Volume 10 Issue 7, July 2009

Recent genome-wide studies have identified many common variants that are associated with non-syndromic obesity, providing new opportunities to explore its biological basis. Understanding the roles of epigenetics and of rare and copy number variants are important goals for the future.

This Review presents a quantitative framework for translating DNA sequences into transcriptional behaviours. Such a model, based on the binding affinity landscape of molecules to genomic sequences, can help to describe complex phenomena such as transcriptional noise and the evolution of transcriptional regulation.

Foci of transcriptional activity are observed in eukaryotic nuclei and have been called transcription factories. However, many uncertainties about their function and identity remain and the evidence can be conflicting, as the authors discuss in this Review.

How cell fate decisions are made is a fundamental question in developmental biology. Recent analyses of the first two fate decisions in mammalian embryogenesis illustrate the potential interplay of transcriptional circuits, epigenetic modification, cell position and polarity in lineage choice.

Mutations that arisede novoin the human germ line are rare, but they contribute significantly to disease. This Review discusses current methods of assessing mutation frequency and examines factors — from nucleotide context and gene function to parental sex and age — that influence mutation patterns.

Molecular genetic testing is increasingly being used in health care settings. The authors discuss the challenges faced by decision makers when weighing up the health benefits of testing, and its economic costs.

The mitochondrion and plastid are derived from bacterial endosymbionts that were transformed over time into organelles. Here the authors posit an explanation for how the eukaryotic hosts controlled the evolution of these organelles through the establishment of protein-sorting systems.