Reviews & Analysis

How did the complex regulatory networks that control eukaryotic gene expression evolve? This article explores evidence that transposable elements played an important part by providing thecis and transcomponents of these networks.

Established during embryogenesis, vertebrate segmentation is most conspicuous at the level of the periodic arrangement of vertebrae in the spine. Since the identification of the segmentation clock, which is a travelling oscillator, the generation of segmental pattern in the presomitic mesoderm has been a particular focus of attention.

Newly specified hepatic and pancreatic progenitors, which originate from common endodermal domains, are able to reverse their course and develop into gut progenitors. Understanding what underlies such programming reversal and intrinsic regenerative capacities should illuminate the basis of cellular plasticity and facilitate targeted programming of stem cells.

Genome-wide association studies have led to an improved understanding of the genetic basis of common diseases. Following the first wave of such studies, this Review takes a critical look at progress so far and considers how future studies can be optimized.

The highly heterogeneous nature of autism has made this syndrome difficult to dissect genetically. Recent work has highlighted the importance ofde novoand inherited copy number variation as well as common genetic risk variants in defining potential biological mechanisms of disease.

Tight coordination of gene expression between the nucleus and genome-containing organelles (mitochondria and chloroplasts), and between organelles themselves, is essential to the survival of a eukaryotic cell. This article reviews our current understanding of the mechanisms behind this multidirectional signalling.

Comparative genomics is a promising approach for identifying functional components of genomes. However, many challenges remain, relating to the quality and quantity of sequence data, how sequences are aligned and, ultimately, how functional elements are recognized.

Microarray-based approaches are a fast, flexible and inexpensive alternative to genome sequencing for characterizing the genomes of many individuals within a species. This article reviews the advances that are making microarrays a viable choice for detecting all forms of genetic diversity.

It is conventionally thought that there is a simple relationship between viral mutation rates and polymerase fidelity. This article argues that the pattern of virus evolution is also shaped by other aspects of viral biology.

Heritability is one of the oldest parameters in genetics, but also one of the most misunderstood. The authors explore exactly what heritability means, the pitfalls to avoid when using it, and its continued relevance in the genomics era.

Symbiosis is an important source of evolutionary innovation. Genome sequencing and metagenomics have accelerated our understanding of the broad phylogenetic reach of this phenomenon, its complex and diverse nature, and the evolutionary paths followed by eukaryotic hosts and their prokaryotic symbionts.

A variety of forward and reverse genetics screening tools are available in maize. The rich natural allelic variation of this species is also being used to map the genes underlying biologically and agronomically important traits that are also relevant to other cereal crops.

In multicellular organisms, the identity of a cell is determined by its unique gene expression pattern, which is remembered and passed on to daughter cells by epigenetic mechanisms. Recent technical advances are enabling researchers to look at how epigenetic changes are coordinated on a genome-wide scale, thus giving rise to a new field of epigenomics.

Genomic instability encompasses a range of genetic alterations from point mutations to chromosome rearrangements. From the perspective ofcis and trans-acting elements, these authors provide a mechanistic perspective on the origin of genomic instability.

Toll-like receptors have important functions in immunity and development across the animal kingdom. An evolutionary analysis suggests that the analogous immune functions have arisen independently in vertebrates and invertebrates.

Theodor Boveri is best remembered for his chromosome theory of heredity. However, the contributions that he and his wife, Marcella O'Grady Boveri, made to the early days of genetics are greater than just this.

Genetic, biochemical, ultrastructural and physiological studies of mouse mutants have crucially advanced our understanding of the molecular mechanisms of hearing. A detailed picture is emerging of the protein complexes that are responsible for the growth and cohesion of the stereocilia bundle — a complex subcellular structure at the core of the auditory apparatus.

The epigenetic profile of germ cells undergoes several significant changes that are essential for post-fertilization development to occur. An emerging theme from recent studies is that epigenetic modifiers also have key roles in the development of germ cells themselves.

Rice is the first crop plant to have its genome sequenced. Because of the importance of rice for a significant proportion of the world's population, functionally characterizing rice genes is an economic as well as a scientific imperative.

MicroRNAs mediate post-translational regulation of gene expression in various organisms. Although it is clear that the specificity of their action is achieved by base-pair complementarity, the precise mechanism by which they repress translation has been controversial. Clear answers are only beginning to emerge.