Effects of trehalose and sucrose on DNA integrity of evaporatively dried boar spermatozoa and embryo development after ICSI

Evaporative-drying, a novel technique for sperm preservation, has many advantages however, the results were inferior to freeze-drying. The objective of this study is to investigate the effects of trehalose or sucrose supplemented into desiccation/preservation solution for sperm dehydration on sperm DNA integrity and the development of porcine embryos after intracytoplasmic injected with evaporatively dried boar spermatozoa. The addition of 0.2 M trehalose or sucrose significantly reduced DNA damage of sperm compared to those of other concentrations. The rate of cleaved embryo and blastocyst formation was significantly increased in oocytes injected with evaporatively dried sperm with 0.2 M trehalose. According to TUNEL assay, total cell number was increased, and the indices of TUNEL, fragmentation and total apoptosis were significantly decreased in blastocysts from ICSI with sperm treated with trehalose. Also, evaporatively dried sperm with trehalsoe were preserved at 4°C for 1 year, and successfully produced pre-implantation embryos after ICSI that transferred to the recipients became pregnant and maintained pregnancy periods until 3 months. Consequently, the present study found out that trehalose could reduce DNA damage of sperm during dehydration, and oocytes injected with sperm treated with trehalose developed to pre-implantation embryos that might produce normal piglets after embryo transfer (ET).