Symmetric chromosomal order in leukocytes indicated by DNA image cytometry and fluorescence in situ hybridization.

OBJECTIVE

To study if the symmetry observed in the nuclear structure of polymorphonuclear cells (PNC) could be verified functionally by determining DNA and chromosome distributions using image cytometry (ICM) and fluorescence in situ hybridization (FISH) STUDY

DESIGN

In murine and human leukocytes the proportion of PNCs with apparently bilaterally symmetric nuclei was determined. By ICM, total nuclear DNA and DNA content in each half of these nuclei were measured. For chromosomal localization the FISH technique was applied.

RESULTS

About 13% of PNC nuclei appeared to be bilaterally symmetric. ICM of Feulgen DNA revealed that the PNC had a 2N value, similar to mononuclear cells. The DNA content in each of the two symmetric parts of the nucleus was exactly the same. Similarly, FISH signals specific to chromosomes 1 and 2 were distributed bilaterally on the two symmetric parts.

CONCLUSION

The distribution of DNA and chromosomes studied support the hypothesis of bilateral symmetry of PNC nuclei, suggesting haploid separation. This specific distribution may be valuable for the study of mechanisms leading to DNA and chromosome damage by exposures to chemicals or radiation and may have far-reaching significance in genetics regarding imprinting, meiotic pairing and other subjects.