Volume 9 Issue 3, March 2008

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.

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.

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.

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.

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.

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.

The application of gene therapy to treat human disorders has made many advances in recent years, although many ethical challenges associated with this type of intervention remain unresolved. This Perspective describes the special challenges posed by research in this field.