8‐Oxoguanine DNA glycosylase1 (OGG1)‐initiated base excision repair (BER) is the primary pathway to remove the pre‐mutagenic 8‐oxo‐7,8‐dihydroguanine (8‐oxoG) from DNA. Recent studies documented 8‐oxoG serves as an epigenetic‐like mark and OGG1 modulates gene expression in oxidatively stressed cells. For this new role of OGG1, two distinct mechanisms have been proposed: one is coupled to base excision, while the other only requires substrate binding of OGG1––both resulting in conformational adjustment in the adjacent DNA sequences providing access for transcription factors to their cis‐elements. The present study aimed to examine if BER activity of OGG1 is required for pro‐inflammatory gene expression. To this end, Ogg1/OGG1 knockout/depleted cells were transfected with constructs expressing wild‐type (wt) and repair‐deficient mutants of OGG1. OGG1's promoter enrichment, oxidative state, and gene expression were examined. Results showed that TNFα exposure increased levels of oxidatively modified cysteine(s) of wt OGG1 without impairing its association with promoter and facilitated gene expression. The excision deficient K249Q mutant was even a more potent activator of gene expression; whereas, mutant OGG1 with impaired substrate recognition/binding was not. These data suggested the interaction of OGG1 with its substrate at regulatory regions followed by conformational adjustment in the adjacent DNA is the primary mode to modulate inflammatory gene expression.
Plant bugs (Miridae species) have become major agricultural pests that cause increasing and severe economic damage. Plant‐mediated RNA interference (RNAi) is emerging as an eco‐friendly, efficient, and reliable strategy for pest management. In this study, we isolated and characterized a lethal gene of Apolygus lucorum and named it Apolygus lucorum LIM (AlLIM), which produced A. lucorum mortality rates ranging from 38% to 81%. Downregulation of the AlLIM gene expression in A. lucorum by injection of a double‐stranded RNA (dsRNA) led to muscle structural disorganization that resulted in metamorphosis deficiency and increased mortality. Then we constructed a plant expression vector that enabled transgenic cotton to highly and stably express dsRNA of AlLIM (dsAlLIM) by Agrobacterium‐mediated genetic transformation. In the field bioassay, dsAlLIM transgenic cotton was protected from A. lucorum damage with high efficiency, with almost no detectable yield loss. Therefore, our study successfully provides a promising genetically modified strategy to overpower A. lucorum attack.
Biometrics deals with the recognition of humans based on their unique physical characteristics. It can be based on face identification, iris, fingerprint and DNA. In this paper, we have considered the iris as a source of biometric verification as it is the unique part of eye which can never be altered, and it remains the same throughout the life of an individual. We have proposed the improved iris recognition system including image registration as a main step as well as the edge detection method for feature extraction. The PCA-based method is also proposed as an independent iris recognition method based on a similarity score. Experiments conducted using our own developed database demonstrate that the first proposed system reduced the computation time to 6.56 sec, and it improved the accuracy to 99.73, while the PCA-based method has less accuracy than this system does.
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