Interleukin-6 supplementation improves post-transfer embryonic and fetal development of in vitro-produced bovine embryos.

Autor: Seekford ZK; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Wooldridge LK; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Dias NW; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Timlin CL; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Sales ÁF; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Speckhart SL; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Pohler KG; Department of Animal Sciences, Texas A&M University, College Station, TX, USA., Cockrum RR; Department of Dairy Science, Virginia Tech, Blacksburg, VA, USA., Mercadante VRG; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA., Ealy AD; Department of Animal & Poultry Sciences, Virginia Tech, Blacksburg, VA, USA. Electronic address: ealy@vt.edu.
Jazyk: angličtina
Zdroj: Theriogenology [Theriogenology] 2021 Aug; Vol. 170, pp. 15-22. Date of Electronic Publication: 2021 Apr 28.
DOI: 10.1016/j.theriogenology.2021.04.004
Abstrakt: The use of in vitro produced embryos in dairy and beef cattle has increased in recent years, but compromised post-transfer pregnancy success prevents producers from capturing all the benefits this technology can provide. This study explored whether supplementing interleukin-6 (IL6) during in vitro embryo development influences post-transfer development of the embryo-proper, fetus and placenta during early gestation in cattle. Slaughterhouse-derived cumulus oocyte complexes underwent IVM (day -1) and IVF (day 0). On day 5 post-fertilization, embryos were treated with either 0 (CONT) or 100 ng/mL recombinant bovine IL6. No difference in blastocyst formation was detected on day 7.5 post-fertilization, but an increase (P < 0.05) in inner cell mass cell numbers and tendency for increased (P = 0.08) trophectoderm cell numbers were detected in IL6-treated blastocysts. A subset of the blastocysts was loaded individually into transfer straws, and embryo transfer (ET) was completed using estrous cycle stage-matched, nonlactating commercial beef and dairy cows. A subset of cows from each group underwent timed artificial insemination (TAI). Pregnancy rates were similar among all three treatment groups at day 28 and 70. No differences in crown-rump length (CRL), crown nose length (CNL), abdominal diameter (AD), or placental fluid volume (PFV) were detected between TAI and ET-IL6 groups. Reductions (P < 0.05) in CRL and AD were detected at day 56 and a tendency for a reduction (P = 0.08) in PFV was detected on day 35 when comparing the ET-CONT group with the TAI group. Reductions (P < 0.05) in CRL and PFV on day 28 and CNL and AD on day 56 as well as a tendency for a reduction (P = 0.08) in PFV on day 35 were detected when contrasting ET-CONT with ET-IL6. Circulating plasma pregnancy-associated glycoprotein concentrations were similar among all treatment groups. In summary, IL6 treatment to IVP embryos before ET produced pregnancies that more closely resembled TAI-generated pregnancies than pregnancies generated using conventionally cultured embryos. These findings failed to find any adverse effects of IL6 supplementation on early development of the embryo-proper and fetus or on placental activity. Rather, these observations suggest that IL6 treatment may normalize the developmental trajectory of the embryo-proper and fetus for in vitro produced embryos.
Competing Interests: Declaration of competing interest None of the authors have any conflicts of interest to declare.
(Copyright © 2021 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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