Human erythrocyte PIG‐A assay: An easily monitored index of gene mutation requiring low volume blood samples. (20th November 2014)

• Record Type: Journal Article
• Authors: Dertinger, Stephen D.; Avlasevich, Svetlana L.; Bemis, Jeffrey C.; Chen, Yuhchyau; MacGregor, James T.
• Is Part Of: Environmental and molecular mutagenesis. Volume 56:Number 4(2015:May)
• Page Start: 366
• Page End: 377
• Publication Date: 2014-11-20
• Subjects: PIG‐A gene -- mutation -- flow cytometry -- peripheral blood -- CD59 -- CD55; Mutagenesis -- Periodicals; Molecular genetics -- Periodicals; Mutagenèse -- Périodiques; Mutagenèse chimique -- Périodiques; Mutation -- Périodiques; Maladies de l'environnement -- Périodiques; Génétique moléculaire -- Périodiques; 576.542
• DOI: 10.1002/em.21924
• Languages: English
• ISSNs: 0893-6692

Abstract

Abstract : This laboratory has previously described a method for scoring the incidence of rodent blood Pig‐a mutant phenotype erythrocytes using immunomagnetic separation in conjunction with flow cytometric analysis (In Vivo MutaFlow®). The current work extends this approach to human blood. The frequencies of CD59‐ and CD55‐negative reticulocytes (RET CD59−/CD55− ) and erythrocytes (RBC CD59−/CD55− ) serve as phenotypic reporters of PIG‐A gene mutation. Immunomagnetic separation was found to provide an effective means of increasing the number of reticulocytes and erythrocytes evaluated. Technical replicates were utilized to provide a sufficient number of cells for precise scoring while at the same time controlling for procedural accuracy by allowing comparison of replicate values. Cold whole blood samples could be held for at least one week without affecting reticulocyte, RET CD59−/CD55− or RBC CD59−/CD55− frequencies. Specimens from a total of 52 nonsmoking, self‐reported healthy adult subjects were evaluated. The mean frequency of RET CD59−/CD55− and RBC CD59−/CD55− were 6.0 × 10 −6 and 2.9 × 10 −6, respectively. The difference is consistent with a modest selective pressure against mutant phenotype erythrocytes in the circulation, and suggests advantages of studying both populations of erythrocytes. Whereas intra‐subject variability was low, inter‐subject variability was relatively high, with RET CD59−/CD55− frequencies differing by more than 30‐fold. There was an apparent correlation between age and mutant cell frequencies. Taken together, the results indicate that the frequency of human PIG‐A mutant phenotype cells can be efficiently and reliably estimated using a labeling and analysis protocol that is well established for rodent‐based studies. The applicability of the assay across species, its simplicity and statistical power, and the relatively non‐invasive nature of the assay should benefit myriad research areas involving DNA damage, including studies of environmental factors that modify "spontaneous" mutation frequencies. Environ. Mol. Mutagen. 56:366–377, 2015. © 2014 Wiley Periodicals, Inc.