title: Enhancement of maternal recognition of pregnancy with parthenogenetic embryos in bovine embryo transfer.
abstract: This study was performed to elucidate the changes in IFNT messenger RNA (mRNA) levels in in vivo-fertilized and parthenogenetic bovine embryos and their interferon-τ (IFNT) secretion amounts during the elongation phase. We assessed the induction capability of maternal recognition of pregnancy by parthenogenetic embryos and attempted cotransfer of in vivo-fertilized and parthenogenetic embryos. The expression level of IFNT mRNA in in vivo-fertilized embryos peaked on Day 18 after estrus, and the highest amount of uterine IFNT was observed on Day 20. Transfer of 10 parthenogenetic embryos produced a detectable amount of uterine IFNT. Transfer of one or three parthenogenetic embryos inhibited luteolysis. An increase in ISG15 mRNA levels in peripheral granulocytes was induced by the transfer of three parthenogenetic embryos. Cotransfer of three parthenogenetic embryos significantly improved the pregnancy rate on Day 40 in code 3 in vivo-fertilized embryos compared with single transfer without parthenogenetic embryos (65% vs. 35%). However, the pregnancy rate on Day 90 (35%) in cotransfer of code 3 in vivo-fertilized embryos did not differ from that upon single transfer (29%), because the cotransfer group had a higher incidence of pregnancy loss than with single transfer (47% vs. 17%) after Day 40. Cotransfer did not affect the pregnancy rate of code 2 in vivo-fertilized embryos. The incidence of pregnancy loss was higher in cotransfer of code 2 in vivo-fertilized embryos than in single transfer (30% vs. 7%). In conclusion, parthenogenetic embryos in the elongation phase secreted IFNT, enabling induction of maternal recognition of pregnancy. The present study revealed that enhancement of the maternal recognition of pregnancy using parthenogenetic embryos promoted the viability of poor-quality embryos until Day 40 of gestation. However, the incidence of pregnancy loss increased after Day 40 in the cotransfer of parthenogenetic embryos. A technique for promoting the full-term survival of poor-quality embryos is needed.
authors.affiliation: Animal Biotechnology Group, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, Japan. Electronic address: hirayama-hiroki@hro.or.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hirayama
authors.affiliation: Animal Biotechnology Group, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Moriyasu
authors.affiliation: Animal Biotechnology Group, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, Japan.
authors.forename: Soichi
authors.initials: S
authors.lastname: Kageyama
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Iwate University, Morioka, Iwate, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Sawai
authors.affiliation: Department of Animal Breeding and Reproduction, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Animal Breeding and Reproduction, NARO Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
authors.forename: Masaya
authors.initials: M
authors.lastname: Geshi
authors.affiliation: Animal Biotechnology Group, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Dairy Cow Group, Konsen Agricultural Experiment Station, Hokkaido Research Organization, Nakashibetsu, Hokkaido, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Koyama
authors.affiliation: Dairy Cow Group, Konsen Agricultural Experiment Station, Hokkaido Research Organization, Nakashibetsu, Hokkaido, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Koyama
authors.affiliation: Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Miyamoto
authors.affiliation: Division of Preventive Medicine, Department of Applied Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan.
authors.forename: Motozumi
authors.initials: M
authors.lastname: Matsui
authors.affiliation: Animal Biotechnology Group, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Minamihashi
mesh_terms: D000034:Abortion, Veterinary / Q000453:epidemiology; D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D002417:Cattle / Q000502:physiology*; D002418:Cattle Diseases / Q000453:epidemiology; D004624:Embryo Transfer / Q000379:methods / Q000662:veterinary*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D005865:Gestational Age; D007370:Interferon Type I / Q000032:analysis / Q000235:genetics / Q000502:physiology; D010312:Parthenogenesis; D011247:Pregnancy; D011255:Pregnancy Maintenance; D011257:Pregnancy Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D014599:Uterus / Q000737:chemistry
chemical_list: D007370:Interferon Type I; D011257:Pregnancy Proteins; D012333:RNA, Messenger; C020947:interferon tau
keywords: Bovine; Interferon tau; Interferon-stimulated gene; Parthenogenetic embryo; Poor-quality embryo; Pregnancy recognition