Amoeba
A motile cell disperses, explores its environment and begins a new developmental cycle.
ICHTHYOSPOREA / MAIN EXPERIMENTAL SYSTEM
Creolimax
fragrantissima
One cell.
A generation forming within.
Actin in green · nuclei in blue · Multicellgenome Lab
MULTICELLULAR DEVELOPMENT
An amoeba becomes
a multicellular sphere.
Creolimax fragrantissima begins as a motile amoeba. It settles, grows and repeatedly divides its nuclei inside one expanding cell. Then, in a coordinated transformation, it builds many daughter cells and releases a new generation.
DEVELOPMENT IN MOTION
One boundary.
Many futures.
THE LIFE CYCLE
From amoeba
to coenocyte—and back.
Growth
The cell settles and expands while repeated, synchronized nuclear divisions build a coenocyte.
Cellularization
The shared cytoplasm is partitioned around its nuclei, creating many daughter cells at once.
Release
New amoebae leave through openings in the parental wall and begin the cycle again.
WHY IT MATTERS
Could animal development
have begun inside one cell?
Creolimax offers a living version of a provocative evolutionary route: multicellularity arising through the cellularization of a multinucleate ancestor. Its synchronized nuclei, temporally distinct cell states and motile amoebae let us examine how developmental programmes could predate animals.
A HISTORIC FIRST
The first genetically manipulated
unicellular relative of animals.
In 2013, Creolimax became the first close unicellular relative of animals in which both cell transformation and gene silencing were established.
This made it possible to label nuclei in living cells, reveal strictly synchronized nuclear divisions and test gene function experimentally.
TRANSFECTIONsiRNAMORPHOLINOLIVE IMAGING
CELL-TYPE PROGRAMMES
Different stages.
Different molecular identities.
Synchronized nuclei
Nuclear divisions occur in a strict rhythm before cellularization begins.
Stage-specific expression
Amoeboid and multinucleate stages activate distinct transcriptional programmes.
Complex regulation
Alternative splicing and long non-coding RNAs contribute to a dynamic unicellular life cycle.
Actin architecture
Cytoskeletal reorganization accompanies the conversion of one cytoplasm into many cells.
FOUNDATIONAL WORK
Isolation.
Manipulation.
Regulation.
2008
Discovering Creolimax
Marshall and colleagues repeatedly isolated the organism from marine invertebrates and described its distinctive amoeboid dispersal stage.
↗2013The first transfection and gene silencing
Experimental manipulation revealed synchronized nuclear division and established Creolimax as a model for the cellularization route to multicellularity.
↗2015Resolving its evolutionary position
Taxon-rich phylogenomics clarified the placement of ichthyosporeans within the closest relatives of animals.
↗2015Complex regulation before animals
Transcriptomics uncovered stage-specific programmes, alternative splicing and long non-coding RNAs across the life cycle.
↗GENOME & RESOURCES
Explore the system.
CONTINUE EXPLORING
