Hsp70 has been identified in human (Miller et al., Hum Reprod 7:637, 1992) and bovine (Kamaruddin et al., Andrologia 36:327, 2004) ejaculates as well as in extracts from boar sperm (Huang et al., Anim Reprod Sci 63:231, 2000). The aim of this study was to determine Hsp 70 presence and distribution in ejaculated, capacitated and acrosome-reacted boar spermatozoa; the fate of this protein after fertilization was also studied. In fixed-permeabilized fresh semen 92.3±1.8% of cells showed a triangular-shaped immunoreactivity in the equatorial segment of the head. The localization of fluorescent signal underwent several rearrangements after capacitation, becoming particularly evident in the equatorial line in 72.6±5.3% of cells, and in a sub-equatorial band in 88.9±2.3% of sperm after induced acrosome reaction (AR). The proportion of unfixed cells showing the fluorescent signal significantly (P<0.05) increased after AR. No differences in Hsp70 amount between fresh, capacitated and reacted sperm were observed by Western blot. A loss of Hsp immunoreactivity in demembranated spermatozoa was recorded. Perivitelline sperm cells after IVF showed the same pattern as AR-induced cells; after sperm incorporation into the oocyte Hsp positivity became fuzzy and disappeared during sperm decondensation. Our results indicate that Hsp 70 undergoes a redistribution along sperm membrane and is probably translocated from the inner to the outer leaflet after capacitation and acrosome reaction.

IMMUNOLOCALIZATION OF HEAT SHOCK PROTEIN 70 (Hsp70) IN BOAR SPERMATOZOA

VOLPE, SARA;BERNARDINI, CHIARA;DE AMBROGI, MARCO;TAMANINI, CARLO;SEREN, ERALDO;GALEATI, GIOVANNA;SPINACI, MARCELLA
2005

Abstract

Hsp70 has been identified in human (Miller et al., Hum Reprod 7:637, 1992) and bovine (Kamaruddin et al., Andrologia 36:327, 2004) ejaculates as well as in extracts from boar sperm (Huang et al., Anim Reprod Sci 63:231, 2000). The aim of this study was to determine Hsp 70 presence and distribution in ejaculated, capacitated and acrosome-reacted boar spermatozoa; the fate of this protein after fertilization was also studied. In fixed-permeabilized fresh semen 92.3±1.8% of cells showed a triangular-shaped immunoreactivity in the equatorial segment of the head. The localization of fluorescent signal underwent several rearrangements after capacitation, becoming particularly evident in the equatorial line in 72.6±5.3% of cells, and in a sub-equatorial band in 88.9±2.3% of sperm after induced acrosome reaction (AR). The proportion of unfixed cells showing the fluorescent signal significantly (P<0.05) increased after AR. No differences in Hsp70 amount between fresh, capacitated and reacted sperm were observed by Western blot. A loss of Hsp immunoreactivity in demembranated spermatozoa was recorded. Perivitelline sperm cells after IVF showed the same pattern as AR-induced cells; after sperm incorporation into the oocyte Hsp positivity became fuzzy and disappeared during sperm decondensation. Our results indicate that Hsp 70 undergoes a redistribution along sperm membrane and is probably translocated from the inner to the outer leaflet after capacitation and acrosome reaction.
Abstracts- 9° ESDAR
377
377
Volpe S.; Bernardini C.; De Ambrogi M.; Tamanini C.; Seren E.; Galeati G.; Spinaci M.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/5999
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