Role of the Nail and Dorsoventral Patterning in Regeneration

The study investigates the role of nails and dorsoventral patterning in fingertip regeneration, focusing on mice lacking nails and dorsoventral patterning (LARM1/2). It finds that nail-less mice cannot regenerate their fingertips, indicating that the presence of a nail is crucial for this process, independent of dorsoventral polarity. Additionally, the gene Lmx1b, which is associated with limb dorsalization, is expressed in the dermis beneath the nail and in the blastema, suggesting its potential direct involvement in fingertip regeneration, separate from dorsoventral patterning.