title: Effect of reproductive tract environment following controlled ovarian hyperstimulation treatment on embryo development and global transcriptome profile of blastocysts: implications for animal breeding and human assisted reproduction.
abstract: BACKGROUND
  In mammals, the reproductive tract plays a crucial role in the success of early reproductive events and provides an optimal microenvironment for early embryonic development. However, changes in the reproductive tract environment associated with controlled ovarian hyperstimulation and the influence on the embryo transcriptome profile have not been investigated. Therefore, we investigated differences in the development rate and the transcriptome profile of bovine blastocysts developing in the reproductive tract of unstimulated or superovulated heifers.
  
  
  METHODS
  Nineteen Simmental heifers were synchronized, superovulated and artificially inseminated; nine heifers were flushed on Day 2 after insemination and 2-4-cell stage embryos were recovered and endoscopicaly transferred to the ipsilateral oviduct of unstimulated (i.e. single-ovulating) synchronized recipients (n= 4 recipients; 25-50 embryos per recipient). The remaining 10 superovulated heifers and the unstimulated recipients were then non-surgically flushed on Day 7 to collect embryos. The blastocyst transcriptome profile was examined using the Affymetrix GeneChip Bovine Genome Array.
  
  
  RESULTS
  The proportion of embryos, which developed to the blastocyst stage, was lower in superovulated heifers than unstimulated heifers (P< 0.05). Blastocysts that developed under the abnormal endocrine conditions associated with ovulation induction showed higher cellular and metabolic activities, as genes involved in the oxidative phosphorylation pathway, different metabolic processes and translation and transcription processes, in addition to genes expressed in response to stress, were highly expressed compared with embryos that developed in the oviduct of unstimulated animals.
  
  
  CONCLUSIONS
  The environment in which the embryo develops in the oviduct/uterus significantly alters gene expression patterns, especially those genes that regulate metabolic activity in the embryo.
authors.affiliation: Department of Animal Breeding and Husbandry, University of Bonn, Bonn, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Gad
authors.forename: U
authors.initials: U
authors.lastname: Besenfelder
authors.forename: F
authors.initials: F
authors.lastname: Rings
authors.forename: N
authors.initials: N
authors.lastname: Ghanem
authors.forename: D
authors.initials: D
authors.lastname: Salilew-Wondim
authors.forename: M M
authors.initials: MM
authors.lastname: Hossain
authors.forename: D
authors.initials: D
authors.lastname: Tesfaye
authors.forename: P
authors.initials: P
authors.lastname: Lonergan
authors.forename: A
authors.initials: A
authors.lastname: Becker
authors.forename: U
authors.initials: U
authors.lastname: Cinar
authors.forename: K
authors.initials: K
authors.lastname: Schellander
authors.forename: V
authors.initials: V
authors.lastname: Havlicek
authors.forename: M
authors.initials: M
authors.lastname: Hölker
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism / Q000502:physiology*; D001947:Breeding; D002417:Cattle; D016000:Cluster Analysis; D004579:Electron Transport / Q000235:genetics; D014450:Electron Transport Complex III / Q000235:genetics / Q000378:metabolism; D004624:Embryo Transfer; D047108:Embryonic Development / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007315:Insemination, Artificial; D010057:Oviducts / Q000187:drug effects* / Q000378:metabolism; D010062:Ovulation Induction; D010085:Oxidative Phosphorylation; D011247:Pregnancy; D013480:Superovulation; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D014450:Electron Transport Complex III