ALFA-K: Local adaptive mapping of karyotype fitness landscapes
Nature CommunicationsTL;DR
Imagine a tumor is a team of players in a video game, where each player's character build (their set of chromosomes) is slightly different. Some builds are strong and fast, while others are weak. This study created a computer program, ALFA-K, that watches the game and creates a 'map' of the game world. The hills on the map represent powerful character builds that help the team win (high fitness), and the valleys are weak builds that get eliminated. ALFA-K is so smart it can not only map the builds it sees, but it can also predict which new, unseen builds are likely to be powerful. This helps scientists understand the rules of cancer's 'game' and how it adapts to challenges like chemotherapy.
Despite its critical role in tumor evolution, a detailed quantitative understanding of the evolutionary dynamics of aneuploidy remains elusive. Here we introduce ALFA-K (Adaptive Local Fitness landscapes for Aneuploid Karyotypes), a method that infers chromosome-level karyotype fitness landscapes from longitudinal single-cell data. ALFA-K estimates fitness of thousands of karyotypes closely related to observed populations, enabling robust prediction of emergent karyotypes not yet experimentally detected. We validate ALFA-K’s performance using synthetic data from an agent-based model and empirical data from in vitro and in vivo passaged cell lines. Analysis of fitted landscapes suggests several key insights: (1) Whole genome doubling facilitates aneuploidy evolution by narrowing the spectrum of deleterious copy-number changes; (2) Environmental context and cisplatin treatment significantly modulate the fitness impact of these changes; (3) Fitness effects of copy-number changes depend on parental karyotype; and (4) Chromosome mis-segregation rates strongly influence the predominant karyotypes in evolving populations.
- 1Whole genome doubling facilitates aneuploidy evolution by narrowing the spectrum of deleterious copy-number changes.
- 2Environmental context and cisplatin treatment significantly modulate the fitness impact of copy-number changes.
- 3Fitness effects of copy-number changes depend on parental karyotype.
- 4Chromosome mis-segregation rates strongly influence the predominant karyotypes in evolving populations.
Baby chicks pass the bouba-kiki test challenging a theory of language
Imagine you hear the made-up words "bouba" and "kiki" - which one sounds round and soft, and which sounds sharp and spiky? Most people say "bouba" sounds round and "kiki" sounds sharp. This is called the bouba-kiki effect, and scientists thought it might be special to humans and related to how we developed language. But this study found that baby chickens, just hours after hatching, make the same connections! When they heard "bouba-like" sounds, 80% of the chicks walked toward round, curved shapes rather than spiky ones. This suggests that connecting sounds with shapes isn't learned or uniquely human - it might be a basic way that many animals' brains work, going back hundreds of millions of years in evolution.
Single-minus gluon tree amplitudes are nonzero
Imagine tiny particles called gluons are like spinning tops. Their spin can be in one of two directions, which physicists call 'plus' or 'minus'. For decades, the rulebook seemed to say that you could never have a situation where just one gluon was spinning 'minus' and all the others were spinning 'plus' — that outcome was thought to be zero. This paper found a loophole. Under very specific, purely mathematical conditions that don't exist in our physical reality but are useful for calculations, this interaction can happen. The researchers wrote down the exact recipe for it, fixing a small but important detail in our fundamental rulebook for how the universe works.
Sub-part-per-trillion test of the Standard Model with atomic hydrogen
Scientists made an incredibly precise measurement of light emitted by hydrogen atoms that tested one of physics' most fundamental theories - the Standard Model - to an accuracy of 0.7 parts per trillion. This measurement also resolved a long-standing disagreement about the size of protons by confirming the smaller value found in previous experiments with exotic atoms.
Liver exerkine reverses aging- and Alzheimer’s-related memory loss via vasculature
This discovery could lead to new treatments for age-related memory loss and Alzheimer's disease that don't require physical exercise. Instead of just telling people to exercise more, doctors might eventually be able to give patients the specific liver protein (GPLD1) or drugs that block TNAP to achieve the brain benefits of exercise. This is especially important for elderly or disabled people who cannot exercise regularly but still want to protect their memory and cognitive function.