The molecular nature of mutants induced by X rays is altered by the presence of the radioprotector cysteamine.

The molecular structure of mutants induced in human lymphoblast cells by 500 cGy X rays in the presence of the radioprotector cysteamine (25 mM) has been compared with that induced by an equally mutagenic treatment of 150 cGy X rays alone. Sets of mutants at the hypoxanthine-guanine phosphoribosyl transferase locus were analyzed by Southern blot. Of 24 mutants induced by X rays in the presence of cysteamine, 67% exhibited no change in the restriction fragment pattern and thus were defined as point mutations; 8% appeared to be total gene deletions and 25% were partial deletions or rearrangements.

Formaldehyde-induced and spontaneous alterations in human hprt DNA sequence and mRNA expression.

Human lymphoblast mutants at the X-linked hprt locus have been examined by Southern blot, Northern blot and DNA sequence analysis. A previous study had shown that approximately a third of the spontaneously-arising mutants and half those induced by formaldehyde showed no alteration in restriction fragment pattern and thus were classified as point mutations. In this report, Northern blot analysis was used to show that these point mutants fall into 4 categories: normal size and amount of RNA, normal size but reduced amounts, reduced size of RNA or no RNA.

Molecular analysis of formaldehyde-induced mutations in human lymphoblasts and E. coli.

The molecular nature of formaldehyde (HCHO)-induced mutations was studied in both human lymphoblasts and E. coli. Thirty HPRT- human lymphoblast colonies induced by eight repetitive 150 microM HCHO treatments were characterized by Southern blot analysis.

The effects of dominance on mating behavior and paternity in a captive troop of rhesus monkeys (Macaca mulatta).

The effects of social dominance on male mating behavior and paternity in a troop of rhesus monkeys (macaca mulatta) were examined. A wild-caught troop of monkeys, captured in India in 1972, has been monitored in captivity for eight years. Some animals have been culled from this troop, but no new animals have been added except through births.