THE EFFECTS OF IONIZED RADIATION TO MITOCHONDRIAL AND NUCLEAR DNA

Year 2017, Volume: Volume 2 Issue: İssue 1 (1) - 2.İnternational Congress Of Forensic Toxicology, 212 - 212, 16.02.2017

Emel Hülya Yükseloğlu Kadir Daştan Fatma Çavuş Gülten Rayımoğlu Dilek Salkım Işlek

Abstract

Ionized radiation is a well-known
mutagen leading to karyotypic anomalies at high doses, gene mutation and
amplification, cellular transformation, clonal heterogeneity and reproductive
cell death. Ionized radiation, gamma and alpha radiation in particular, may
have adverse effects on the analysis of DNA at a variety of biological
matrices.

Early studies had looked into
restricting effects of gamma radiation emanating from a cobalt-60 source, and
alpha particles which radiating from a particle accelerator, on successful DNA
profiling in qualitative and quantitative terms and identified the stability,
sample integrity and DNA degradation threshold doses of the post-irradiation
DNA sample. Higher doses of radiation in blood, saliva, bone and genomic DNA
lead to a progressive loss in loci with high-molecular weight and a decrease in
allele frequency while it is concluded that ionized radiation and mainly D18S51
as one of the largest target fragments interacts more with longer fragments.

Degradation in the DNA molecule
was shown to occur as fragmentation in the DNA strand, cross-linking among
strands, deamination and dimer formation. It is determined that biological
matrices exposed to gamma irradiation were relatively more resistant in terms
of DNA analysis, and a full DNA profile for up to 10,000 Gy dose can be
obtained while samples exposed to alpha irradiation were resistant to higher
doses.

It is revealed that point
mutations and deletions were accumulated in mitochondrial DNA due to ionized
radiation, thus led to a decrease in oxidative phosphorylation and an increase
in reactive oxygen derivatives. Besides, it is a known that the mitochondrial
genome exposed to ionized radiation is more fragile than the nuclear DNA. The
control site is the most polymorphic region of the mtDNA genome, and the damage
induced by ionized radiation is most commonly observed here. This damage is
dose-dependent, requiring 72 hours to reach a measurable level while it
manifest itself in both normal cells and tumors, and there is no correlation
with radiosensitivity.

 

 

Keywords

THE EFFECTS OF IONIZED RADIATION TO MITOCHONDRIAL AND NUCLEAR DNA

References

• Emel Hülya YÜKSELOĞLU, Kadir DAŞTAN, Fatma ÇAVUŞ, Gülten RAYIMOĞLU, Dilek SALKIM IŞLEK
• Istanbul University Institute of Forensic Sciences, 34303, Cerrahpasa, Istanbul, Turkey YeniYuzyil University, Faculty of Health Sciences, Cevizlibag, Topkapı, Istanbul, Turkey