Chromosome Tracking in Fused Cells by Single Nucleotide Polymorphisms

Abstract

Single nucleotide polymorphisms (SNP) refer to single-base differences in DNA sequence between individuals of the same species. In experimental setting, inbred mouse strains can easily be distinguished by their typical SNPs. Therefore, if cell fusion partners are selected to originate from two different genotypes the detection of strain specific SNPs in the genome of fused cells can be utilized as a complimentary method to traditional karyotyping and cell ploidy analyses to monitor the success of the cell fusion procedure and identification of chromosomes from both genotypes in established fusion cell lines. In this chapter, we describe the method for selection and detection of SNPs on each of the 23 pairs of murine chromosome in cell hybrids generated by fusion of murine somatic cells originating from DBA/2J female mice and murine embryonic stem (ES) cells originating from 129/Ola male mice. While parental fusing partners show the presence of only a single strain specific allele the tetraploid fusion hybrid cells harbor alleles originating from both fusing partners indicating that the fusion clones retained both parental nuclei and at least one of each pair of parental autosomes, which were not lost in the course of cell expansion.