title: The endometrium responds differently to cloned versus fertilized embryos.
abstract: Although somatic cell nuclear transfer (SCNT) cloning is more efficient in cattle than in any other species tested so far, there is a high rate of pregnancy failure that has been linked to structural and functional abnormalities of the placenta. We tested the hypothesis that these changes may originate from disturbed embryo-maternal interactions in the peri-implantation period. Therefore, we evaluated the response of the endometrium to SCNT embryos (produced from 7 different fetal fibroblast cell lines) as compared with embryos derived from in vitro fertilization (IVF). SCNT embryos and IVF embryos were cultured under identical conditions to the blastocyst stage (day 7) and were transferred to corresponding recipients, which were slaughtered at day 18 of pregnancy. The mRNA profiles of endometrium samples were obtained using a custom cDNA microarray enriched for transcripts differentially expressed in the endometrium and/or oviduct epithelium during the estrous cycle and/or early pregnancy. Overall, the variation in mRNA profiles was greater in the SCNT group than in the IVF group. Furthermore, 58 transcripts were differentially abundant in endometria from SCNT and IVF pregnancies. Prominent examples are orphan nuclear receptor COUP-TFII and connexin 43, both known to play important roles in uterine receptivity and conceptus placentation. These findings suggest that placental failure in bovine clone pregnancies may originate from abnormal embryo-maternal communication that develops during the peri-implantation period. Endometrium transcriptome profiles may serve as a tool to evaluate SCNT embryos for their ability to establish pregnancy and develop a functional placenta.
authors.affiliation: Molecular Animal Breeding and Biotechnology, and Laboratory for Functional Genome Analysis, Gene Center, Ludwig-Maximilians-Universität München, 81377 Munich, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bauersachs
authors.forename: Susanne E
authors.initials: SE
authors.lastname: Ulbrich
authors.forename: Valeri
authors.initials: V
authors.lastname: Zakhartchenko
authors.forename: Megan
authors.initials: M
authors.lastname: Minten
authors.forename: Myriam
authors.initials: M
authors.lastname: Reichenbach
authors.forename: Horst-Dieter
authors.initials: HD
authors.lastname: Reichenbach
authors.forename: Helmut
authors.initials: H
authors.lastname: Blum
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Spencer
authors.forename: Eckhard
authors.initials: E
authors.lastname: Wolf
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D019976:Cloning, Organism; D004622:Embryo, Mammalian; D047108:Embryonic Development / Q000235:genetics; D004717:Endometrium / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D005347:Fibroblasts; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D053652:Nuclear Transfer Techniques; D010920:Placenta / Q000473:pathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000209:etiology*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger