Selfish genes are very interesting phenomena, if too often misunderstood. (They are not “genes for selfishness.”) Animal genomes are overflowing with selfish mobile elements and their debris, but for pure devious self-interest, it’s hard to top toxin-antidote systems. These systems deliver a deadly genetically-encoded toxin to offspring, along with the antidote. The result is a system that ensures its own propagation, because whenever the toxin gene gets separated from the antidote gene*… you know the rest. How can such a…

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Complex cognitive tasks, such as value-based decision-making, can be influenced by sex and by sex steroids, but surprisingly little is known about the nature of these influences or how they happen. This is due, at least in part, to the fact that decades of research looked only at male subjects. In addition, however, there are formidable challenges facing experimenters who aim to explore the effects of sex steroids (such as estrogens) in the brain and behavior. In the case of…

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Human pathogens are diverse (bacteria, viruses, parasites) and destructive. Controlling and killing them is a major goal of humanity, hindered by (among other things) the sophisticated arsenals that pathogens have acquired over millions of years of evolutionary arms races with us. So it follows that we are keen to learn more about pathogen weaponry. A fascinating new preprint presents a powerful new resource in this struggle, with this added angle: the authors seek to not only block pathogenic weapons, but…

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RNA polymerase II is lovingly called “Pol II” by biologists. It’s an unassuming name (maybe a sequel to a blockbuster about a politician or a poltergeist) for a protein that is one of the most central and essential machines of eukaryotic life. Pol II is the main player in transcription, the process by which DNA sequences are read into messenger RNA. It’s hard to imagine a cell staying alive without it, and in fact “prolonged inhibition of RNA Pol II…

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In my last snippet, I wrote about a preprint on antimicrobial peptides as sleep modulators, which got me thinking more generally about interactions between the immune system and behaviour. Growing evidence shows extensive immune system-to-brain signalling and indicates that behavioural changes (like sleeping more and eating less) are not just side effects of being ill. There’s also evidence of signalling going the other way – from brain to immune system (e.g., stress modulates immunity), although this is less well understood.…

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Mitochondria are a bit strange. It’s popular to call them the “powerhouses of the cell,” and that’s true. But they’re also long-ago-domesticated free-living organisms that insist to this day on running their own genetic show, with a private genome and dedicated systems for gene expression. Perhaps understandably, biologists have long pictured the inner mitochondrial compartment (the matrix) as a relatively uniform space where all steps of mitochondrial gene expression—from DNA replication to protein synthesis—happen simultaneously. And yet, given that mitochondria…

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It’s that time of year again – it feels like half the people I know are ill, some forced to stay at home and “sleep it off”. It makes sense that we sleep more when we’re ill, and we know some of the molecular players involved: as early as the 1980s, studies in mammals revealed a role for cytokines, which are hormone-like signalling molecules released during illness. More recently, studies in nematode worms and fruit flies have implicated antimicrobial peptides…

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A common metaphor for a brain is that of a digital computer, with inputs and outputs and computations happening in between. The metaphor has its problems but there is no doubt about this: brains (neurons) perform computation. When reading a recent Science Advances paper about the computational capacity of life (all of life), I learned that the computational capacity of neurons has been assumed to account for the full computational capacity of life. This assumption excludes nearly all of the…

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In just a few years, our understanding of mutations in human cells has exploded. Huge studies have mapped their characteristics and genomic locations, adding up to a “landscape” of mutation. This work, especially in cancer, has generated catalogues of mutational “signatures” that represent patterns of mutation and can yield clues to mutations underlying disease. One of these signatures, with the license plate-sounding name SBS5, is a standout for at least three reasons: 1) it is very common, in cancers and…

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In my last snippet, I speculated that AI tools recently published in Science and Nature (the “logos” method and an RFdiffusion-based method) could be used to design a protein targeting the intrinsically disordered and toxic N-terminal region of the prion protein. Yet within a week, Nature Biotechnology published a tool that might be even better suited to the task. PepMLM (“Peptide binder design algorithm via Masked Language Modeling”) is a protein language model that designs peptides that will bind to…

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