Centro de Documentação da PJ
Monografia
 CD200 |
Double strand break repair of highly damaged DNA [Documento electrónico] : final report / Jack Ballantyne.- [Orlando, FL] : ed. do a., 2009, 2011.- 1 CD-ROM ; 12 cm
Research report submitted to the Department of Justice, National Institute of Justice - Award Number: 2006-DN-BX-K005. Ficheiro de 933 KB em formato PDF (98 p.). Disponível também em: https://www.ncjrs.gov/pdffiles1/nij/grants/236690.pdf. Acedido a 01 de junho de 2012.
PRESERVAÇÃO DA PROVA, ADN, ANÁLISE DE VESTÍGIOS, BIOLOGIA FORENSE
DNA extracted from biological stains is often intractable to analysis. This may be due to a number of factors including a low copy number of starting molecules, the presence of soluble inhibitors or damaged DNA templates. Remedies may be available to the forensic scientist to deal with LCN templates and soluble inhibitors but none presently exist for damaged DNA. Previous work in this laboratory has shown that double strand and single strand breaks are significant contributors to the non-typeability of damaged DNA templates extracted from forensic-type stains (i.e. dried biological stains exposed to a myriad of environmental insults). This proposal sought to repair double strand breaks, restoring sufficient genomic integrity to permit DNA typing, using single nucleotide polymorphism loci (SNPs) as a model system. Three methods were developed and tested. The first is a simple gap filling prior to strand denaturation during the DNA amplification process. The second requires the addition of in vitro synthesized repair substrates that are complementary to the sequences flanking a SNP on both DNA strands, providing a matrix for repair polymerization and facilitating the recovery of amplifiable fragments. The third method involved the biochemical reconstitution of the non-homologous end joining (NHEJ) pathway, one of the principal cellular recombinational DNA repair pathways. While the substrate mediated gap repair system demonstrated some evidence of in vitro repair using artificial genomic templates, all attempts at repair of genomic DNA using any of the repair methods failed. We believe that the sequence complexity of genomic DNA provides an insurmountable computational barrier to reconstituting two contiguous fragments of DNA back to its native state, a requirement for the successful repair of double strand breaks.