Reviews & Analysis

Drosophila melanogasterhaemocytes operate as the first line of defence against invading microorganisms during larval and adult life. However, in the developing embryo, haemocytes undergo complex migrations and carry out several non-immune functions that are crucial for successful development.

In vitroembryonic stem (ES)-cell studies present a unique set of tools to understand embryonic development; however, these studies face many challenges. What are the current and future strategies for the exploitation of ES cells in developmental cell biology?

Recent large-scale functional genomics and proteomics analyses have revealed novel molecules that are involved in regulating centrosome function and biogenesis. Other studies indicate that certain molecules that inhibit the re-replication of DNA might also inhibit centriole reduplication, thereby linking chromosome and centrosome cycles.

Many RNA-binding proteins have a modular structure and are composed of multiple repeats of a few small RNA-binding domains. By arranging the domains in various ways, these proteins can carry out their diverse biological roles in an RNA-specific manner.

Common regulatory enzymes affect the function of the class O of forkhead box transcription factors (FoxOs) and p53 in an opposite manner. Recent findings indicate that this shared yet opposing regulatory network between FoxOs and p53 may underlie a 'trade-off' between disease and lifespan.

Understanding the mechanisms of plant development requires the ability to monitor the spatial and temporal control of gene and protein activity as well as cell behaviours in real timein vivo. The dynamic properties of plant processes can now be captured through the simultaneous use of live imaging and transient perturbation technologies.

During the cell cycle, organelles such as the endoplasmic reticulum and Golgi apparatus must be replicated and partitioned into the daughter cells. Different mechanisms have evolved in yeasts, protozoa and metazoans to solve this problem.

The growth of the blood and lymphatic systems provides an excellent example for the tight coordination of diverse cellular processes during tissue morphogenesis. Elucidation of the molecular players and their roles in the development of endothelial networks will also provide insights into human disease.

Recent data on the genetic and molecular basis of progeroid syndromes have shed light onto the nuclear metabolic defects that might accelerate ageing. What are the mechanistic features of progeroid syndromes? And how can these findings help us understand normal ageing?

The endosomal sorting complex required for transport (ESCRT) machinery facilitates the sorting of proteins that are destined for lysosomal degradation into multivesicular bodies. Recent structural and functional studies provide new insights into the regulation of this machinery and the biogenesis of multivesicular bodies.

Intriguing parallels in the organization of stem-cell niches have been revealed between plants and animals. Recent evidence indicates that stem cells in multicellular organisms can be specified by kingdom-specific patterning mechanisms that connect to a related core of epigenetic stem-cell factors.

Transport of soluble proteins into the nucleus depends either on binding a protein-transport complex or on being small enough to diffuse in. Recent studies indicate that the delivery of integral membrane proteins into the inner nuclear membrane is governed by the same rules.

The spindle-assembly checkpoint is a safety device that monitors the attachment of spindle microtubules to kinetochores and ensures the fidelity of chromosome segregation in mitosis. Molecular studies are finally starting to reveal the mechanisms of checkpoint activation and inactivation.

Histone acetyltransferases (HATs) are highly diverse multiprotein complexes that carry out diverse functions, ranging from repairing regions of DNA damage to maintaining overall genomic integrity. HATs are regulated by associated factors and by the dynamic interplay with existing histone modifications.

p53 is best known as a tumour suppressor, although recent studies have challenged the view that this is its only role. Instead, p53 has important functions in organismal development, and might contribute to a number of diseases other than cancer.

The apoptosome is a cytosolic signalling platform that integrates intracellular death signals. The formation of the apoptosome and the activation of its effector, caspase-9, reveal a sophisticated mechanism that might be more common than was initially thought.

Transformations from one tissue type to another are an established set of phenomena that can be explained by the principles of developmental biology. So, can we deliberately reprogramme cells from one tissue type to another to generate new therapies for human diseases?

Although netrins were identified as migrational cues in the developing central nervous system (CNS), recent work has highlighted previously unrecognized functions of netrins outside the CNS. Netrins regulate diverse processes, such as cell adhesion, motility, proliferation, differentiation and, ultimately, cell survival.

Recent studies have identified some of the factors that are involved in WNT secretion and have brought the focus of WNT research to the issue of how WNT proteins are secreted. What are the possible mechanisms that underlie this process?

Methylation of histone residues is important for the regulation of gene transcription, epigenetic inheritance and cell fate. Histone methylation was long considered a stable modification, but the recent identification of a histone deiminase and histone demethylases has shown that histone methylation can be dynamically regulated.