Hot off the presses! Jul 19 Dev Cell

The Jul 19 issue of the Dev Cell is now up on Pubget (About Dev Cell): if you're at a subscribing institution, just click the link in the latest link at the home page. (Note you'll only be able to get all the PDFs in the issue if your institution subscribes to Pubget.)

Latest Articles Include:

• A Decade of Developmental Cell
  - Dev Cell 21(1):1 (2011)
  
• Shifting Patterns: Merging Molecules, Morphogens, Motility, and Methodology
  - Dev Cell 21(1):2-4 (2011)
  We highlight crucial technological progress of the past ten years that permits quantitative analysis of cellular behavior. Adapting these methods to the study of embryogenesis will be essential to advance our understanding of development in the coming decade.
• Bridging Structure and Process in Developmental Biology through New Imaging Technologies
  - Dev Cell 21(1):5-10 (2011)
  Many unexpected discoveries in developmental biology have depended on advancement of imaging technologies to visualize developmental processes as they unfold across multiple spatial and temporal scales. This essay surveys the recent advances in imaging, highlighting emerging capabilities with an eye toward those poised to have the greatest impact on developmental biology.
• Can a Systems Perspective Help Us Appreciate the Biological Meaning of Small Effects?
  - Dev Cell 21(1):11-13 (2011)
  The study of dramatic phenotypes has been pivotal to elucidating biological mechanisms. Effectively approaching low-magnitude quantitative phenotypes, a common outcome of systematic loss-of-function studies, will be critical for understanding how individual components of cells interact to generate functioning systems.
• Beyond Stereospecificity: Liquids and Mesoscale Organization of Cytoplasm
  - Dev Cell 21(1):14-16 (2011)
  The cytoplasm is not a homogenous solution but instead consists of large dynamic assemblies that arise from transient molecular interactions. Some of these structures have been shown to represent liquid droplets of concentrated protein and RNA. Liquid phase separation of cytoplasm may be a fundamental principle of cytoplasmic organization.
• Enhancers: From Developmental Genetics to the Genetics of Common Human Disease
  - Dev Cell 21(1):17-19 (2011)
  In mammals, long-range gene regulation became apparent through simple Mendelian disease genetics in human and developmental genetics in the mouse. Can the insights into gene control, provided by the study of these enhancers, help us understand the functional significance of sequence variation associated with common/complex human disease and quantitative traits?
• The Impact of Developmental Biology on Pluripotent Stem Cell Research: Successes and Challenges
  - Dev Cell 21(1):20-23 (2011)
  Research on developmental pathways in model organisms provides key information on how to isolate, maintain, and differentiate human pluripotent stem cells. However, details of developmental pathways differ even across mammalian species. Full realization of the potential of stem cells will require more direct studies of human or primate developmental biology.
• Self-Organization of Animal Tissues: Cadherin-Mediated Processes
  - Dev Cell 21(1):24-26 (2011)
  Animal cells are capable of self-organizing into multicellular tissues, and important players in this process are cadherin receptors. Through the homophilic interactions of cadherins, cells adhere to one another. Cells can also dynamically change shapes or positions within tissue layers via cadherin-cytoskeleton interactions and become arranged into various architectures.
• Taking a Developmental Perspective on Systems Biology
  - Dev Cell 21(1):27-28 (2011)
  Developmental biologists understand how different cells contribute to organ function and how cellular components work together to produce a phenotype. These insights need to be more widely applied to systems biology. Another challenge is to incorporate real-time imaging and develop computational approaches to model biological phenomena in four dimensions.
• Drosophila as a Model for Interorgan Communication: Lessons from Studies on Energy Homeostasis
  - Dev Cell 21(1):29-31 (2011)
  Current studies of physiological communication between Drosophila organs are beginning to address the fundamental problem of how nutrients regulate organismal growth, stem cell behavior, immunity, and aging. Advances in the Drosophila genetic tool kit will allow the design of genetic screens to systematically identify factors involved in organ communication.
