New tools to track cell lineages

Studying the development of embryonic tissues at a cellular resolution, resolving clonal relationships among the cells in an organ, will help to understand the formation of the different organs in normal and pathological conditions. Whereas there are already several methods to label clones available, they all have drawbacks and could suffer from either underestimating or overestimating the size of the clones. To minimize such mistakes, very few clones must be studied in a given specimen, impeding the study of generation, integration and relationship of multiple clones.

HFSP Long-Term Fellow Fernando García-Moreno and colleagues
authored on Thu, 03 April 2014

Fernando Garcia-Moreno of the University of Oxford and colleagues have just published a new paper in Development reporting CLoNe, a new method for clonal cell labelling in vivo, based on the combined electroporation into progenitor cells of plasmids encoding multiple fluorescent reporters, a Cre driver and a transposase. Twelve distinct fluorescent reporters (differing in their encoded fluorescent protein –mtSapphire, EGFP, EYFP, mCherry- and its subcellular localization) are combined to achieve, upon random integration and recombination, a high complexity of hues and subcellular colour combinations. Cre expression can be driven by ubiquitous or cell-specific promoters to refine tracing to specific progenitor populations, and the approach was tested in the mouse and chick embryonic telencephalon and in the chick limb bud. It is shown to permit long-term tracing through somatic integration of the reporter plasmids into the host cell genome, and to generate an unbiased colour distribution to maximize clone assignment.

Figure 1: Dorsal forebrain of E11 chick embryo labelled with CLoNe constructs. Cellular morphology, migratory movements and clonal relationships can be studied through combinatorial expression of fluorescent proteins.

Figure 2:  Clusters of chicken pallial progenitors share the same fluorescent pattern, indicative of clonal identity.

CLoNe is based on the use of cell-type specific Cre. It allows comparative analysis of progenitor cells across species by using evolutionarily significant genetic elements to activate Cre expression and it is suitable for various tissues, as evidenced in muscular and epithelial tissue, and systems across several vertebrate species.


The paper by Fernando Garcia-Moreno and colleagues featured on the cover of  Development, April 2014. Click on the image for explanation.

Reference

CLoNe is a new method to target single progenitors and study their progeny in mouse and chick. García-Moreno F, Vasistha NA, Begbie J, Molnár Z.  (2014) Development. 141(7):1589-98. doi: 10.1242/dev.105254.

Link to abstract

Supplementary Reading on the Node

Pubmed link