It should be noted, however, that the vast majority of neural precursor cells in a clonal neurosphere are neural progenitor cells (Morshead et al., 1994), which have decreased passaging ability and limited self-renewal.
Decreasing passage and digestion rates of potentially digestible NDF with increasing WCS increased the evacuated pool size of ruminal DM, apparently explaining the similar ruminal mat consistency among treatments.
The doubling rate was constant for up to 5 passages and decreased after passages 6-8.
The same study also demonstrated that doubling rate was constant for up to five passages and decreased after passages 6 to 8 [ 25].
However, TDLU-like structure formation dramatically decreased by passage 5. Importantly, forskolin was required for maintenance of an epithelial morphology in 2D culture (supplementary material Fig. S2B).
Consistent with previous work in murine as well as human MSCs, we found that adipogenic differentiation decreased with passage number [ 48- 51].
Since the loss of angiogenesis capability was proportional to the round of cell passage, we applied a statistical approach to identify genes with regressive expression patterns, i.e. their expression either increased or decreased over passage numbers.
Muraglia et al [ 35] isolated 185 clones of human MSCs and showed that 184 of these differentiated along an osteogenic lineage, whereas fewer clones showed chondrogenic or adipogenic potential, and the potentials of the latter decreased with passage number.
This multipotent population expresses the mammary stem cell marker CD49f, and in culture around 40% of CD49f+ cells were able to produce differentiated alveolar structures; however, cell viability and alveolar size decreased with passage number.
The yield of the Fc protein was not significantly decreasing from passage 1 to passage 30 indicating that BAC-based vectors provide stable long-term production of recombinant proteins.
