Much of the research to date on mammary epithelial differentiation has focused upon expression of milk protein genes, providing a somewhat distorted view of alveolar differentiation and secretory activation.
This observed plasticity of normal tissue stem cells has implications for tissue organization in general, and the view of rigid differentiation hierarchies of cells must be revised in light of these findings.
To obtain a more comprehensive view of bradyzoite differentiation, Buchholz and colleagues assayed the transcriptomes of type II (strain M4) bradyzoites [ 9].
Intra-tumor and inter-tumor heterogeneity of human breast cancer should no longer be viewed as a consequence of phenotypic drifting due to genetic instability, but also from the point of view of different differentiation repertoires available to the neoplastic cells in response to the tumor microenvironment, including reversion to a 'normal' phenotype (for an overview, see [ 4]).
A widely held view of the differentiation of mammalian ES cells entertains that, as cells exit pluripotency, they choose between fates that resemble NECT and PS from a naïve state under the influence of their local signalling environment that enforces a rearrangement of the pluripotency network (Loh and Lim, 2011; Thomson et al., 2011).
(C ) Top, an apical view of the sequential differentiation of eight photoreceptor (R1-R8) and four cone cell types (C1-C4) fromultipotentnt progenitor cells (grey) in an ommatidium.
Since the modern synthesis, our view of how population differentiation occurs in the wild is largely based on the advances made in population and quantitative genetics, especially with the advent and integration of genomics tools.
Although this hypothesis is certainly speculative at this point, it might help explain some other recent findings in Ar mutant mice (described below) that are puzzling according to a traditional view of exclusively local differentiation of the brain.
The conventional view of bone cell differentiation is that pluripotent or multi-potent stem cells commit to an osteoprogenitor lineage and then undergo a smooth, consistent, and well defined transition to produce differentiated osteoblasts.
A complementary view is that reprogramming of differentiation switched on a search mode and sorting of options.
