restores KRAS function, explaining why these two mutations are found together in patient tumors far more often than chance.
• A second pairing — KRAS Q61R and U2AF1 I24T — follows the same logic, confirmed experimentally.

🧠 Biodegradable Nanoparticles Deliver Gene Editing Deep Into the Brain

• A 200-member library of biodegradable ionizable lipids was screened in live mice via intrathecal injection (into the spinal canal, bypassing the blood-brain barrier). The lead candidate, P3B, drove widespread gene editing in neurons and astrocytes across multiple brain regions.
• Compared to a clinical benchmark lipid, P3B showed substantially higher editing efficiency, attenuated inflammatory responses, and a tolerability profile compatible with repeat dosing.

🦠 Engineered Salmonella Made Less Immunosuppressive With CRISPRi

• Salmonella used as a cancer immunotherapy normally injects proteins that suppress the host immune response after invading cells. Researchers used CRISPRi to dial down two of those effectors, shifting the downstream signaling: less immunosuppressive IL-10, more pro-inflammatory TNF-α, and increased cancer cell death.
• The study is the first demonstration that CRISPRi modulation of bacterial effectors can reshape mammalian cell physiology during bacterial therapy.

🌿 Transgene-Free Crop Editing Is Closing In on Regulatory-Friendly Precision

• A review of transgene-free genome editing in plants maps the current toolkit: direct delivery of ribonucleoprotein complexes, mRNA-based delivery, base editors, and prime editing — all approaches that modify the genome without leaving foreign DNA behind.
• The appeal is regulatory as much as scientific: edits made without stable foreign DNA integration are increasingly treated as non-GMO in several jurisdictions, opening a faster path for crop improvement.

🍋 The Gene That Makes Kumquats Sour (or Not) Has Been Identified

• By crossing a low-acid kumquat with a high-acid variety and mapping the offspring, researchers pinpointed a GRAS transcription factor — ChSCL9 — as a key regulator of citric acid accumulation. CRISPR-Cas9 knockout and overexpression experiments confirmed it directly represses two genes responsible for acidifying the fruit's vacuoles.
• The finding identifies an upstream regulator of fruit acidity and gives breeders a concrete molecular target for flavor engineering in citrus.