http://precedings.nature.com/tags/Epigenetics Recently posted documents tagged with 'Epigenetics' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/2782/version/1 Due to the increasing popularity of Jatropha curcas as a feedstock for biodiesel, generating non-toxic and high yielding varieties of the plant requires genotypic characterization towards identifying breeding lines. There is little information on the phylogenetic relationships between its global accessions and species. Assessing genetic variation by RAPD, AFLP and combinatorial tubulin based polymorphism (cTBP) in 38 J. curcas accessions from 13 countries on 3 continents revealed narrow genetic diversity. However, 6 different species of Jatropha from India exhibited pronounced genetic diversity indicating possibilities of improving J. curcas by interspecific breeding. The relatively unexplored cTBP approach we used was a highly efficient and cost effective genotyping tool. Using such tools towards breeding J. curcas for low phorbol ester (PE) content is highly desirable because of the co-carcinogenic nature of the PEs present in all the commercially relevant parts such as seeds, seed-cake and biodiesel. We report initial success in obtaining interspecific F1 and back cross (BC1) plants with low PE and improved agronomic traits.Further efforts will lead to generating varieties with targeted traits. Despite the limited genetic diversity within J. curcas accessions, appreciable variability was noticed in important phenotypic, physiological and biochemical traits such as seed size, water use efficiency and seed oil content respectively. This implicates fundamental epigenetic regulatory mechanisms and posits J. curcas as a unique system to study them. http://precedings.nature.com/documents/2782/version/1 Fri, 16 Jan 2009 14:16:37 UTC Narrow genetic and apparent phenetic diversity in Jatropha curcas: initial success with generating low phorbol ester interspecific hybrids hdl:10101/npre.2009.2782.1 2009-01-16 Ajay Kohli Nature Precedings 2009-01-16T14:16:37Z Manuscript Biotechnology Ecology Genetics & Genomics Earth & Environment Plant Biology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.1751.2 Early studies of molecular evolution revealed a correlation between genetic distance and time of species divergence. This observation provoked the molecular clock hypothesis and in turn the ‘Neutral Theory’, which however remains an incomplete explanation since it predicts a constant mutation rate per generation whereas empirical evidence suggests a constant rate per year. Data inconsistent with the molecular clock hypothesis have steadily accumulated in recent years that show no correlation between genetic distance and time of divergence. It has therefore become a challenge to find a testable idea that can reconcile the seemingly conflicting data sets. Here, an inverse relationship between genetic diversity and epigenetic complexity was deduced from a simple intuition in building complex systems. Genetic diversity, i.e., genetic distance or dissimilarity in DNA or protein sequences between individuals or species, is restricted by the complexity of epigenetic programs. This inverse relationship logically deduces the maximum genetic diversity (MGD) hypothesis, which suggests that macroevolution from simple to complex organisms involves a punctuational increase in epigenetic complexity that in turn causes a punctuational loss in genetic diversity. The hypothesis fully grants Neo-Darwinism to be what it really is (a theory of microevolution) and explains all the major facts of evolution. Importantly, it predicts the most remarkable result of molecular evolution, the genetic equidistance result, which originally provoked the molecular clock hypothesis. http://dx.doi.org/10.1038/npre.2009.1751.2 Thu, 15 Jan 2009 15:25:06 UTC Inverse relationship between genetic diversity and epigenetic complexity doi:10.1038/npre.2009.1751.2 2009-01-15 Shi Huang Nature Precedings 2009-01-15T15:25:06Z Manuscript Genetics & Genomics Bioinformatics Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1845/version/1 The green fluorescent protein (GFP) of jellyfish (Aequorea victoria) has significant advantages over other reporter genes, because expression can be detected in living cells without any substrates. Recently, epigenetic phenomena are important to consider in plant biotechnology experiments for elucidate unknown mechanism. Therefore, soybean immature cotyledons were generated embryogenesis cells and engineered with two different gene constructs (pHV and pHVS) using gene gun method. Both constructs contain a gene conferring resistance to hygromycin (hpt) as a selective marker and a modified glycinin (11S globulin) gene (V3-1) as a target. However, sGFP(S65T) as a reporter gene was used only in pHVS as a reporter gene for study the relation between using sGFP(S65T) and gene silencing phenomena. Fluorescence microscopic was used for screening after the selection of hygromycin, identified clearly the expression of sGFP(S65T) in the transformed soybean embryos bombarded with the pHVS construct. Protein analysis was used to detect gene expression overall seeds using SDS-PAGE. Percentage of gene down regulation was highly in pHV construct compared with pHVS. Thus, sGFP(S65T) as a reporter gene in vector system may be play useful role for transgenic evaluation and avoid gene silencing in plants for the benefit of plant transformation system. http://precedings.nature.com/documents/1845/version/1 Wed, 30 Apr 2008 12:48:13 UTC Green Fluorescent Protein (GFP) in Vector Systems Played Sense Role of Epigenetic in Plants hdl:10101/npre.2008.1845.1 2008-04-30 Hany A. El-Shemy Nature Precedings 2008-04-30T12:48:13Z Manuscript Biotechnology Molecular Cell Biology Plant Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1751/version/1 Early studies of molecular evolution revealed a correlation between genetic distance and time of species divergence. This observation provoked the molecular clock hypothesis and in turn the ‘Neutral Theory’, which however remains an incomplete explanation since it predicts a constant mutation rate per generation whereas empirical evidence suggests a constant rate per year. Data inconsistent with the molecular clock hypothesis have steadily accumulated in recent years that show no correlation between genetic distance and time of divergence. It has therefore become a challenge to find a testable idea that can reconcile the seemingly conflicting data sets. Here, an inverse relationship between genetic diversity and epigenetic complexity was deduced from a simple intuition in building complex systems. Genetic diversity, i.e., genetic distance or dissimilarity in DNA or protein sequences between individuals or species, is restricted by the complexity of epigenetic programs. This inverse relationship logically deduces the maximum genetic diversity hypothesis, which suggests that macroevolution from simple to complex organisms involves a punctuational increase in epigenetic complexity that in turn causes a punctuational loss in genetic diversity. The hypothesis explains a diverse set of biological phenomena, including both for and against the correlation between genetic distance and time of divergence. http://precedings.nature.com/documents/1751/version/1 Wed, 02 Apr 2008 13:10:20 UTC Inverse relationship between genetic diversity and epigenetic complexity hdl:10101/npre.2008.1751.1 2008-04-02 Shi Huang Nature Precedings 2008-04-02T13:10:20Z Manuscript Ecology Genetics & Genomics Bioinformatics http://creativecommons.org/licenses/by/3.0/