Related Experiment Video
Updated: Jun 14, 2026
14:27
A Cell-Free Assay Using Xenopus laevis Embryo Extracts to Study Mechanisms of Nuclear Size Regulation
Published on: August 8, 2016
Experimental evolution of cellular miniaturization reveals a putative mechanism for cell size evolution
Ana Garoña1, Morgane V Lemos1, Andrea Giometto2
1Gulbenkian Institute for Molecular Medicine, Oeiras 2780-156, Portugal.
Summary
Cell size homeostasis evolves to support diverse cell volumes. Researchers found that yeast cells can dramatically decrease in size over 1,500 generations without impairing function, revealing evolutionary plasticity.
Area of Science:
- Cell biology
- Evolutionary biology
- Genetics
Background:
- Cell volume is crucial for physiological function and is maintained by cell size homeostasis.
- Significant evolutionary divergence in cell size exists, but the mechanisms supporting this diversity without compromising cellular function are not fully understood.
Purpose of the Study:
- To investigate how cell size homeostasis evolves to accommodate drastic size changes.
- To identify genetic mechanisms underlying cell size reduction and its impact on cellular fitness in *Saccharomyces cerevisiae*.
Main Methods:
- Experimental evolution of *Saccharomyces cerevisiae* for 1,500 generations to select for smaller cell size.
- Whole-genome sequencing to identify causative mutations.
- Genetic perturbations and pathway analysis involving Cln3, Sch9, and Rim15.
Main Results:
- Achieved a fourfold reduction in modal cell volume in evolved yeast populations.
- Evolved lines maintained robust size homeostasis and high fitness despite significant size decrease.
- Identified mutations in G1 cyclin Cln3 and TOR pathway effector Sch9 as key drivers of cell size reduction, modulated by the Rim15 signaling cascade.
Conclusions:
- Cell size homeostasis exhibits significant evolutionary plasticity, allowing for substantial volume reduction without severe growth defects.
- The identified genetic pathways (Cln3, Sch9, Rim15) provide a mechanism for the evolution of eukaryotic cell size diversity.
Related Concept Videos
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
02:36Cells Coordinate Growth and Proliferation
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
02:36Cells Coordinate Growth and Proliferation
Cell size is a significant factor impacting cellular design, function, and fitness. There exists some internal coordination by which cells double their masses before division, thus, achieving homeostasis. Coordination between cell growth and proliferation depends on the checkpoints in between cell cycle phases. Loss of coordination or failure in the checkpoint mechanism can drive the cell to uncontrolled growth and loss of cellular function. Like dividing cells that coordinate cellular growth,...
01:23Cellular Adaptation I: Introduction and Atrophy
Cells can adapt to environmental changes to maintain function and avoid injury, a process called cellular adaptation. Adapted cells exist in a reversible intermediate state with changes in size, number, phenotype, metabolism, or function. These responses help cells meet altered physiological or pathological demands; for example, enlargement of breast and uterine tissues during pregnancy. Early adaptations may enhance function, but persistent stress eventually causes tissue damage.Types of...
03:21Genome Size and the Evolution of New Genes
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
03:21Genome Size and the Evolution of New Genes
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.