• Protein Evolution in Cell and Tissue Development: Going Beyond Sequence and Transcriptional Analysis
  - Dev Cell 21(1):32-34 (2011)
  Studies of animal evolution often focus on sequence and transcriptional analysis, based on an assumption that the evolution of development is driven by changes in gene expression. We argue that biochemical and cell biological approaches are also required, because sequence-conserved proteins can have different biochemical, cellular, and developmental properties.
• A Hitchhiker's Guide to Mechanobiology
  - Dev Cell 21(1):35-47 (2011)
  More than a century ago, it was proposed that mechanical forces could drive tissue formation. However, only recently with the advent of enabling biophysical and molecular technologies are we beginning to understand how individual cells transduce mechanical force into biochemical signals. In turn, this knowledge of mechanotransduction at the cellular level is beginning to clarify the role of mechanics in patterning processes during embryonic development. In this perspective, we will discuss current mechanotransduction paradigms, along with the technologies that have shaped the field of mechanobiology.
• Forward and Reverse Genetic Approaches for the Analysis of Vertebrate Development in the Zebrafish
  - Dev Cell 21(1):48-64 (2011)
  The development of facile forward and reverse genetic approaches has propelled the deconvolution of gene function in biology. While the origins of these techniques reside in the study of single-cell or invertebrate organisms, in many cases these approaches have been applied to vertebrate model systems to gain powerful insights into gene function during embryonic development. This perspective provides a summary of the major forward and reverse genetic approaches that have contributed to the study of vertebrate gene function in zebrafish, which has become an established model for the study of animal development.
• Developmental Genetics and New Sequencing Technologies: The Rise of Nonmodel Organisms
  - Dev Cell 21(1):65-76 (2011)
  Much of developmental biology in the past decades has been driven by forward genetic studies in a few model organisms. We review recent work with relatives of these species, motivated by a desire to understand the evolutionary and ecological context for morphological innovation. Unfortunately, despite a number of shining examples, progress in nonmodel systems has often been slow. The current revolution in DNA sequencing has, however, enormous potential in extending the reach of genetics. We discuss how developmental biology will benefit from these advances, particularly by increasing the universe of study species.
• The ESCRT Pathway
  - Dev Cell 21(1):77-91 (2011)
  Multivesicular bodies (MVBs) deliver cargo destined for degradation to the vacuole or lysosome. The ESCRT (endosomal sorting complex required for transport) pathway is a key mediator of MVB biogenesis, but it also plays critical roles in retroviral budding and cytokinetic abscission. Despite these diverse roles, the ESCRT pathway can be simply seen as a cargo-recognition and membrane-sculpting machine viewable from three distinct perspectives: (1) the ESCRT proteins themselves, (2) the cargo they sort, and (3) the membrane they deform. Here, we review ESCRT function from these perspectives and discuss how ESCRTs may drive vesicle budding.
• Mitochondria in Apoptosis: Bcl-2 Family Members and Mitochondrial Dynamics
  - Dev Cell 21(1):92-101 (2011)
  Mitochondria participate in apoptosis through a range of mechanisms that vary between vertebrates and invertebrates. In vertebrates, they release intermembrane space proteins, such as cytochrome c, to promote caspase activation in the cytosol. This process is the result of the loss of integrity of the outer mitochondrial membrane caused by proapoptotic members of the Bcl-2 family. This event is always accompanied by a fissioning of the organelle. Fission of mitochondria has also been reported to participate in apoptosis in Drosophila and Caenorhabditis elegans. However, in these organisms, mitochondrial membrane permeabilization does not occur and the mechanism by which mitochondrial dynamics participates in cell death remains elusive.
