Background: Chromomycin A3 (CMA3) staining is one of the staining methods for detecting protamine deficiency in sperm nucleus. CMA3 is a fluorochrome that competes with protamines for binding to DNA double helix. It has been shown in our previous studies that percentage of CMA3 positive spermatozoa in semen has a close significant relationship with the fertilization rate in in vitro fertilization (IVF). The aim of this study was to examine the ultrastructural differences between sperms in patients who had high fluorescent percentages of yellow or red in CMA3 staining (protamine deficient) with patients with low fluorescent percentages.
Materials and methods: Semen samples are taken from five patients with high fluorescent percentages and five patients with low fluorescent percentages. Then the samples are passed for the different steps of preparing for electron microscopy. After the sectioning and mounting on grids, they are investigated under the transmission electron microscope.
Results: Sperms in patients with low percentages of positive spermatozoa often have a normal appearance. Sperms in high fluorescent samples frequently have unpacked chromatin. Furthermore acrosomes of these sperms are thinner or disturbed. Also sometimes there are irregularities in sperm head membrane.
Conclusion: Protamine deficiency in sperm nucleus can cause ultrastructural anomalies in sperm chromatin such as unpacking of it. It also is concomitant with acrosome and sperm membrane disturbances.
Keywords: Chromatin; chromomycinA3; spermatozoa; ultrastructure.