In vivo chromosomal instability and transmissible aberrations in the progeny of haemopoietic stem cells induced by high- and low-LET radiations.
OBJECTIVE
To study stable and unstable chromosomal aberrations in the haemopoietic cells of CBA/H mice after exposure to both high- and low-LET radiations.


METHODS
Chromosomal aberrations were scored in the clonal progeny of X-, alpha- or non-irradiated short-term repopulating stem cells using the spleen colony-forming unit (CFU-S) assay, 12 days post-transplantation and in the bone marrow reconstituted by X-, neutron- or non-irradiated exogenous (transplanted) or endogenous (X- or neutron whole-body-irradiated) long-term repopulating stem cells for up to 24 months.


RESULTS
Chromosomal instability was demonstrated in 3-6% of cells in all cases. After transplantation of X- or neutron-irradiated bone marrow approximately 8% of cells with stable aberrations were recorded at all times. After 3Gy X- or 0.5 Gy neutron- whole-body irradiation stable aberrations were detected in approximately 17 and 5% of cells respectively.


CONCLUSIONS
Chromosomal instability induced in vitro can be transmitted in vivo by transplantation of haemopoietic stem cells exposed to high- or low-LET radiations. Comparable instability can be induced and shown to persist for the remaining lifetime after whole-body irradiation. There was no direct relationship between the expression of stable and unstable aberrations and significant interanimal variation in the expression of both stable and unstable aberrations.
Watson
G E
GE
Radiation and Genome Stability Unit, Medical Research Council, Harwell, UK.
Pocock
D A
DA
Papworth
D
D
Lorimore
S A
SA
Wright
E G
EG
D000818:Animals; D002869:Chromosome Aberrations; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000528:radiation effects* / Q000648:ultrastructure; D018499:Linear Energy Transfer; D051379:Mice; D008808:Mice, Inbred CBA; D014916:Whole-Body Irradiation; D014965:X-Rays