Skin Wounds in the MRL/MPJ Mouse Heal with Scar

In the 2006 study by Colwell et al., it was found that MRL/MpJ mice, which are capable of regenerating cartilage in ear punch wounds, do not heal isolated cutaneous wounds on their dorsum without scarring. The healing process of full-thickness skin wounds in MRL/MpJ mice was compared with C57bl/6 and Balb/c mouse strains, and despite complete reepithelialization by 48 hours and gross healing by 14 days, histological analysis at 14 and 28 days post-wounding showed dense collagen deposition and fibrosis in all strains. This indicated that MRL/MpJ mice's skin wounds healed with scars, in contrast to their ear wounds which healed by day 28 with regenerative features. The study highlighted the complexity of tissue regeneration and its variation across different body sites, suggesting that further research could help develop methods for scar-free healing in humans.