Abstract
BackgroundBrucella is a zoonotic Gram-negative pathogen that causes abortion and infertility in ruminants and humans. TLR4 is the receptor for LPS which can recognize Brucella and initiate antigen-presenting cell activities that affect both innate and adaptive immunity. Consequently, transgenic sheep over-expressing TLR4 are an suitable model to investigate the effects of TLR4 on preventing Brucellosis. In this study, we generated transgenic sheep overexpressing TLR4 and aimed to evaluate the effects of different seasons (breeding and non-breeding season) on superovulation and the imported exogenous gene on growth.ResultsIn total of 43 donor ewes and 166 recipient ewes in breeding season, 37 donor ewes and 144 recipient ewes in non-breeding season were selected for super-ovulation and injected embryo transfer to generate transgenic sheep. Our results indicated the no. of embryos recovered of donors and the rate of pronuclear embryos did not show any significant difference between breeding and non-breeding seasons (P > 0.05). The positive rate of exogenous TLR4 tested were 21.21 % and 22.58 % in breeding and non-breeding season by Southern blot. The expression level of TLR4 in the transgenic sheep was 1.5 times higher than in the non-transgenic group (P < 0.05). The lambs overexpressing TLR4 had similar growth performance with non-transgenic lambs, and the blood physiological parameters of transgenic and non-transgenic were both in the normal range and did not show any difference.ConclusionsHere we establish an efficient platform for the production of transgenic sheep by the microinjection of pronuclear embryos during the whole year. The over-expression of TLR4 had no adverse effect on the growth of the sheep.
Highlights
Brucella is a zoonotic Gram-negative pathogen that causes abortion and infertility in ruminants and humans
Transgenic animals are produced by introducing exogenous DNA into the genetic material of pre-implantation embryos to enhance their usefulness to humans [1]
Our previous study produced TLR4 transgenic sheep and we found macrophage cells from TLR4 transgenic sheep showed a high resistance to LPS [12]
Summary
Brucella is a zoonotic Gram-negative pathogen that causes abortion and infertility in ruminants and humans. The production of the first transgenic sheep was reported in 1985 via microinjection of exogenous gene into the pronucleus [2]. Brucellosis is a world-wide zoonotic disease caused by Brucella spp., a Gram-negative facultative intracellular pathogen, leading to significant impact on public health and livestock industry. In domestic animals such as sheep and cattle, the outstanding manifestation of the pathology is abortion, stillbirth, orchitis, epididymitis, and infertility as a result of the colonization of placenta, fetal tissues and sexual organs [13]. There are no efficacious human vaccines available [17]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
