Hot off the presses! Oct 01 TRENDS GENET

The Oct 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 26(10):i (2010)
  
• Maintenance of duplicate genes and their functional redundancy by reduced expression
  Qian W Liao BY Chang AY Zhang J - TRENDS GENET 26(10):425-430 (2010)
  Although evolutionary theories predict functional divergence between duplicate genes, many old duplicates still maintain a high degree of functional similarity and are synthetically lethal or sick, an observation that has puzzled many geneticists. We propose that expression reduction, a special type of subfunctionalization, facilitates the retention of duplicates and the conservation of their ancestral functions. Consistent with this hypothesis, gene expression data from both yeasts and mammals show a substantial decrease in the level of gene expression after duplication. Whereas the majority of the expression reductions are likely to be neutral, some are apparently beneficial to rebalancing gene dosage after duplication.
• Mimivirus: the emerging paradox of quasi-autonomous viruses
  Claverie JM Abergel C - TRENDS GENET 26(10):431-437 (2010)
  What is a virus? Are viruses alive? Should they be classified among microorganisms? One would expect these simple questions to have been settled a century after the discovery of the first viral disease. For years, modern virology successfully unravelled the huge diversity of viruses in terms of genetic material, replication mechanism, pathogenicity, host infection, and more recently particle structure, planet-wide distribution and ecological significance. Yet, little progress was made in understanding their evolutionary origin(s), as well as the fundamental nature of their relationship with the cellular world. Thanks to the recent studies on Mimivirus and other large DNA viruses, we are now entering a new era where the most basic concepts about viruses are revisited, including their true nature, how fundamentally different they are from cellular microorganisms, and how essential they might have been in the major innovations that punctuated the evolution of life.
• Towards a complete resolution of the genetic architecture of disease
  Singleton AB Hardy J Traynor BJ Houlden H - TRENDS GENET 26(10):438-442 (2010)
  After years of linear gains in the genetic dissection of human disease we are now in a period of exponential discovery. This is particularly apparent for complex disease. Genome-wide association studies (GWAS) have provided myriad associations between common variability and disease, and have shown that common genetic variability is unlikely to explain the entire genetic predisposition to disease. Here we detail how one can expand on this success and systematically identify genetic risks that lead or predispose to disease using next-generation sequencing. Geneticists have had for many years a protocol to identify Mendelian disease. A similar set of tools is now available for the identification of rare moderate-risk loci and common low-risk variants. Whereas major challenges undoubtedly remain, particularly regarding data handling and the functional classification of variants, we suggest that these will be largely practical and not conceptual.
• Crosstalk between genetic and epigenetic information through cytosine deamination
  Chahwan R Wontakal SN Roa S - TRENDS GENET 26(10):443-448 (2010)
  Decades of work have elucidated the existence of two forms of heritable information, namely genetic and epigenetic, which are collectively referred to as the 'dual inheritance'. The underlying mechanisms behind these two modes of inheritance have so far remained distinct. Cytosine deaminases, such as activation-induced cytidine deaminase (AID) and other members of the APOBEC family, have been implicated both in genetic variation of somatic cells and in epigenetic remodeling of germ and pluripotent cells. We hereby synthesize these seemingly dissociated functions into one coherent model, and further suggest that cytosine deaminases, particularly AID, might have a broader influence by modulating epigenetic information in somatic or cancer cells, as well as by triggering genetic variation in germ and pluripotent cells through mutation followed by natural selection. We therefore propose that the AID/APOBEC family of deaminases are likely to have acted as drivers throug! hout vertebrate evolution.
• Secondary metabolic gene clusters: evolutionary toolkits for chemical innovation
  Osbourn A - TRENDS GENET 26(10):449-457 (2010)
  Microbes and plants produce a huge array of secondary metabolites that have important ecological functions. These molecules have long been exploited in medicine as antibiotics, anticancer and anti-infective agents and for a wide range of other applications. Gene clusters for secondary metabolic pathways are common in bacteria and filamentous fungi, and examples have now been discovered in plants. Here, current knowledge of gene clusters across the kingdoms is evaluated with the aim of trying to understand the rules behind cluster existence and evolution. Such knowledge will be crucial in learning how to activate the enormous number of 'silent' gene clusters being revealed by whole-genome sequencing and hence in making available a wealth of novel compounds for evaluation as drug leads and other bioactives. It could also facilitate the development of crop plants with enhanced pest or disease resistance, improved nutritional qualities and/or elevated levels of high-va! lue products.