PM-R receptor supports formation of myeloid hematopoietic colonies in the presence of PRL.

Day-12.5 fetal liver hematopoietic progenitors from C57Bl6 and PRL-R KO mice were infected with MSCV retroviruses encoding the various receptors (P-R, PE-R, and PM-R), and 5 × 10⁴ cells were cultured in duplicate in methylcellulose medium with 500 ng/mL ovine prolactine (PRL) (panel A) or with EIT cocktail (panel B). Colonies were scored after 7 to 10 days. The results shown are the mean of 2 independent experiments. Types of colonies (CFU): ■, granulocyte-macrophage (-GM); ▤, burst-forming unit-erythroid (BFU-E); ▪, mixed (-GEMM); ▧, erythro-megakaryocyte (-EMK); ▥, granulo-megakaryocyte (-GMK); and ▨, megakaryocyte (-MK).