Muscle and connective tissue progenitor populations show distinct Twist1 and Twist3 expression profiles during axolotl limb regeneration

Limb regeneration involves re-establishing a limb development program from cells within adult tissues. Identifying molecular handles that provide insight into the relationship between cell differentiation status and cell lineage is an important step to study limb blastema cell formation. Here, using single cell PCR, focusing on newly isolated Twist1 sequences, we molecularly profile axolotl limb blastema cells using several progenitor cell markers. We link their molecular expression profile to their embryonic lineage via cell tracking experiments. We use in situ hybridization to determine the spatial localization and extent of overlap of different markers and cell types. Finally, we show by single cell PCR that the mature axolotl limb harbors a small but significant population of Twist1+ cells.

► Single cell PCR molecular profiling of blastema subtypes.
► Isolation of Twist1 and Twist3 orthologs from axolotl.
► Twist1 and Twist3 expressed in lateral plate mesoderm derived blastema cells.
► Chondrogenic blastema cells co-express Twist1 and Sox9.
► Dermal blastema cells co-express Twist1 and Twist3.