genomic DNA

About: genomic DNA is a research topic. Over the lifetime, 15046 publications have been published within this topic receiving 663636 citations. The topic is also known as: genomic deoxyribonucleic acid & gDNA.

Relationships among ancestral species of sugarcane revealed with RFLP using single copy maize nuclear probes

Abstract: DNA restriction fragment length polymorphism (RFLP) analysis was performed on 50 wild and old cultivated sugarcane accessions Ninety-four maize low copy nuclear DNA sequences of known chromosomal position were screened for hybridization to digested sugarcane genomic DNA blots Seventy-five (80%) gave very strong hybridization signals and usually yielded many bands and detected profuse polymorphism Twenty-nine probes and 36 probe/enzyme combinations were selected on the basis of the scorability of the banding profiles A total of 1110 fragments were separately identified among the 50 genotypes Multivariate analyses of the data allowed the separation of the three basic species, Saccharum spontaneum, S robustum and S officinarum, showed that S spontaneum had structure which could be related to the geographic origin of the clones and supported current hypotheses on the origin of secondary species S barberi and S sinense The use of more probes did not improve the resolution between the various species examined but identified a few key polymorphisms which were not accounted for by current phylogenetic hypotheses and can guide future analyses RFLPs in sugarcane will be useful essentially for depicting the genomic constitution of modern varieties of interspecific origin

Transcriptional activation of short interspersed elements by DNA-damaging agents

Abstract: Short interspersed elements (SINEs), typified by the human Alu repeat, are RNA polymerase III (pol III)-transcribed sequences that replicate within the genome through an RNA intermediate. Replication of SINEs has been extensive in mammalian evolution: an estimated 5% of the human genome consists of Alu repeats. The mechanisms regulating transcription, reverse transcription, and reinsertion of SINE elements in genomic DNA are poorly understood. Here we report that expression of murine SINE transcripts of both the B1 and B2 classes is strongly upregulated after prolonged exposure to cisplatin, etoposide, or gamma radiation. A similar induction of Alu transcripts in human cells occurs under these conditions. This induction is not due to a general upregulation of pol III activity in either species. Genotoxic treatment of murine cells containing an exogenous human Alu element induced Alu transcription. Concomitant with the increased expression of SINEs, an increase in cellular reverse transcriptase was observed after exposure to these same DNA-damaging agents. These findings suggest that genomic damage may be an important activator of SINEs, and that SINE mobility may contribute to secondary malignancy after exposure to DNA-damaging chemotherapy.