When repair meets chromatin: First in series on chromatin dynamics

In eukaryotic cells, the inheritance of both the DNA sequence and its organization into chromatin is critical to maintain genome stability. This maintenance is challenged by DNA damage. To fully understand how the cell can tolerate genotoxic stress, it is necessary to integrate knowledge of the nature of DNA damage, its detection and its repair within the chromatin environment of a eukaryotic nucleus. The multiplicity of the DNA damage and repair processes, as well as the complex nature of chromatin, have made this issue difficult to tackle. Recent progress in each of these areas enables us to address, both at a molecular and a cellular level, the importance of inter-relationships between them. In this review we revisit the ‘access, repair, restore’ model, which was proposed to explain how the conserved process of nucleotide excision repair operates within chromatin. Recent studies have identified factors potentially involved in this process and permit refinement of the basic model. Drawing on this model, the chromatin alterations likely to be required during other processes of DNA damage repair, particularly double-strand break repair, are discussed and recently identified candidates that might perform such alterations are highlighted

Conservation planning in spatially and temporally dynamic marine environments

Pelagic ecosystems provide a significant and vital component of the ocean’s productivity and biodiversity. They are also heavily exploited and are currently the focus of numerous ecosystem-based management exercises. Over the past ten years there has been increasing enthusiasm for marine protected areas (MPAs) as a tool for pelagic conservation. However, there remains almost a complete absence of systematic conservation planning in the pelagic realm, both within exclusive economic zones and the high seas. Here we demonstrate the use of a decision support system to guide the implementation of MPAs that consider the physical and biological dynamics typical of the pelagic realm, and propose a method for integrative planning for pelagic and benthic conservation in the Southern Benguela ecosystem. Our approach was to maximize the representation of threatened species and key fisheries species within MPAs closed to fishing. In addition to representation, we consider MPA design to address the dynamics of the system using time series data of key oceanographic characteristics and abundance of small pelagic fish. We also discuss problems associated with offshore conservation, where the features of interest are ephemeral and dynamic. Our approach explicitly involves stakeholders and we incorporate socio-economic data into decision support tools