PT - JOURNAL ARTICLE AU - Zhaoyuan Liu AU - Yaqi Gu AU - Svetoslav Chakarov AU - Camille Bleriot AU - Xin Chen AU - Amanda Shin AU - Weijie Huang AU - Regine J. Dress AU - Charles-Antoine Dutertre AU - Andreas Schlitzer AU - Jinmiao Chen AU - Honglin Wang AU - Zhiduo Liu AU - Bing Su AU - Florent Ginhoux TI - Fate mapping via Ms4a3 expression history traces monocyte-derived cells AID - 10.1101/652032 DP - 2019 Jan 01 TA - bioRxiv PG - 652032 4099 - http://biorxiv.org/content/early/2019/05/27/652032.short 4100 - http://biorxiv.org/content/early/2019/05/27/652032.full AB - Most tissue-resident macrophage (RTM) populations are seeded by waves of embryonic hematopoiesis and are self-maintained independently of a bone-marrow contribution during adulthood. A proportion of RTMs, however, is constantly replaced by blood monocytes and their functions compared to embryonic RTM remains unclear. The kinetics and extent of the contribution of circulating monocytes to RTM replacement during homeostasis, inflammation and disease is highly debated. Here, we identified Ms4a3 as a specific marker expressed by granulocyte-monocyte progenitors (GMPs) and subsequently generated Ms4a3TdT reporter and Ms4a3Cre-RosaTdT fate mapper models to follow monocytes and their progenies. Our Ms4a3Cre-RosaTdT model traced efficiently blood monocytes (97%) and granulocytes (100%), but no lymphocytes or tissue dendritic cells. Using this model, we precisely quantified the contribution of monocytes to the RTM pool during homeostasis and inflammation. The unambiguous identification of monocyte-derived cells will permit future studies of their function under any condition.