Effects of the TLR4 transgene on reproductive traits and DNA methylation pattern of oocytes in ewes

This study was conducted to systematically assess the reproductive performance of transgenic TLR4 ewes. In the TLR4 transgenic founders (F-0) and their positive offspring (F-1), hematological and reproductive parameters and the global DNA methylation level in oocytes at various stages were analyzed. The values of the physiological and biochemical parameters determined from the blood samples did not differ significantly between the transgenic and wild-type ewes. Moreover, the transgenic ewes showed reproductive traits similar to the wildtype ewes. These traits included characteristics of puberty, the estrus cycle, estrus duration, gestation, the pregnancy rate and the superovulation response. Additionally, no significant differences were found between transgenic and wild-type ewes in the DNA methylation level of the oocytes at various stages. In summary, the preliminary evidence presented in this paper demonstrates that the presence of the TLR4 transgene did not affect the reproductive performance in sheep.