Radiation damage genetic

W. L. Russell in "Repair from Genetic Radiation Damage and Differential Radiosensitivity to Germ Cells," F. H. Sobels, Ed., Pergamon Press, London, 1963, p. 206. 

Explain, with examples, the difference between somatic and genetic radiation damage. 

Photodimerization of thymin to butane type dimers is one of the important causes of UV radiation damage to genetic material DNA in its native double helix form. The reaction occur from the triplet state as confirmed by acetone sensitized photodimerization of thymine. These dimers can be monomerized when irradiated by short wavelength radiations. which are absorbed by the dimer only. 

Chromosome anomalies and aberrations can influence heredity. Most somatic cells of humans contain 23 pairs of chromosomes, with one member of each pair contributed by the sperm and the other contributed by the egg. When the process of sperm or egg cell production goes awry as a result of radiation damage, abnormal chromosome numbers (aneuploidy) can arise. Aneuploidy is a form of genetic instability. 

ATP-dependent deoxyribonucleases (DNase) are enzymes that hydrolyze the phosphodiester linkage between deoxyribonucleosides in the presence of ATP. These enzymes are thought to be involved in the processes of genetic recombination and repair of radiation damages. The ATP-dependent DNase from Micrococcus luteus (Mw 160 kDa) shows the activity for single or double stranded linear DNA via an end-attachment 3 5 exonucleolytic processive... 

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