Spermatocyte Spreading during Meiotic Cell Preparation is a Two StepProcess

Abstract

Cytological techniques have been instrumental for the investigation of meiosis and gametogenesis. Especially high resolution chromatin spreads of male and female germline cells provide for detailed insights into the molecular mechanisms acting during germ cell differentiation. Most spreading techniques for germ cells are done with a hypotonic detergent solution followed by an extended drying period. Using video microscopy and we monitored the course of mouse spermatocyte spreading after exposure to graded concentrations of the ionic detergent mixture Lipsol that is known to efficiently spread meiocytes. Our analysis disclosed that spreading of meiotic cells is optimal at a final detergent concentration of about 0.7% and occurs in two phases. First, cells undergo slow swelling in the dilute detergent solution (lasting up to >1 h) followed by rapid dispersion of the nuclear chromatin over the glass surface just prior to the final evaporation of the water in the solution. These results provide a better understanding of an important technique in meiosis research and identify factors determining the spreading process.