There have also been studies in rats in which ESCs or fetal-derived neural stem cells and progenitor cells (undifferentiated cells; similar to stem cells but with narrower differentiation capabilities) have been transplanted into regions of the brain damaged by stroke.
The chromosomal signatures of selection can take the form of narrow regions of differentiation (A), large genomic islands (B), or shoulders of differentiation (C and D) centered on the selected loci.
We cannot fully reconcile this observation with reports of very narrow regions of differentiation on 2R in another population sample from Guinea-Bissau (Weetman et al. 2012), as differences in findings between the studies may result from fine differences in spatial or temporal sampling or in the sensitivity of the respective assays.
This result may not be so surprising because transient reporter gene assays are often a poor proxy for the activities of regulatory elements integrated in the genome, which can be active in narrow windows of development, differentiation and cellular conditions [ 20].
On SBFT, there is luminal narrowing with irregularity, but differentiation from chronic disease is not always possible [14].
Previous work has shown that precise levels of Oct4 transcript and protein are required for ES cell maintenance; raising or lowering levels within a narrow window is sufficient to induce differentiation or de-differentiation, respectively [14].
Moreover, if not eliminated by Catalase or Gpx, H2O2 can activate signaling pathways, potentially involved in cell division and differentiation within a narrow window of development.
In the horse at least, these observations also highlight the very narrow period in development when differentiation events may be initiated and demonstrate the crucial importance of carefully assessing tissue responses at a number of carefully selected windows in early placental development.
As quality, access to talent, supply chains, pricing and cost efficiencies all narrow into a slim band of differentiation, innovation will become a hotbed of competition.
During embryonic stem (ES) cell differentiation, the NE lumen becomes narrower in differentiated cells and nesprin-1 KASH isoforms become significantly upregulated.
