title: Zygote arrest 1, nucleoplasmin 2, and developmentally associated protein 3 mRNA profiles throughout porcine embryo development in vitro.
abstract: Maternal effect genes (MEGs) are expressed in oocytes and embryos and play an important role in activation of the embryonic genome. An abnormality in the expression of these genes may lead to arrest of embryonic cleavage or to altered transcription of factors responsible for further embryonic development. In vitro-produced porcine embryos have a lower developmental potential than embryos produced in vivo. We hypothesized that in vitro embryo culture conditions have an effect on the expression of MEGs at various developmental stages, which may affect their developmental potential. Here, using real-time polymerase chain reaction, we examined mRNA profiles of the MEGs, zygote arrest 1 (ZAR-1), nucleoplasmin 2 (NPM2), and developmentally associated pluripotency protein 3 (DPPA3), in porcine oocytes and embryos produced in vitro and in vivo. Further, we evaluated the effect of the combined addition of EGF, interleukin 1β, and leukemia inhibitory factor to the porcine in vitro embryo production system on mRNA profiles of selected MEGs. Finally, we studied localization of the MEG protein products in in vitro-obtained oocytes and embryos using confocal microscopy. We found that the ZAR-1 mRNA profile differed throughout in vitro and in vivo embryo development. In the embryos produced in vitro, the decrease in ZAR-1 mRNA levels was observed at the 2-cell stage, whereas in in vivo embryos, ZAR-1 mRNA levels declined significantly starting at the 4-cell stage (P < 0.05). In vitro culture conditions affected transiently also DPPA3 mRNA levels at the 4-cell stage (P < 0.05). There was no difference in the NPM2 mRNA profile during in vitro and in vivo embryo development. The ZAR-1 and DPPA3 proteins were localized in the cytoplasm of the oocytes and embryos, whereas the NPM2 protein was found both in the cytoplasm and in the nucleus. All proteins were expressed until blastocyst stage. The addition of EGF and cytokines to the culture medium decreased DPPA3 mRNA levels in 8-cell embryos (P < 0.05). This study indicated that IVC conditions affect ZAR-1 mRNA levels before the 4-cell stage, which may disturb the activation of the embryonic genome in pigs. The expression of the proteins after the 4-cell to 8-cell transition indicates that these factors play a role beyond activation of the embryonic genome. Supplementation of the culture media with EGF and cytokines affects DPPA3 mRNA levels after maternal to embryonic transition.
authors: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland. Electronic address: m.wasielak@pan.olsztyn.pl.
authors: M
authors: M
authors: Wasielak
authors: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland.
authors: T
authors: T
authors: Więsak
authors: Department of Animal Physiology, University of Warmia and Mazury, Olsztyn, Poland.
authors: I
authors: I
authors: Bogacka
authors: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland.
authors: B Moza
authors: BM
authors: Jalali
authors: Department of Gamete and Embryo Biology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Olsztyn, Poland.
authors: M
authors: M
authors: Bogacki
mesh_terms: D000818:Animals; D004527:Egg Proteins / Q000235:genetics / Q000378:metabolism*; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000502:physiology*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D059471:In Vitro Oocyte Maturation Techniques; D053583:Interleukin-1beta / Q000494:pharmacology; D053605:Leukemia Inhibitory Factor / Q000494:pharmacology; D056489:Nucleoplasmins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D013552:Swine / Q000196:embryology*
chemical_list: D004527:Egg Proteins; D053583:Interleukin-1beta; D053605:Leukemia Inhibitory Factor; D056489:Nucleoplasmins; D012333:RNA, Messenger; D004815:Epidermal Growth Factor
keywords: Embryo; In vitro; Maternal effect gene; Oocyte; Pig