title: Aanlysis of the frequency and distribution of sister chromatid exchanges in cultured human lymphocytes.
abstract: Lymphocytes from 20 notmal subjects (11 male and 9 female) were examined for the frequency and location of sister chromatid exchanges (SCE) by the BrdU--Giemsa method. The mean frequency of SCE was 6.37 with little significant variation. One subject had a high number of exchanges in chromosome 1 while the remainder showed a random distribution of exchanges between chromosomes. The frequency of exchanges generally increased with chromosome length. However, chromosome 1, 2 and the B group had more exchanges than expected while the E, F and G grous had less than expected. The distribution of exchanges in chromosomes 1, 2 and the B group was non-random with a concentration of exchanges below the centromere and to a lesser extent on the distal portion of the long arm. The majority of exchanges appeared to occur at the junction between the dark and light G bands. It is suggested that the concentration of exchanges may reflect differences in BrdU incorporation along the length of the chromosome.
mesh_terms: D001973:Bromodeoxyuridine; D002842:Chromatids; D002900:Chromosomes, Human, 1-3; D002905:Chromosomes, Human, 4-5; D003434:Crossing Over, Genetic; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008214:Lymphocytes / Q000166:cytology; D008297:Male
chemical_list: D001973:Bromodeoxyuridine