• Mitotic Spindle Orientation in Asymmetric and Symmetric Cell Divisions during Animal Development
  - Dev Cell 21(1):102-119 (2011)
  The orientation of the mitotic spindle has been proposed to control cell fate choices, tissue architecture, and tissue morphogenesis. Here, we review the mechanisms regulating the orientation of the axis of division and cell fate choices in classical models of asymmetric cell division. We then discuss the mechanisms of mitotic spindle orientation in symmetric cell divisions and its possible implications in tissue morphogenesis. Many recent studies show that future advances in the field of mitotic spindle orientation will arise from combinations of physical perturbation and modeling with classical genetics and developmental biology approaches.
• Planar Cell Polarity: Coordinating Morphogenetic Cell Behaviors with Embryonic Polarity
  - Dev Cell 21(1):120-133 (2011)
  Planar cell polarization entails establishment of cellular asymmetries within the tissue plane. An evolutionarily conserved planar cell polarity (PCP) signaling system employs intra- and intercellular feedback interactions between its core components, including Frizzled, Van Gogh, Flamingo, Prickle, and Dishevelled, to establish their characteristic asymmetric intracellular distributions and coordinate planar polarity of cell populations. By translating global patterning information into asymmetries of cell membranes and intracellular organelles, PCP signaling coordinates morphogenetic behaviors of individual cells and cell populations with the embryonic polarity. In vertebrates, by polarizing cilia in the node/Kupffer's vesicle, PCP signaling links the anteroposterior to left-right embryonic polarity.
• Notch Ligand Ubiquitylation: What Is It Good For?
  - Dev Cell 21(1):134-144 (2011)
  In the first volume of Developmental Cell, it was reported that the classic Drosophila neurogenic gene neuralized encodes a ubiquitin ligase that monoubiquitylates the Notch ligand Delta, thus promoting Delta endocytosis. A requirement for ligand internalization by the signal-sending cell, although counterintuitive, remains to date a feature unique to Notch signaling. Ten years and many ubiquitin ligases later, we discuss sequels to these three papers with an eye toward reviewing the development of ideas for how ligand ubiquitylation and endocytosis propel Notch signaling.
• Extracellular Movement of Signaling Molecules
  - Dev Cell 21(1):145-158 (2011)
  Extracellular signaling molecules have crucial roles in development and homeostasis, and their incorrect deployment can lead to developmental defects and disease states. Signaling molecules are released from sending cells, travel to target cells, and act over length scales of several orders of magnitude, from morphogen-mediated patterning of small developmental fields to hormonal signaling throughout the organism. We discuss how signals are modified and assembled for transport, which routes they take to reach their targets, and how their range is affected by mobility and stability.
• Drosophila Stem Cell Niches: A Decade of Discovery Suggests a Unified View of Stem Cell Regulation
  - Dev Cell 21(1):159-171 (2011)
  The past decade of research on Drosophila stem cells and niches has provided key insights. Fly stem cells do not occupy a special "state" based on novel "stem cell genes" but resemble transiently arrested tissue progenitors. Moreover, individual stem cells and downstream progenitors are highly dynamic and dispensable, not tissue bulwarks. Niches, rather than fixed cell lineages, ensure tissue health by holding stem cells and repressing cell differentiation inside, but not outside. We review the five best-understood adult Drosophila stem cells and argue that the fundamental biology of stem cells and niches is conserved between Drosophila and mice.
• The Cellular Basis for Animal Regeneration
  - Dev Cell 21(1):172-185 (2011)
  The ability of animals to regenerate missing parts is a dramatic and poorly understood aspect of biology. The sources of new cells for these regenerative phenomena have been sought for decades. Recent advances involving cell fate tracking in complex tissues have shed new light on the cellular underpinnings of regeneration in Hydra, planarians, zebrafish, Xenopus, and Axolotl. Planarians accomplish regeneration with use of adult pluripotent stem cells, whereas several vertebrates utilize a collection of lineage-restricted progenitors from different tissues. Together, an array of cellular strategies—from pluripotent stem cells to tissue-specific stem cells and dedifferentiation—are utilized for regeneration.