Reviews & Analysis

Chromosomal position effects influence the transcription of exogenously introduced transgenes. A new study identifies molecular tools that exploit these properties to fine-tune transgenic gene expression through the use of site-specific integration and the gypsy insulator element.

Two studies report the application of high-throughput sequencing technologies to discover infectious agents associated with diseased human tissues. These findings herald a breakthrough in the field of pathogen discovery.

The HIV viral lifecycle includes infection of a host cell, followed by a critical decision between latency and lysis. A new study suggests that positive feedback in the HIV-1 promoter, involving Tat protein and gene expression, has a role in this critical choice of fate.

Rare syndromes offer unique opportunities to gain insight into central physiological processes. By deciphering the genetic basis of two rare inherited diseases, two studies identify a key role for P2Y5, a G protein–coupled receptor, in hair follicle development.

A new mapping study identifies a natural protein variant influencing oil content and composition in maize seeds. This example illustrates the power of exploiting natural variation to improve crop yields and address current breeding challenges.

During meiosis, crossovers are regulated such that each pair of chromosomes has at least one crossover and multiple crossovers are evenly spaced. A new study leads to surprising insights regarding the timing of crossover regulation through the analysis of two genes involved in synaptonemal complex elongation.

Cranial neural crest cell migration is a prerequisite for normal craniofacial morphogenesis in animals. A new study shows that the movement of a specific subset of cranial neural crest cells is exquisitely sensitive to concentrations of a microRNA that targets platelet-derived growth factor receptor alpha mRNA.

Plasma lipoprotein concentrations are associated with risk of coronary artery disease, a leading cause of mortality and morbidity worldwide. Three new genome-wide association studies of thousands of individuals now identify seven genes or loci contributing to lipid concentrations and confirm a number of previously reported associations.

Many organisms have an amazing capacity to adapt to conditions of low oxygen, but the cellular mechanisms of this are poorly understood. A new study in mice has unveiled a molecular trigger that initiates a cascade of events to reprogram cellular oxygen requirements.

Rapid changes in mitochondrial DNA allele frequency between generations have been explained by an 'mtDNA bottleneck' in the germ line, and it has recently been proposed that mtDNA aggregates, or nucleoids, drive such a bottleneck. Now, a new study finds a sharp reduction in mtDNA content in the germ line and suggests that such reduction alone may account for the bottleneck effect.

The discovery of new risk variants for systemic lupus erythematosis (SLE), particularly around lymphocyte signaling pathways and integrins involved in clearing complement, provides fresh insights into this common human autoimmune disease. Understanding the role of the variants in disease pathophysiology and translating these findings into new therapies present major and urgent challenges to medical scientists.

Aberrant meiotic recombination can result in disease-causing chromosome microdeletions or microduplications. A new study of several disease-associated recombination hot spots in male germ cells shows that some genomic rearrangements, particularly microduplications, are significantly underdiagnosed.

Breast tumors with deficiency in DNA double-strand break repair might be expected to show aneuploidy. A new study shows that microdeletions in PTEN, resulting in complete loss of PTEN protein, are signature lesions in these cancers, particularly those arising in BRCA1-mutation carriers.