Perinuclear theca during spermatozoa maturation leading to fertilization

STAT (signal transducer and activator of transcription) proteins have been shown to be essential transcription factors which mediate biological effects of cytokines. Although most of the STATs have been shown to be widely expressed, Stat4 mRNA has been detected in only a few tissues, including the testis. In the present study, immunoblot analysis confirmed that the presence of Stat4 protein was similarly restricted, with the highest level observed in testis. In situ hybridization, immunoblot, and immunohistochemistry analyses revealed that in the testis, Stat4 was abundantly and exclusively expressed in male germ cells which have completed meiosis, at the round and elongating spermatid stages. Cytolocalization at various times of spermatid differentiation showed that the level of Stat4 protein increased in parallel in both cytoplasm and nuclei. No specific nuclear translocation that would have been an indicator of Stat4 activation was observed at any stage of spermatogenic differentiation. Interestingly, the Stat4 transcription factor was localized to the condensing perinuclear theca of spermatids, a localization that was confirmed by selective biochemical extraction of thecal proteins. Since the theca is known to depolymerize in the cytoplasm of the oocyte during the hours following fertilization, we hypothesized that sperm Stat4 would represent an original paternal contribution to the fertilized egg which may be involved in the onset of zygotic transcription.

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Glycerol decreases the integrity of the perinuclear theca in boar sperm

Zygote ◽

10.1017/s0967199411000785 ◽

2012 ◽

Vol 21 (2) ◽

pp. 172-177 ◽

Cited By ~ 2

Author(s):

Marco Antonio Arenas Núñez ◽

María de Lourdes Juárez-Mosqueda ◽

Oscar Gutiérrez-Pérez ◽

Santiago René Anzaldúa Arce ◽

Alejandro Córdova Izquierdo ◽

...

Keyword(s):

Electron Microscopy ◽

Adverse Effect ◽

Protease Inhibitors ◽

Free Group ◽

Glycerol Concentration ◽

Boar Sperm ◽

Perinuclear Theca ◽

First Time ◽

Control Samples

SummaryWe evaluated the effect of glycerol on the perinuclear theca (PT) of boar sperm. Samples from six ejaculates obtained from three different boars were incubated in the detergent Brij 36-T. Spermatozoa were treated with a glycerol concentration of either 2 or 4%, and incubated for 10 or 30 min; two other samples were treated with protease inhibitors (PI; leupeptin or an inhibitor commercial cocktail), mixed with 4% glycerol, and incubated for 30 min. A third glycerol-free group was used as the control. The samples were processed for electron microscopy evaluation. The PT remained intact in 78% of the control samples while, after addition of glycerol for 30 min, the proportion of spermatozoa with disrupted or absent PT increased (P < 0.05). PT was preserved in PI samples, but PT changes increased (P < 0.05). Differences due to treatment with glycerol (2 or 4%) at 10 or 30 min were not observed. These results show, to our knowledge for the first time, the adverse effect of glycerol on the integrity of the PT.

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