Malsegregation as a Possible Mechanism of Aneuploidy

SEOANE, ANALÍA; GUERCI ALBA; DULOUT FERNANDO

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS

Wiley-Liss

Lugar: Wilmington, USA; Año: 2002 vol. 40 p. 200 - 206

0893-6692

one or more components of the mitotic apparatusleading to an erroneous migration of chromosomes.Malsegregation occurs when a chromosome(or a chromatid) fails to migrate and remainsat the metaphase plate. Nondisjunction implies thelack of dissociation between sister chromatids andthe migration of both together to the same pole.The aim of the present study was to provide evidencethat the aneugenic effect of some metal saltsis the consequence of malsegregation at anaphaseand that it is not caused by nondisjunction mechanisms.The frequencies of lagging chromosomes atanaphase-telophase of mitosis, hypoploid metaphases,and kinetochore-positive micronuclei inducedby cadmium chloride, potassium dichromate,and cacodilic acid (dimethylarsinic acid) inMRC-5 human cells were compared. The data indicatethat all the tested compounds are able toinduce aneuploidy in MRC-5 human cells. Positive,statistically significant correlations were found whenkinetochore-positive micronuclei, hypoploidy, andlagging chromosome frequencies were compared.The results suggest that malsegregation is the mainmechanism involved in the induction of aneuploidy bymetal salts in MRC-5 cells. Environ. Mol. Mutagen.40:200–206, 2002. © 2002 Wiley-Liss, Inc.