life inspired

"Collective behavior comes through the ability of neighboring objects to communicate and interact with each other. Villar et al. [...] produced three-dimensionally patterned, interconnected networks of lipid-bounded structures functionalized with transmembrane proteins, which allowed electrical communication along specific pathways." Full article @ Science

Labels: biomimetics, collective behavior, development, self-assembly

"Development, regeneration, and even day-to-day physiology require plant and animal cells to make decisions based on their locations. The principles by which cells may do this are deceptively straightforward. But when reliability needs to be high—as often occurs during development—successful strategies tend to be anything but simple. Increasingly, the challenge facing biologists is to relate the diverse diffusible molecules, control circuits, and gene regulatory networks that help cells know where they are to the varied, sometimes stringent, constraints imposed by the need for real-world precision and accuracy." Full review @ Science

Labels: cells, development

"During development, cells undergo a unidirectional course of differentiation that progressively decreases the number of cell types they can potentially become. Stem cells, however, keep their potential to both proliferate and differentiate. A very important issue then is to understand the characteristics that distinguish stem cells from other cell types and allow them to conduct stable proliferation and differentiation. Here, we review relevant dynamical-systems approaches to describe the state transition between stem and differentiated cells, with an emphasis on fluctuating and oscillatory gene expression levels, as these represent the specific properties of stem cells. Relevance between recent experimental results and dynamical-systems descriptions of stem cell differentiation is also discussed." Full perspective @ Science

Labels: attractor behavior, complexity, development, dynamical systems, epigenetic landscape, modeling

"The spatial organization of cell fates during development involves the interpretation of morphogen gradients by cellular signaling cascades and transcriptional networks. Recent studies use biophysical models, genetics, and quantitative imaging to unravel how tissue-level morphogen behavior arises from subcellular events. Moreover, data from several systems show that morphogen gradients, downstream signaling, and the activity of cell-intrinsic transcriptional networks change dynamically during pattern formation. Studies from Drosophila and now also vertebrates suggest that transcriptional network dynamics are central to the generation of gene expression patterns. Together, this leads to the view that pattern formation is an emergent behavior that results from the coordination of events occurring across molecular, cellular, and tissue scales. The development of novel approaches to study this complex process remains a challenge." Full review @ Science

Labels: development, gene regulation, morphogenesis

"The Turing, or reaction-diffusion (RD), model is one of the best-known theoretical models used to explain self-regulated pattern formation in the developing animal embryo. Although its real-world relevance was long debated, a number of compelling examples have gradually alleviated much of the skepticism surrounding the model. The RD model can generate a wide variety of spatial patterns, and mathematical studies have revealed the kinds of interactions required for each, giving this model the potential for application as an experimental working hypothesis in a wide variety of morphological phenomena. In this review, we describe the essence of this theory for experimental biologists unfamiliar with the model, using examples from experimental studies in which the RD model is effectively incorporated.". Full review @ Science

Labels: complex systems, development, dynamical systems, reaction-diffusion, turing

It's not easy making a human. Getting from a fertilized egg to a full-grown adult involves a near-miracle of orchestration, with replicating cells acquiring specialized functions in just the right places at the right times. So you'd think that, having done the job once, our bodies would replace cells when required by the simplest means possible. Oddly, they don't. Our tissues don't renew themselves by mere copying, with old skin cells dividing into new skin cells and so forth. Instead, they keep repeating the laborious process of starting each cell from scratch. Now scientists think they know why: it could be nature's way of making sure that we don't evolve as we grow older. Full Story @nature.com

Labels: development, evolution, multicellular