||Mouse Mus musculus
||Krueger A, Ziętara N, Łyszkiewicz M. T Cell Development by the Numbers. Trends Immunol. 2017 Feb38(2):128-139. doi: 10.1016/j.it.2016.10.007 p.130 bottom paragraphPubMed ID27842955
|| D.E. Wright, et al. Physiological migration of hematopoietic stem and progenitor cells Science, 294 (2001), pp. 1933-1936 DOI: 10.1126/science.1064081PubMed ID11729320
||P.130 bottom paragraph: "The numbers of candidate TSPs [thymus-seeding progenitors] circulating in peripheral blood are extremely small. Thus, blood from a mouse contains approximately 180 MPPs [multipotent progenitors], 600 circulating T lineage-committed progenitors, and 180 CLPs [common lymphoid progenitors][BNID 113822]. It remains to be established whether progenitor numbers in peripheral blood are actively maintained through controlled release from BM [bone marrow] or passively due to a lack of survival factors [ref 23]. The residence time of HSCs [hematopoietic stem cells] and progenitors in circulation was estimated to be in the range of only 6 min, suggesting that peripheral blood does not constitute a conductive environment for BM-derived progenitors [primary source]."