Review Articles in 2008

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.

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.

Cell-cycle regulation is emerging as a crucial aspect of the ability of stem cells to self-renew. Genetic studies in mice have provided insights into the nature of this regulation, highlighting shared principles in embryonic and adult stem cells.

From the structure of DNA to epigenetic modifications, structural biology has contributed much to genetics. The benefits can also flow the other way — structural determination is benefiting from high-throughput genomic technologies.

Genome-wide approaches have extended our understanding of known coupling and coordination mechanisms among eukaryotic gene regulatory processes, and they are revealing previously unknown interconnectivities. These findings are providing new insights into how cells generate coordinated, flexible and sensitive gene-expression responses.

Accumulating evidence suggests that the regulated turnover of nucleosomes is key to the epigenetic regulation of eukaryotic gene expression. This insight has important implications for understanding the functional importance of histone modifications and the incorporation of histone variants into chromatin.

Although genome sequencing has become a routine task, genome annotation remains a complicated business. New computational methods, in combination with experimental methods, are bringing us closer to describing the ORF structure of every gene in every genome.

A detailed picture of the mechanism of homologous recombination has been gathered over the years, but deciphering how homologues get together in the first place has been far more elusive. The authors examine various scenarios for how this might occur.

The highly conserved Notch signalling pathway functions at several stages in heart development. The involvement of Notch in development and in congenital and adult cardiovascular disorders is being elucidated through the use of genetic and molecular analyses in animal models.