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SHAPES OF THE U.V. INACTIVATION CURVES FOR SINGLE AND LINKED DOUBLE MARKERS IN HAEMOPHILUS INFLUENZAE TRANSFORMING DNA *
Author(s) -
RUPERT C. S.
Publication year - 1968
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1968.tb07405.x
Subject(s) - inverse , physics , dna , power law , square (algebra) , inverse square law , haemophilus influenzae , law , genetics , biology , statistics , mathematics , quantum mechanics , geometry , bacteria , gravitation , political science
The known inverse square law S = 1/(1+ CD ) 2 , relating survival of transforming activity S to ultraviolet (u.v.) dose D, C being a constant, fails for two linked‐double genetic markers in H. influenzae. For these double markers the law is S = 1/(1+ CD ) 4 , both for u.v. and nitrous acid inactivation. A theoretical model which predicts the inverse square law for singles also predicts the inverse fourth power law for linked doubles, if the possibility of an even number (>0) of genetic recombinations between the markers is allowed for. However, it can be shown rather generally that other models, not specified in exact detail, can lead to the same inverse square law for single markers, and thus to the inverse fourth power law for sufficiently separated linked‐doubles. Ability to predict these laws is not, therefore, strong evidence for the validity of any one model. For all these models, the mean number of damaging lesions per unit length of DNA is directly proportional to dose, making (√(1/ S )–1) for single markers and (√(1/ S )–1) for loosely linked‐doubles a reasonable biological measure of inactivating damage in the DNA.