Evolution of light-harvesting complex proteins from Chl c-containing algae

<p>Abstract</p> <p>Background</p> <p>Light harvesting complex (LHC) proteins function in photosynthesis by binding chlorophyll (Chl) and carotenoid molecules that absorb light and transfer the energy to the reaction center Chl of the photosystem. Most research has focused on LHCs of plants and chlorophytes that bind Chl <it>a </it>and <it>b </it>and extensive work on these proteins has uncovered a diversity of biochemical functions, expression patterns and amino acid sequences. We focus here on a less-studied family of LHCs that typically bind Chl <it>a </it>and <it>c</it>, and that are widely distributed in Chl <it>c</it>-containing and other algae. Previous phylogenetic analyses of these proteins suggested that individual algal lineages possess proteins from one or two subfamilies, and that most subfamilies are characteristic of a particular algal lineage, but genome-scale datasets had revealed that some species have multiple different forms of the gene. Such observations also suggested that there might have been an important influence of endosymbiosis in the evolution of LHCs.</p> <p>Results</p> <p>We reconstruct a phylogeny of LHCs from Chl <it>c</it>-containing algae and related lineages using data from recent sequencing projects to give ~10-fold larger taxon sampling than previous studies. The phylogeny indicates that individual taxa possess proteins from multiple LHC subfamilies and that several LHC subfamilies are found in distantly related algal lineages. This phylogenetic pattern implies functional differentiation of the gene families, a hypothesis that is consistent with data on gene expression, carotenoid binding and physical associations with other LHCs. In all probability LHCs have undergone a complex history of evolution of function, gene transfer, and lineage-specific diversification.</p> <p>Conclusion</p> <p>The analysis provides a strikingly different picture of LHC diversity than previous analyses of LHC evolution. Individual algal lineages possess proteins from multiple LHC subfamilies. Evolutionary relationships showed support for the hypothesized origin of Chl <it>c </it>plastids. This work also allows recent experimental findings about molecular function to be understood in a broader phylogenetic context.</p

Shape evolutions in fission dynamics within time-dependent Hartree-Fock approach

We studied the nuclear shape evolutions in fission process of 240Pu by the time-dependent Hartree- Fock approach with various Skyrme forces. Calculations are performed for the later phase of the fission with large initial deformations towards the scission. We show that calculations with Skyrme forces with large surface energies and large symmetry energies can have extremely long fission evolution time. The symmetry energy plays a role in the evolution of neutron-rich necks. In addition, we also demonstrated the shape oscillations of fission fragments after the fission. We see that particularly the heavy near-spherical fragments have remarkable octupole oscillations

Gene expression profile of cerebrospinal fluid mononuclear cells in oligoclonal band positive and oligoclonal band negative multiple sclerosis patients at early stage of disease

Different blood and CSF T and B lymphocyte subsets are thought to be involved in multiple sclerosis (MS) pathogenesis. Microarray technology provides a tool for large-scale analysis of gene expression programs. Microarray analysis of CSF inflammatory cells may improve our understanding of the unique immunological context within the CNS compartment