Critical electrolyte concentration of DNA-protein complexes in spermatozoal and somatic cell nuclei of the honey bee, Apis mellifera

• Published in: Insect biochemistry and molecular biology Vol. 26; no. 8; pp. 793 - 795
• Main Authors: Mello, Maria Luiza S., Falco, J.R.P.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1996
• Subjects: Apis mellifera; chromatin; concentration; Critical electrolyte concentration; DNA; DNA-protein complexes; electrolytes; HI histone; histones; Honey bee; nuclei; sperm transport; spermatheca; Spermatozoa; Critical electrolyte concentration; DNA-protein complexes; Spermatozoa; Honey bee; HI histone
• ISSN: 0965-1748; 1879-0240
• DOI: 10.1016/S0965-1748(96)00028-8

The binding of toluidine blue molecules to DNA phosphates under conditions of competitive staining with Mg
2+ was studied in nuclei of spermatozoa, and in the spermatheca and spermathecal glands of honey bee (
Apis mellifera) queens. The objective was to detect differences in the critical electrolyte concentration (CEC) for the chromatin of these cells, even though an H1 histone has also been assumed to occur in the spermatozoa of
A. mellifera. The CEC values were found to be the same for the different somatic cells analysed but to be higher in the spermatozoa, with even increased values after the lodging of these cells in the queen's spermatheca. A greater availability of DNA phosphates for the dye-Mg
2+ competitive binding action was thus demonstrated for the spermatozoa compared to the somatic cells in
A. mellifera. This is attributed to differences in their DNA-protein complexes, contributing to differences in chromatin packing states. The increased CEC found in the spermatozoa inside the spermatheca is certainly related to additional changes affecting the DNA-protein complex in the chromatin of the male cells after they penetrate the female tract.