<div>Background: Streptolysin O (SLO), a pore-forming protein in plasma membrane (PM), has been used to internalize a variety of molecules (DNA and RNA) in cells. In sperm, however, SLO has only been used to release acrosomal contents. Its possible use as biotechnology in the cryopreservation of pig semen. However, porcine sperm are very sensitive to the freeze-thaw process. The study aimed to evaluate the pore formation in the PM, the addition of trehalose and the post cryopreservation viability of porcine spermatozoa using SLO. 
 
Methods: Research period was spring 2017- summer 2018. Thirty ejaculates from five mature boars were used. Semen was incubated in SLO 0.6 IU/ml and trehalose (added at 100, 200 and 400 &igrave;M). Semen diluted in commercial diluent as control group. Presence of pores was checked by scanning electronic microscopy. To evaluate sperm membrane integrity and functional status the Coomassie stain with HOST test and the Chlortetracycline test were used.&nbsp; 
 
Result: It was found that SLO could form pores in the sperm cell membrane The addiction of 200 &igrave;M trehalose to the freezing medium have different effects on the quality of boar sperm, showing highest motility and viability during the cooling process.</div>

Pores Formation in Porcine Sperm Incubated in Streptolysin O and Its Post Thawing Viability after Trehalose Treatment