Relationship between the DNA content of human chromosomes and their involvement in radiation-induced structural aberrations, analysed by painting

Abstract

Purpose : To study the relationship between the DNA content of human chromosomes and their involvement in radiation-induced structural chromosome aberrations. Material and methods : Human lymphocytes were cultured after exposure to 5 Gy of X-rays. FISH-painting was performed for all human chromosomes. Results : The results indicate that with the exception of chromosome 20, there was a good fit between the DNA content and the number of exchange-type aberrations and the number of breaks. However, there was a significant tendency for short chromosomes to be more a ffected than expected and for long chromosomes to be less affected than expected. A better fit was observed when, instead of DNA content, the surface area of the chromosome territories obtained from a spherical model was taken into consideration. Conclusions : The tendency for short chromosomes to be more involved and long chromosomes to be less involved in exchangetype aberrations could be related not only to their DNA content but also to their interphase territory surface area.