10 - 14 days
||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.132 2nd paragraphPubMed ID27842955
|| N. Zietara, et al. Multicongenic fate mapping quantification of dynamics of thymus colonization J. Exp. Med., 212 (2015), pp. 1589-1601 doi: 10.1084/jem.20142143  D.L. Foss, et al. Functional demonstration of intrathymic binding sites and microvascular gates for prothymocytes in irradiated mice Int. Immunol., 14 (2002), pp. 331-338PubMed ID26347471, 11867569
||Primary source  abstract: "...[investigators] established multicongenic fate mapping combined with mathematical modeling to quantitate individual events of thymus colonization."
||P.132 2nd paragraph: "It remains an open question how thymus colonization is regulated. Based on parabiosis experiments it has been proposed that thymic niches open periodically at 3–4-week intervals [ref 39]. However, niche saturation through intrathymic transfer and sequential congenic fate-mapping experiments indicated a periodicity of 10–14 days, that is, an individual thymus acquires maximum receptivity for colonization every 10–14 days with a refractory period in between [primary sources]. Interestingly, this period coincides with the average lifetime of an ETP [early T lineage progenitors] as well as with the time of residence of transplanted thymocytes at the corticomedullary junction (CMJ), which constitutes the region of thymocyte entry [refs 41,42]."