🧬 AI-Designed Life with a 19–Amino Acid Alphabet (Issue 6797, published online ahead of 6800) https://www.science.org/doi/10.1126/science.aeb5171

All natural organisms use the same 20 amino acids as building blocks for proteins, but this work explored building a cell from a 19–amino acid alphabet. Liu et al. used computational protein design and synthetic biology to remove all isoleucine residues from the ribosomal proteins in a bacterium. AI-based protein language models and structure-based models were critical to the success of this effort, highlighting the power of generative design. This work provides a path toward building genetically recoded cells with simplified components and sheds light on the biochemical constraints that may have shaped early evolution. Science

🧠 The Oscillatory Biology of Sleep: Linkage to Dementia — Maiken Nedergaard (Review, pp. 821–826) https://www.science.org/doi/10.1126/science.aeg2276

Thirteen years after the initial publication defining the glymphatic system, this review critically reappraises the role of its dysfunction in Alzheimer's disease. It reviews current approaches to assess glymphatic function clinically, which capture different features of perivascular fluid dynamics or their results, and addresses the absence of clinically suitable imaging approaches to measuring glymphatic exchange in the human brain as an obstacle to developing and evaluating therapeutics. Science

🪰 Gut-Brain Amino Acid Sensing in Drosophila — Boram Kim, Seongju Lee et al. (Research Article) https://www.science.org/doi/10.1126/science.adv3355

A deficit in dietary protein elicits a nutrient-specific appetite, yet the underlying mechanisms remain poorly understood. This work identifies coordinated neuronal and systemic mechanisms in Drosophila that drive an essential amino acid (EAA)–specific appetite response, involving a complex interplay of neuronal and hormonal gut-brain responses. Science

🌿 Deep-Time Landscape of Plant Cis-Regulatory Sequence Evolution — Kirk R. Amundson, Anat Hendelman et al. (Research Article) https://www.science.org/doi/10.1126/science.adt8983

Developmental gene function is often conserved over deep time, but cis-regulatory sequence conservation is difficult to identify. Rapid sequence turnover, paleopolyploidy, structural variation, and limited phylogenomic sampling have impeded conserved non-coding sequence discovery. This study uses comparative genomics across plant lineages — including tomato — to map how gene-regulatory elements evolve over millions of years, with direct implications for crop improvement. Science

🤖 Generative AI Use and Misuse in Higher Education — Igor Chirikov, Ivan Smirnov & René F. Kizilcec (Commentary, pp. 818–820) https://www.science.org/doi/10.1126/science.aec5115

The debate about the impact of generative AI on higher education is polarized — some portray GenAI as normalizing cheating at scale, whereas others argue that misconduct patterns have changed little. This study addressed the gap with survey data from 95,513 students in a representative sample of 20 major public research-intensive universities in the United States, using an indirect method to capture sensitive behaviors such as cheating across fields. Science

The cover story on ancient antiviral immunity shared between bacteria and humans is the issue's biological centerpiece, though it doesn't appear to have a direct AI component. The AI-in-life-sciences highlight is clearly the 19-amino-acid cell paper, which explicitly credits protein language models (AI) as essential to its success.