When the block is released and a bolus of RA is simultaneously administered the accumulated spermatogonia progress through the differentiation pathway in complete synchrony and maintain that synchrony with regard to stages of the cycle of the seminiferous epithelium for several months.
At the same time, in insisting that the emancipated society must be capable of presenting itself as a totality for its subjects, Lukács is unable to discover any resources for progress in the differentiation of social spheres (Arato and Breines 1979: 155).
Plxdc2 alone may not be sufficient to enable these cells to progress along the differentiation pathway, which may require further molecular events absent in our culture conditions.
Epidermal keratinocytes undergo two transitions regarding the proliferative state as they progress along the differentiation programme: i) when daughters of the stem cells in the basal layer enter a clonal expansion phase of rapid proliferation and become what has been defined as transit amplifying cells (TAC); and ii) when these cells cease to proliferate and undergo terminal differentiation.
Several recent studies suggest that nuclear structure experiences tremendous morphological alterations when ES cells progress along the differentiation axis.
We followed the progress of the differentiation process by monitoring cell morphology, as well as protein and transcript levels of ESC- and NPC-specific markers.
Here, we show that the microtubule array in myoblasts is highly motile and becomes increasingly parallelised and immobilised as cells progress through the differentiation programme.
As further proof of C2C12 myoblast differentiation, the expression level of Pax7, which is a skeletal muscle stem cell marker, became reduced concomitant with the progress of the differentiation program.
Note the complexity; the map contains sufficient concept relationships to illustrate the theme, but it also has a reasonable hierarchy to show progress in the differentiation of the knowledge structure, as well as cross-linkages between and within the micro maps.
This may be one difference between our own results and those of Jain et al. [ 19], namely that in our system an acquired resistance to apoptosis is required from the outset, but once this is in place and stays in place, tumours develop and progress whatever the differentiation status of these cells.
