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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Livestock Bio-Systems » Research » Publications at this Location » Publication #369083

Research Project: Improving Lifetime Productivity in Swine

Location: Livestock Bio-Systems

Title: Epigenetic marks within the swine placenta are differentially expressed due to season

item CHEEK, ROBIN - Texas A&M University
item Rempel, Lea
item Miles, Jeremy

Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2020
Publication Date: 11/28/2020
Citation: Cheek, R., Rempel, L.A., Miles, J.R. 2020. Epigenetic marks within the swine placenta are differentially expressed due to season. Journal of Animal Science. 98(Supplement2):80.

Interpretive Summary:

Technical Abstract: The objective of the current project was to validate expression of known chromatin modification genes and assess downstream targets in d45 swine placenta derived from seasonal semen collections and breedings and semen storage. Six treatment groups were developed based upon; season of semen collection (cool or warm), storage of semen (cooled-extended or cryopreserved), and season of breeding (summer or winter) with 8 litters per group as follows: 1) cool/cooled-extended/winter, 2) cool/cryopreserved/winter, 3) warm/cryopreserved/winter, 4) warm/cooled-extended/summer, 5) warm/cooled-extended/summer, and 6) cool/cryopreserved/summer. RNA was extracted from the placenta of a small, medium, and large fetus from each litter, pooled by litter, reverse transcribed, and used for qPCR. Three genes; ATF2, ASH2L, and SMYD3, were validated. Downstream gene targets, ILIB and NANOG, were also tested. Interactions and main effects were tested using the mixed procedure of SAS with boar as a random effect. Placental ASH2L had a tendency for increased expression from summer breedings (P > 0.05), similar to previous findings using a different expression platform. Placental expression of ATF2 was greatest (P < 0.05) from placenta derived by summer breedings. A downstream target of ATF2, ILIB, had greater (P < 0.05) placental expression from summer breedings and semen that was cooled-extended as compared to cryopreserved (P < 0.05). Validation of placental expression of SMYD3 was greater from cooled-extended semen in contrast to cryopreserved semen (P < 0.05). These data were unexpected, as previously we determined a difference by breeding season only. However, NANOG, downstream of SMYD3, had greater placental expression from summer breedings (P < 0.05). The current study validated previous results indicating chromatin modification genes were primarily influenced predominantly by breeding season and to a lesser extent, semen storage techniques. Downstream targets were also influenced by breeding season likely influencing prenatal development. These data support epigenetic modifications persist, even though modern swine systems regulate and control temperature and lighting.