Sperm nuclear instability and staining with aniline blue: abnormal persistance of histones in spermatozoa in infertile men

Abstract

During mammalian spermiogenesis, replacement of the somatic histones by basic proteins, the protamines, allows normal sperm nuclear condensation. In this study we have evaluated the degree of chromatin compaction in spermatozoa from 191 infertile subjects, affected by different testicular disorders, compare with that in 50 fertile sperm donors (controls). In infertile men, there was a higher percentage of unstable spermatozoa after incubation with sodium dodecyl sulphate (SDS) and of stained spermatozoa after staining with aniline blue (P less than 0.001 vs. controls). Furthermore, a positive linear correlation was found between SDS-unstable spermatozoa and stained spermatozoa (P less than 0.001), suggesting that sperm instability was related to a defect in histone-replacement by sperm-specific nucleoproteins, protamines. When the patients were considered according to pathology, high sperm nuclear instability and a high percentage of stained spermatozoa were detected in groups affected by varicocele, idiopathic infertility and in patients with a history of unilateral cryptorchidism. In the latter group the same alterations were observed even when the cryptorchid testis had been removed during surgery. In the group with a past history of mumps orchitis these parameters did not show any difference when compared with controls.

Chromatin packaging and morphology in ejaculated human spermatozoa: evidence of hidden anomalies in normal spermatozoa

“…When we compared the morphology and CMA 3 fluorescence in individual spermatozoa, we found a high frequency of CMA 3 positive nuclei among macrocephalic spermatozoa in both treatment groups. This confirms data known on other fluorescent dyes, in particular Acridine Orange, where access to the DNA was achieved only or mostly in cases of decondensed or damaged chromatin (Evenson et al, 1980;1991;Foresta et al, 1992;Molina et al, 1995;Sailer et al, 1995). Our observations also confirm that macrocephaly is associated with decondensation.…”

“…A number of studies have shown that spermatozoa with abnormal nuclear chromatin organization are more frequent in infertile men than in fertile men (Evenson et al, 1980;Monaco and Rasch, 1982;Foresta et al, 1992). In these studies, specific dyes and fluorochromes were used to assess the chromatin of mature mammalian spermatozoa and relate them to fertilization results.…”

Human Cervical Mucus Can Act in Vitro as a Selective Barrier Against Spermatozoa Carrying Fragmented Dna and Chromatin Structural Abnormalities

“…In this connection, it must be remembered that several studies have demonstrated that a variable but consistent fraction of human spermatozoa exhibits abnormalities in chromatin structure, not always detected using classical parameters of evaluation (12)(13)(14)(15)(16)(17)(18)(33)(34)(35). Moreover the existence of a close relationship between chromatin and DNA structural abnormalities and male infertility has been well pointed out.…”

Heterologous murine and bovine IVF using bottlenose dolphin (Tursiops truncatus) spermatozoa

“…In contrast, in the Asian elephant, a terrestrial endorchid, it has been aniline blue, which is taken up by the abundant lysine residues present in the histones. A 595 significant association between defective abnormal sperm chromatin protamination and male subfertility has been reported [71][72][73]. Relationship between chromatin stability, protamination and fertility would provide fundamental information on chromatin status, which is expected to have a strong prognostic value on sperm function [39,74].…”