Biomaterial Database

Heavy ion-induced DNA double-strand breaks with yeast as a model system. 1995

S Ikpeme, and M Löbrich, and T Akpa, and E Schneider, and J Kiefer

Strahlenzentrum der Justus-Liebig-Universität Giessen, Germany.

Cells of diploid yeast, Saccharomyces cerevisiae, were exposed to a variety of energetic heavy ions (provided by the UNILAC facility at the Gesellschaft für Schwerionenforschung, GSI), 241Am alpha-particles and 80-keV x-rays after which they were assessed for DNA double-strand breaks (DSB) using either the neutral sedimentation or the pulsed-field gel electrophoresis (PFGE) technique. Both yielded comparable results. The DSB production cross-sections are compared with inactivation studies performed for the same cells under identical conditions. The measurements show that with lighter ions DSB induction cross-sections increase with linear energy transfer (LET), but the situation is less clear with the heavier ions. A close parallelism was found between DSB induction and cell inactivation in these yeast cells.

UI	MeSH Term	Description	Entries
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D000512	Alpha Particles	Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.	Alpha Rays,Alpha Radiation,Radiation, Alpha,Alpha Particle,Alpha Ray,Particle, Alpha,Particles, Alpha,Ray, Alpha,Rays, Alpha
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D014965	X-Rays	Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.	Grenz Ray,Grenz Rays,Roentgen Ray,Roentgen Rays,X Ray,X-Ray,Xray,Radiation, X,X-Radiation,Xrays,Ray, Grenz,Ray, Roentgen,Ray, X,Rays, Grenz,Rays, Roentgen,Rays, X,X Radiation,X Rays,X-Radiations
D016521	Electrophoresis, Gel, Pulsed-Field	Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.	Electrophoresis, Gel, Pulsed-Field Gradient,Gel Electrophoresis, Pulsed-Field,Contour-Clamped Homogeneous-Field Gel Electrophoresis,Electrophoresis, Gel, Pulsed Field,Electrophoresis, Pulsed Field Gel,Field Inversion Gel Electrophoresis,Orthogonal Field Alternation Gel Electrophoresis,Orthogonal-Field Alternation-Gel Electrophoresis,Pulsed Field Gradient Gel Electrophoresis,Pulsed-Field Gel Electrophoresis,Pulsed-Field Gradient Gel Electrophoresis,Alternation-Gel Electrophoresis, Orthogonal-Field,Contour Clamped Homogeneous Field Gel Electrophoresis,Electrophoresis, Orthogonal-Field Alternation-Gel,Electrophoresis, Pulsed-Field Gel,Gel Electrophoresis, Pulsed Field,Pulsed Field Gel Electrophoresis
D018499	Linear Energy Transfer	Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).	Energy Transfer, Linear,LET,Transfer, Linear Energy