Localization of Islet-1-positive cells in the healthy and infarcted adult murine heart.

The transcription factor Islet-1 is a marker of cardiovascular progenitors during embryogenesis. The isolation of Islet-1-positive (Islet-1(+)) cells from early postnatal hearts suggested that Islet-1 also marks cardiac progenitors in adult life. Objective: We investigated the distribution and identity of Islet-1(+) cells in adult murine heart and evaluated whether their number or distribution change with age or after myocardial infarction.