Cre recombinase microinjection for single-cell tracing and localised gene targeting

Area of Science:

• Developmental biology
• Molecular biology
• Genetics

Background:

• Understanding embryonic development requires effective cell tracing and manipulation techniques.
• Current methods like lipophilic dye microinjections, viral transfection, and iontophoresis have limitations in efficiency and skill requirement for single-cell labeling.
• Mapping progenitor cell origins is crucial for understanding organogenesis and congenital defects.

Purpose of the Study:

• To introduce a novel method for lineage tracing and gene manipulation in post-implantation mouse embryos.
• To enable single-cell labeling and clonal analysis of progenitor cells.
• To investigate the role of specific genes, such as Mycn, in embryonic development.

Main Methods:

• Microinjection of cell-permeant Cre recombinase (TAT-Cre).
• Titration of TAT-Cre dose for achieving single-cell recombination and clonal analysis.
• Application of TAT-Cre in Mycnflox/flox embryos for gene ablation studies.

Main Results:

• Successfully mapped the fate of undifferentiated progenitors to specific heart chambers.
• Achieved single-cell recombination, enabling clonal analysis of nascent mesoderm progenitors.
• Demonstrated that Mycn plays a cell-autonomous role in maintaining cardiomyocyte proliferation.

Conclusions:

• TAT-Cre microinjection is an efficient tool for lineage tracing and gene manipulation in mouse embryos.
• This technique facilitates the identification of cell progenitors and gene networks critical for organ development.
• The findings contribute to understanding the origins of congenital heart defects and other developmental abnormalities.