Induced and spontaneous chromosomal aberrations in cultured human leukocytes

• Main Author: Andrews, John Charles
• Language: English
• Published: University of British Columbia 2011
• Subjects: Chromosomes; Leucocytes; Chromosome Aberrations
• Online Access: http://hdl.handle.net/2429/35556

The frequency of chromosome breaks was increased in replicate cultures from each of ten individuals when lysergic acid diethylamide at a concentration of 1 ug/ml of culture was added 24 hours prior to the harvest of the cells. The differences between the control and treated cultures ranged from +3.00 to +7.93 with a mean of +4.63, indicating no variation in response between individuals. The breaks were randomly distributed among the seven groups of chromosomes of the complement. No significant difference in either the number of cells with aberrations, or the number of breakage events was observed between cells cultured from a patient with Fanconi's anaemia before and 24 hours after treatment with 250 ug. of growth hormone. Both were significantly increased over the control. After treatment with growth hormone, the number of breaks per aberrant cell was decreased, and the distribution of frequencies of specific types of aberrations was changed. Non-homologous exchange figures were the only two break events observed in cultures from the patient. None were observed in control cells. The distribution of breaks among the seven groups of chromosomes was random. The frequency of chromosome aberrations was increased in cultures from a single individual when treated with 1 ug/ml of mitomycin-C for one hour at the beginning of the culture period. In the treated cultures, 181 breaks were observed in 64 of the 100 cells examined, whereas only 5 breaks were observed in three of the 100 cells scored in the control samples. Forty-seven exchange configurations were observed in the treated cultures, 42.56% of these being non-homologous exchanges. No marker or dicentric chromosomes were observed. Breaks were randomly distributed among the seven groups of chromosomes of the complement. === Medicine, Faculty of === Medical Genetics, Department of === Graduate