A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light ...A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light induced radical stress is a direct interaction of light with photoreceptors or a secondary mechanism within the pigment epithelium or choroid is in discussion. Among the molecular mechanisms involved are production of reactive oxygen species(ROS), secondary lipid peroxidation, protein oxidation and DNA-damage. The initial trigger to write this review was first a recent finding of our group that the photoreceptor outer segments produce great amounts of ROS and second the detection of ectopic enzymes of the respiratory chainlocalized there- in addition to the hitherto known ROS sources like the visual pigments with their intermediates and the photoreceptor mitochondria harbouring the respiratory chain.展开更多
RNA silencing is an evolutionarily conserved mechanism in eukaryotic organisms induced by double-stranded RNA(dsRNA)and plays an essential role in regulating gene expression and maintaining genome stability.RNA silenc...RNA silencing is an evolutionarily conserved mechanism in eukaryotic organisms induced by double-stranded RNA(dsRNA)and plays an essential role in regulating gene expression and maintaining genome stability.RNA silencing occurs at both posttranscriptional levels through sequence-specific RNA degradation or translational repression and at transcriptional levels through RNA-directed DNA methylation and/or hetero-chromatin formation.RNA silencing pathways have been relatively well characterized in plants and animals,and are now also being widely investigated in diverse fungi,some of which are important plant pathogens.This review focuses primarily on the current understanding of the dsRNA-mediated posttranscriptional gene silencing pro-cesses in fungi,but also discusses briefly the known gene silencing pathways that appear to be independent of the RNA silencing machineries.We review RNA silencing studies for a variety of fungi and highlight some of the mechanistic differences observed in different fungal organisms.As RNA silencing is being exploited as a technology in gene function studies in fungi as well as in engineering anti-fungal resistance in plants and animals,we also discuss the recent progress towards understanding dsRNA uptake in fungi.展开更多
文摘A number of studies have shown that oxidative stress can be harmful for the retina. The real causal circumstances that lead to degenerative diseases like age related macular degeneration remain obscure. Whether light induced radical stress is a direct interaction of light with photoreceptors or a secondary mechanism within the pigment epithelium or choroid is in discussion. Among the molecular mechanisms involved are production of reactive oxygen species(ROS), secondary lipid peroxidation, protein oxidation and DNA-damage. The initial trigger to write this review was first a recent finding of our group that the photoreceptor outer segments produce great amounts of ROS and second the detection of ectopic enzymes of the respiratory chainlocalized there- in addition to the hitherto known ROS sources like the visual pigments with their intermediates and the photoreceptor mitochondria harbouring the respiratory chain.
文摘RNA silencing is an evolutionarily conserved mechanism in eukaryotic organisms induced by double-stranded RNA(dsRNA)and plays an essential role in regulating gene expression and maintaining genome stability.RNA silencing occurs at both posttranscriptional levels through sequence-specific RNA degradation or translational repression and at transcriptional levels through RNA-directed DNA methylation and/or hetero-chromatin formation.RNA silencing pathways have been relatively well characterized in plants and animals,and are now also being widely investigated in diverse fungi,some of which are important plant pathogens.This review focuses primarily on the current understanding of the dsRNA-mediated posttranscriptional gene silencing pro-cesses in fungi,but also discusses briefly the known gene silencing pathways that appear to be independent of the RNA silencing machineries.We review RNA silencing studies for a variety of fungi and highlight some of the mechanistic differences observed in different fungal organisms.As RNA silencing is being exploited as a technology in gene function studies in fungi as well as in engineering anti-fungal resistance in plants and animals,we also discuss the recent progress towards understanding dsRNA uptake in fungi.
