Characterisation of a human sperm cell subpopulation marked by the presence of the TSH2B histone.
During the process of mammalian spermiogenesis, a significant reorganisation of the chromatin structure occurs involving the sequential substitution of somatic histones with protamines. In the human sperm nucleus, approximately 15% of the basic nuclear protein complement is maintained as histones. Human testis/sperm-specific histone H2B (hTSH2B) is a variant of the histone H2B expressed exclusively in spermatogenic germline cells and present in some mature sperm cells. Thus, this protein marks a subpopulation of sperm cells in the ejaculate. Using indirect immunofluorescence, we examined the influence of hTSH2B on zona pellucida binding and sperm head decondensation in amphibian egg cell-free extract. As suggested by previous studies, we found that hTSH2B can be localised in only approximately 30% of sperm cells within a given ejaculate. We established that the presence of hTSH2B does not influence sperm zona pellucida binding capacity. Finally, we found that decondensation occurred more rapidly and to a greater extent in those cells containing hTSH2B. We propose that the presence or absence of hTSH2B within spermatozoa influences pronuclei formation and the activation of paternal genes following fertilisation and during early embryonic development.
Singleton
Stephanie
S
The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, 601 Colley Avenue, Norfolk, VA 23507, USA.
Mudrak
Olga
O
Morshedi
Mahmood
M
Oehninger
Sergio
S
Zalenskaya
Irina
I
Zalensky
Andrei
A
D000818:Animals; D002457:Cell Extracts / Q000494:pharmacology; D019084:Fluorescent Antibody Technique, Indirect; D006657:Histones / Q000032:analysis* / Q000502:physiology*; D006801:Humans; D008297:Male; D010063:Ovum / Q000502:physiology; D013094:Spermatozoa / Q000737:chemistry* / Q000187:drug effects / Q000502:physiology*; D014981:Xenopus; D015044:Zona Pellucida / Q000502:physiology
D002457:Cell Extracts; D006657:Histones