title: Effect of the microenvironment and embryo density on developmental characteristics and gene expression profile of bovine preimplantative embryos cultured in vitro.
abstract: The Well of the Well (WOW) system has been developed to culture embryos in small groups or to track the development of single embryos. In the present study, we aimed to examine the effects of the microenvironment provided by the WOW system and embryo density on developmental rates, embryo quality and preimplantative gene expression profile of the resulting embryos. Embryos cultured in a group of 16 reached the blastocyst stage at a significantly lower level than zygotes cultured in a group of 50 (22.2 vs 30.3%), whereas zygotes cultured in WOW were able to compensate against low embryo densities, reaching a blastocyst rate as high as embryos cultured in a group of 50 (31.3 vs 30.3%). Moreover, embryos derived from WOW culture did not differ in terms of differential cell counts and apoptotic cell index compared with controls. The gene expression analysis revealed 62 transcripts to be upregulated and 33 transcripts to be downregulated by WOW culture. Comparing the in vivo derived blastocysts with the blastocysts derived from WOW culture, and group culture, expression of ATP5A1, PLAC8 and KRT8 was more similar to the embryos derived from WOW culture, whereas expression of S100A10 and ZP3 genes was more similar to blastocysts cultured in a group. In conclusion, microenvironment as well as embryo density significantly affected developmental rates. While subsequent blastocysts did not differ in terms of differential cell counts and apoptotic cell index, significant differences were observed in terms of the relative abundance of transcripts in the resulting embryos.
authors.affiliation: Animal Breeding and Husbandry Group, Insititute of Animal Science, University of Bonn, Bonn, Germany. michael.hoelker@itz.uni-bonn.de
authors.forename: Michael
authors.initials: M
authors.lastname: Hoelker
authors.forename: Franka
authors.initials: F
authors.lastname: Rings
authors.forename: Qamaruddin
authors.initials: Q
authors.lastname: Lund
authors.forename: Nasser
authors.initials: N
authors.lastname: Ghanem
authors.forename: Chirawath
authors.initials: C
authors.lastname: Phatsara
authors.forename: Josef
authors.initials: J
authors.lastname: Griese
authors.forename: Karl
authors.initials: K
authors.lastname: Schellander
authors.forename: Dawit
authors.initials: D
authors.lastname: Tesfaye
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D002417:Cattle; D002452:Cell Count; D003470:Culture Media; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D005307:Fertilization in Vitro; D015870:Gene Expression; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D014157:Transcription Factors / Q000235:genetics; D015053:Zygote / Q000254:growth & development / Q000378:metabolism
chemical_list: D003470:Culture Media; D014157:Transcription Factors