Hot off the presses! Aug 01 Trends Genet

The Aug 01 issue of the Trends Genet is now up on Pubget (About Trends Genet): if you're at a subscribing institution, just click the link in the latest link at the home page. (Note you'll only be able to get all the PDFs in the issue if your institution subscribes to Pubget.)

Latest Articles Include:

• Editorial Board
  - Trends Genet 27(8):i (2011)
  
• Biogenesis and function of nuclear bodies
  - Trends Genet 27(8):295-306 (2011)
  Nuclear bodies including nucleoli, Cajal bodies, nuclear speckles, Polycomb bodies, and paraspeckles are membraneless subnuclear organelles. They are present at steady-state and dynamically respond to basic physiological processes as well as to various forms of stress, altered metabolic conditions and alterations in cellular signaling. The formation of a specific nuclear body has been suggested to follow a stochastic or ordered assembly model. In addition, a seeding mechanism has been proposed to assemble, maintain, and regulate particular nuclear bodies. In coordination with noncoding RNAs, chromatin modifiers and other machineries, various nuclear bodies have been shown to sequester and modify proteins, process RNAs and assemble ribonucleoprotein complexes, as well as epigenetically regulate gene expression. Understanding the functional relationships between the 3D organization of the genome and nuclear bodies is essential to fully uncover the regulation of gene expr! ession and its implications for human disease.
• Centrosomes and cilia in human disease
  - Trends Genet 27(8):307-315 (2011)
  Centrioles are microtubule-derived structures that are essential for the formation of centrosomes, cilia and flagella. The centrosome is the major microtubule organiser in animal cells, participating in a variety of processes, from cell polarisation to cell division, whereas cilia and flagella contribute to several mechanisms in eukaryotic cells, from motility to sensing. Although it was suggested more than a century ago that these microtubule-derived structures are involved in human disease, the molecular bases of this association have only recently been discovered. Surprisingly, there is very little overlap between the genes affected in the different diseases, suggesting that there are tissue-specific requirements for these microtubule-derived structures. Knowledge of these requirements and disease mechanisms has opened new avenues for therapeutical strategies. Here, we give an overview of recent developments in this field, focusing on cancer, diseases of brain devel! opment and ciliopathies.
• Regulatory mechanisms and networks couple the different phases of gene expression
  - Trends Genet 27(8):316-322 (2011)
  Gene expression comprises multiple stages, from transcription to protein degradation. Although much is known about the regulation of each stage separately, an understanding of the regulatory coupling between the different stages is only beginning to emerge. For example, there is a clear crosstalk between translation and transcription, and the localization and stability of an mRNA in the cytoplasm could already be determined during transcription in the nucleus. We review a diversity of mechanisms discovered in recent years that couple the different stages of gene expression. We then speculate on the functional and evolutionary significance of this coupling and suggest certain systems-level functionalities that might be optimized via the various coupling modes. In particular, we hypothesize that coupling is often an economic strategy that allows biological systems to respond robustly and precisely to genetic and environmental perturbations.
• Molecular mechanisms of epistasis within and between genes
  - Trends Genet 27(8):323-331 (2011)
  'Disease-causing' mutations do not cause disease in all individuals. One possible important reason for this is that the outcome of a mutation can depend upon other genetic variants in a genome. These epistatic interactions between mutations occur both within and between molecules, and studies in model organisms show that they are extremely prevalent. However, epistatic interactions are still poorly understood at the molecular level, and consequently difficult to predict de novo. Here I provide an overview of our current understanding of the molecular mechanisms that can cause epistasis, and areas where more research is needed. A more complete understanding of epistasis will be vital for making accurate predictions about the phenotypes of individuals.
• The impact of endosymbionts on the evolution of host sex-determination mechanisms
  - Trends Genet 27(8):332-341 (2011)
  The past years have revealed that inherited bacterial endosymbionts are important sources of evolutionary novelty for their eukaryotic hosts. In this review we discuss a fundamental biological process of eukaryotes influenced by bacterial endosymbionts: the mechanisms of sex determination. Because they are maternally inherited, several endosymbionts of arthropods, known as reproductive parasites, have developed strategies to convert non-transmitting male hosts into transmitting females through feminization of genetic males and parthenogenesis induction. Recent investigations have also highlighted that endosymbionts can impact upon host sex determination more subtly through genetic conflicts, resulting in selection of host nuclear genes resisting endosymbiont effects. Paradoxically, it is because of their selfish nature that reproductive parasites are such powerful agents of evolutionary change in their host sex-determination mechanisms. They might therefore represent e! xcellent models for studying transitions between sex-determining systems and, more generally, the evolution of sex-determination mechanisms in eukaryotes.