Summary
The three-way differentiation of sister chromatids (3-way SCD) in M3 endoreduplicated chromosomes in a Bloom syndrome (BS) B-lymphoid cell line, suggested that in addition to exchanges between sister chromatids (intra-exchanges), non-sister chromatid exchanges (inter-exchanges) also occur, especially in BS high SCE cells. In BS diploid chromosomes such inter-exchanges probably get confused with intra-exchanges when total SCEs are accounted for. Bloom syndrome high SCE cells probably do not follow the same bromodeoxyuridine (BrdU) uptake pattern over three cell cycles as normal cells. The 3-way SCD in M3 endoreduplicated chromosomes can be explained on the basis of Schvartzman's second model (1979) as well as Miller's model (1976), depending on the pattern of uptake of BrdU over three cell cycles. An interference in the previous events of exchanges in the following cell cycle (i.e., cancellation of SCEs) in BS chromosomes was observed in some regions, though not in high numbers.
Similar content being viewed by others
References
Chaganti RSK, Schonberg S, German J (1974) A many-fold increase in sister chromatid exchanges in Bloom's syndrome lymphocytes. Proc Natl Acad Sci USA 71:4508–4512
Kato H (1977) Spontaneous and induced sister chromatid exchanges as revealed by the BUdR-labelling method. Int Rev Cytol 49:55–97
Kuhn EM (1981) A high incidence of mitotic chiasmata in endoreduplicated Bloom's syndrome cells. Hum Genet 58:417–421
Miller RC, Aronson MM, Nichols WW (1976) Effects of treatment on differential staining of BrdU-labeled metaphase chromosomes: three-way differentiation of M3 chromosomes. Chromosoma 55: 1–11
Ray JH, German J (1983) The cytogenetics of the “chromosome-breakage syndrome”. In: German J (ed) Chromosome mutation and neoplasia. Liss, New York, pp 135–167
Schvartzman JB (1979) Three-way diffirentiation of sister chromatids in 5-bromodeoxyuridine-substituted chromosomes. J Hered 70: 423–424
Schvartzman JB, Goyanes VJ, Campos A, Lage AM, Veiras C, Silva MC, Ramos S (1985) Persistence of DNA lesions and the cytological cancellation of sister chromatid exchanges. Chromosoma 92: 7–10
Shiraishi Y (1984) Analysis of sister chromatid exchanges in Bloom syndrome by use of endomitotic and three-way differentiation procedures. In: Tice RR, Hollaender A (eds) Sister chromatid exchanges: genetic toxicology and human studies, part B. Plenum Press, New York, pp 729–740
Shiraishi Y, Yosida TH, Sandberg AA (1982) Analysis of single and twin sister chromatid exchanges in endoreduplicated normal and Bloom syndrome B-lymphoid cells. Chromosoma 87:1–8
Shiraishi Y, Yosida TH, Sandberg AA (1983) Analyses of bromodeoxyuridine-associated sister chromatid exchanges (SCEs) in Bloom syndrome based on cell fusion: single and twin SCEs in endoreduplication. Proc Natl Acad Sci USA 80:4369–4373
Shiraishi Y, Yosida TH, Sandberg AA (1985) Inhibition of bromodeoxyuridine-associated sister chromatid exchanges in Bloom's syndrome cells with cycloheximide. Cancer Genet Cytogenet 17: 43–54
Taylor JH (1958) Sister chromatid exchanges in tritium-labeled chromosomes. Genetics 43:515–529
Taylor JH (1959) The organisation and duplication of genetic material. Proc X Int Genet 1:63–78
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bamezai, R., Shiraishi, Y. Three-way differentiation of sister chromatids in endoreduplicated (M3) chromosomes of Bloom syndrome B-lymphoid cell line. Hum Genet 75, 239–243 (1987). https://doi.org/10.1007/BF00281066
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00281066