I also don't minimize the difficulty of being a stepparent, especially of a child whose dishonesty has jumped its developmental boundaries.
Moreover, local Notch activity can induce the formation of developmental boundaries as seen during wing margin formation in Drosophila [ 7- 9].
Beyond developmental boundaries, such as the AP boundary, it is conceivable that in situ carcinomas can generate similar border effects (Vidal et al., 2006; Vidal et al., 2010).
Thus, manipulation of certain receptors or signaling pathways may allow cells to escape their rigid developmental boundaries, while rendering them still capable of reaching a normal developmental endpoint.
2R-WGD is believed to greatly increase the morphological complexity (including developmental boundaries and gene functional modules) in the transition from basal chordates to vertebrates [ 38].
Models of periodic patterning seek to explain the developmental origin of boundaries separating adjacent repetitive structures and the maintenance of cellular compartments once formed [ 1- 8].
With the goal of identifying developmental fields or boundaries in the heart, Devine and colleagues perform lineage-tracing studies on cardiac progenitor cells, defined by expression of mesodermal markers, in late pre-gastrulation/early gastrulation mouse embryos.
However, Notch signaling also regulates additional developmental decisions, such as boundary formation between cell populations, cell proliferation, and cell death.
This work demonstrates that a developmental regulator coordinates chromatin boundaries with the transcriptional competence of the flanked region.
Cells along the osteogenic differentiation pathway may be artificially categorized as (1) undifferentiated MSCs, (2) osteo-chondro-progenitor cells, (3) pre-osteoblasts, and (4) osteoblasts; although in reality, a developmental continuum without distinct boundaries may exist [43].
