Cytochemical Tests for Sperm Chromatin Maturity

Human Sperm Chromatin Undergoes Physiological Remodeling During In Vitro Capacitation and Acrosome Reaction

“…In addition, increases in the stains were mostly intermediate (white portion of the bars in Figures 1 and 3), as observed with other CAP‐related events (de Lamirande et al, 1997, 1998; Olds‐Clarke, 2003; De Jonge, 2005; O'Flaherty et al, 2006b; de Lamirande and O'Flaherty, 2008). Finally, changes such as those seen in Figures 1 and 3 could be reproduced by a mild treatment of smears with SDS or DTT that affects chromatin compaction without inducing DNA damage (Krzanowska, 1982; Marchesi et al, 2010; Tsarev and Erenpreiss, 2011). For these reasons, our data are really distinct from those related to spermatozoa from infertile men, in which the %DFI is high and positive nuclear staining (such as AB or TB) is mostly seen on clearly abnormal heads (Erenpreisa et al, 2003; Agarwal et al, 2008; Barratt et al, 2010; Marchesi et al, 2010; Abbasi et al, 2011; Tsarev and Erenpreiss, 2011); they rather present what is happening to sperm chromatin during physiological cell activation (CAP and AR).…”

“…Finally, changes such as those seen in Figures 1 and 3 could be reproduced by a mild treatment of smears with SDS or DTT that affects chromatin compaction without inducing DNA damage (Krzanowska, 1982; Marchesi et al, 2010; Tsarev and Erenpreiss, 2011). For these reasons, our data are really distinct from those related to spermatozoa from infertile men, in which the %DFI is high and positive nuclear staining (such as AB or TB) is mostly seen on clearly abnormal heads (Erenpreisa et al, 2003; Agarwal et al, 2008; Barratt et al, 2010; Marchesi et al, 2010; Abbasi et al, 2011; Tsarev and Erenpreiss, 2011); they rather present what is happening to sperm chromatin during physiological cell activation (CAP and AR). Although it is possible that one of the stains might penetrate more easily because of cellular events independent of chromatin remodeling, it is unlikely that all the stains would behave in the same manner.…”

“…Their interaction with DNA or its associated proteins should allow evaluating the physiological effects of CAP and AR on sperm chromatin. These stains are simple and efficient and do not require expensive equipment (Oliva et al, 1992; Chatterjee et al, 2001; Erenpreiss et al, 2001; Erenpreisa et al, 2003; Agarwal et al, 2008; Tsarev and Erenpreiss, 2011). TB interacts with free phosphate residues in the DNA backbone (Erenpreiss et al, 2001; Marchesi et al, 2010).…”

“…Aniline blue (AB) binds to Lys‐rich nuclear proteins and mostly histones in spermatozoa (Dadoune et al, 1988; Liu and Baker, 1992; Agarwal et al, 2008; Tsarev and Erenpreiss, 2011). In infertile men, spermatozoa with dark staining are often obviously abnormal and considered immature (Erenpreiss et al, 2001; Agarwal et al, 2008).…”

“…In infertile men, spermatozoa with dark staining are often obviously abnormal and considered immature (Erenpreiss et al, 2001; Agarwal et al, 2008). Yet it is plausible that a mild change in chromatin conformation during physiological processes such as CAP and/or AR could also render histones more available to AB (Hammoud et al, 2009; Barratt et al, 2010; Balhorn, 2011; Oliva and Castillo, 2011; Tsarev and Erenpreiss, 2011).…”