Biological aging
Cells change, tissues lose resilience and organs age at different rates. Which changes drive the others, and how do they become a whole-body process?
Molecular and cell biology
Within Molecular and cell biology · Search all subjects
Eukaryogenesis
Complex cells with nuclei descended from simpler ancestors. How did their internal compartments, mitochondria, and distinctive cellular organization come together?
Functions of sleep
Sleep is essential, but why do its benefits require a state in which an animal becomes less responsive to its surroundings?
Evolution of multicellularity
Cells have repeatedly evolved into organisms that live and reproduce together. What turns a group of cells into a coherent evolutionary individual?
Sex chromosome evolution
Some lineages keep the same sex chromosomes for vast spans of time; others replace them repeatedly. Why do their evolutionary paths differ so much?
Neural coding
Neural activity carries information, but which aspects of that activity does the brain actually use? A pattern readable by an analyst need not be the pattern used for behavior.
Genetic architecture of complex traits
Thousands of genetic variants can contribute to a trait, yet finding an association does not reveal how those variants work together to produce it.
Gene regulatory grammar
Cells with similar DNA can activate very different genes. How do regulatory sequences and cellular conditions specify when, where, and how strongly a gene is used?
Developmental robustness
Developing organisms often produce reliable structures despite molecular noise, genetic differences, and environmental changes. How is that reliability achieved?
Regeneration
Some animals rebuild lost body parts, while others mostly form scars. What determines whether damaged tissue can reconstruct an organized, functional structure?
Tumor dormancy
Cancer cells can persist quietly for years and later form a new tumor. What keeps them dormant, and what allows them to start growing again?
Antibiotic persistence
Some bacteria survive an antibiotic exposure without inheriting resistance to the drug. What allows these persister cells to survive and later resume growth?
Human microbiome causality
Microbial communities differ between people and are associated with many health conditions. Which differences change the host, and which simply reflect other changes?
Animal magnetoreception
Many animals use Earth’s magnetic field to orient themselves. How does that weak field become a signal their nervous systems can use?
Origin of the genetic code
Cells translate genetic sequences into proteins. How did a code and the machinery that reads it arise together?
Circadian temperature compensation
Most chemical reactions change speed with temperature. A plant’s daily clock can keep nearly the same rhythm. How do its components cooperate to do that?
Human X-chromosome inactivation
Developing cells can silence much of one X chromosome. How do human embryos establish which copy becomes inactive?
Escape from X-chromosome inactivation
An inactive X chromosome is not completely silent. Why do some genes escape, and why does that vary between tissues and cells?
Genome size evolution
Closely related organisms can carry very different amounts of DNA. What determines how genomes expand or shrink?
Intra-Golgi transport
The Golgi modifies cargo as it moves through the organelle. How is that traffic coordinated with the recycling of its resident proteins?
Bulky cargo export from the ER
Some cargo is too large for a conventional small transport vesicle. How does it leave the endoplasmic reticulum?
Nuclear pore selectivity
Nuclear pores admit some molecules and exclude others. How does their dynamic central barrier adjust to the cargo passing through?
Mammalian cell size homeostasis
Different mammalian cells maintain different sizes. What sets their target size and coordinates growth with division?
Organ growth termination
Organs slow their growth and reach characteristic sizes. How do local signals and the rest of the body coordinate that stopping point?