Reviews & Analysis

Non-invasive techniques for prenatal diagnosis are extremely advantageous in terms of both safety and cost. The discovery of fetal nucleic acids in the maternal plasma has led to the development of many non-invasive tests.

Despite the key role of recombination in meiosis, increasing evidence indicates substantial variation in recombination rates among humans, and between humans and other mammals. Understanding the forces that shape this variation will require a combination of evolutionary and molecular perspectives.

Both genetic and physiological studies are contributing to our understanding of insect body size, a trait that affects fitness in many ways and is therefore subject to intense selection. Many of the genes that determine body size in insects have similar roles in mammals.

Using cancer as an example of complex disease, the authors revisit the evidence for the hypothesis that human diseases result from interactions between genetic variants and the environment.

Intense investigation of the laminopathies has revised the traditional structural view of the nuclear lamina, highlighting crucial roles in processes including gene regulation and differentiation. This research has also led to a range of promising therapies for these rare diseases.

DNA signature tags, also known as molecular barcodes, were first developed in bacteria to facilitate functional screens by identifying mutants in mixed populations. Adaptations and refinements of this technology have yielded a wealth of information on a broad range of biological processes.

Combined with advances in immunology, genetic studies in human populations are revealing the diverse alterations in adaptive immunity that underlie autoimmune diseases. Recent studies have also highlighted an unexpected contribution of the innate immune system to these complex diseases.

Misleading views of embryology led to the marginalization of this field in the first half of the twentieth century. Gavin de Beer was partly responsible for introducing a genetic perspective to evo–devo, and anticipated continuing problems for molecular genetics.

Studies of regenerative biology have been hampered by a lack of tools for testing gene function in traditional model species. Recent advances have overcome this problem, leading to new insights into both basic regenerative biology and its biomedical potential.

The ability to provide information about variants in genes is crucial to genome-wide association studies. This article argues that the currently available marker sets are unlikely to provide adequate coverage of genic variants, and suggests how this problem could be overcome.

The recently emerged field of genetic analysis of global gene expression has shed light on the architecture of quantitative traits, transcriptional regulation and regulatory variation. It has provided a way of connecting DNA sequence variation with phenotypic variation.

The sonic hedgehog signalling molecule controls development at many stages and by different mechanisms. This article uses it to exemplify the fundamental mechanisms by which developmental growth and patterning are regulated in both vertebrates and invertebrates.

Complex physiological inputs and environmental influences have made mapping genetic determinants of hypertension susceptibility particularly challenging. Refining results from previous studies in both rats and humans, combined with new genome-wide approaches, is set to accelerate progress in this area.

Genomic techniques have pervaded studies of speciation genetics. Although they might not have led to changes in the prevailing hypotheses, the accelerated pace of data collection and compilation should help us to understand the relative frequency and importance of the different processes that cause speciation.

The concept of relatedness is central to many fields, from human linkage analysis to forensics to animal and plant breeding. This review covers the statistical framework for studying relatedness, its applications and the challenges that the field faces.

Gene–environment interactions are key contributors to complex disease, but are hard to dissect in commonly used case–control designs. This article argues that large-scale prospective cohort studies, several of which are planned or under way, provide an essential alternative strategy.

Transformation-associated recombination (TAR) cloning usesin vivorecombination in yeast to isolate large chromosomal segments from complex genomes. Although the principles of TAR cloning date back to the 1990s, recent modifications have opened up promising new applications of this technology.

Identifying polymorphisms that are overrepresented in disease cases versus controls would seem to be a straightforward process, but genetic association studies are notoriously riddled with complex analysis problems. This article outlines these statistical issues and provides some guidance to overcoming them.

Several models have been proposed to explain the spreading of heterochromatin, including looping, sliding and oozing. A review of studies from diverse model eukaryotes allows the authors to evaluate the existing models and leads them to propose a common, ancestral mechanism for spreading.

The vast increase in the amount of molecular genetic data that are being generated, and the scale of their complexity, demand ever more sophisticated statistical analysis methods — this article surveys and compares these approaches, and the growing reliance on computational methodologies.