Lymphocyte Content and Proliferative Capacity of Serially Transplanted Mouse Bone Marrow

Relationship between donor age and the replicative lifespan of human cells in culture: A reevaluation

“…27). Support for the view that the mechanisms responsible for aging in vitro are also active in vivo is found in the fact that normal cells, serially transplanted to compatible hosts, exhibit a proliferative decline (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38). A number of investigators have presented data suggesting that this loss of proliferative activity is expressed in vitro as decreased outgrowth of cells from biopsies, reduced clone size distribution, and decreased replicative lifespan (4,5,10,11,22).…”

“…Nevertheless, serial transplantation studies have clearly established that the proliferative capacity of cells can be diminished in vivo (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38). If replicative potential in vivo is thus limited, and cells in vivo are at least occasionally stimulated to divide, it is reasonable to expect that the proliferative ages of cells in vivo will vary depending on their proliferative history.…”

Normal Production of Erythrocytes by Mouse Marrow Continuous for 73 Months

“…Much of current research in aging is based on the hypothesis that this deterioration is intrinsically timed within each cell type (1)(2)(3)(4)(5). This hypothesis is supported by the limited proliferative capacity in vitro of human diploid fibroblasts (1,6,7) and the limited proliferative capacities in vivo of transplanted mouse mammary gland (8) and marrow (9,10). These experiments do not completely verify the hypothesis because even the limited proliferative capacities of these cell types may have been sufficient for them to function normally for much longer than the lifespans of their donors.…”

Extensive in vivo self-renewal, long-term reconstitution capacity, and hematopoietic multipotency of Pax5-deficient precursor B-cell clones

“…The one, short-term HSC (ST-HSC), possesses limited self-renewal potential, pluripotency, and only short-term reconstitution capacity, while the other, long-term HSC (LT-HSC) has long-term selfrenewal and hematopoietic reconstitution capacity. 6 While HSCs have been found to persist throughout life in almost constant numbers, 7,8 and while 3 to 5 consecutive transplantations of HSCs into lethally irradiated hosts have suggested that they might undergo 80 to 200 divisions, [9][10][11][12][13] their in vitro capacity for selfrenewal appears limited to about 20 cell divisions. 14 Therefore, the self-renewal capacity of LT-HSCs appears to be strongly dependent on conditions, which can be provided by the host in vivo, but are insufficient with current in vitro culture conditions.…”