Segmentation in vertebrates: clock and gradient finally joined

Segmentation in vertebrates: clock and gradient finally joined.

The vertebral column is derived from somites formed by segmentation of presomitic mesoderm, a fundamental process of vertebrate embryogenesis. Models on the mechanism controlling this process date back some three to four decades. Access to understanding the molecular control of somitogenesis has been gained only recently by the discovery of molecular oscillators (segmentation clock) and gradien...

Head segmentation in vertebrates

Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, an...

Cancer and the circadian clock: has the time finally come?

W ithout the concept of time, there would be no physics, chemistry, or geology, but in medicine, time often gets short shrift. Yet in recent decades a small cadre of clinical investigators has found associations between the body's daily rhythms and the effectiveness of cancer treatment. Working in tandem, biologists have dissected the molecular underpinnings of the human circadian clock, a feed...

Oblivious Gradient Clock Synchronization

We study the gradient clock synchronization (GCS) problem, in which the worst-case clock skew between neighboring nodes has to be minimized. In particular, we consider oblivious clock synchronization algorithms which base their decision on how to adapt the clock solely on the most accurate timing information received from each neighbor. For several intuitive clock synchronization algorithms, wh...

Modeling of somitic segmentation in vertebrates