CONICET | Buscador de Institutos y Recursos Humanos

The acrosome reaction is part of the training that mammalian sperm must undergo in order to penetrate the female gamete. Previous authors have described differences in this process between different races as well as between bulls of the same race. The aim of this study is the evaluation of the acrosome reaction induced in vitro in samples of frozen semen of Spanish Retinta breed bulls, in three three predefined capacitation media. Frozen sperm samples from 8 bulls were thawed for 60 seconds at 37 degrees and selected by swim up in 1ml of Sp-TALP medium for one hour. 800 μl of the supernatant of each sample were extracted and separated into four 200 μl equal aliquots. The 4 resulting samples of each bull were cultured in a 5% CO2 humid incubator at 37ºC in 4 media: 1 ml of Sp-TALP plus 100ugrs/ml of heparin; 1ml of Sp-TALP plus 0,6% of BSA; 1 ml of Sp-TALP plus 100ugrs/ml and 0,6% of BSA and 1 ml of Sp-TALP as control. 100 μl samples were taken at 0 and 60 minutes. These samples were incubated for 10 min at 37ºC with FITC-PNA conjugated solution in H-TALP with 10mgr/ml of phenol red. Then, the samples were washed 2 times in PBS with 0.5 % of BSA an extended in glass slides. Air dried samples were mounted with cover slip with VectashieldTM and analyzed with an epifluorescence microscope. A count of 100 cells were performed in five extended slides of each sample, considering as reacted those cells with light red head and green intense acrosome. The non reacted cells showed only red color. Significant differences (P>0.01) were found between media and among bulls. There seems no great differences between different breeds in this three defined media, but some different between bulls has appeared. These data are consistent with other previously obtained by different authors in different bovine breeds.

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