title: The development and expression of pluripotency genes in embryos derived from nuclear transfer and in vitro fertilization.
abstract: Somatic cell nuclear transfer can be used to produce embryonic stem (ES) cells, cloned animals, and can even increase the population size of endangered animals. However, the application of this technique is limited by the low developmental rate of cloned embryos, a situation that may result from abnormal expression of some zygotic genes. In this study, sheep-sheep intra-species cloned embryos, goat-sheep inter-species cloned embryos, or sheep in vitro fertilized embryos were constructed and cultured in vitro and the developmental ability and expression of three pluripotency genes, SSEA-1, Nanog and Oct4, were examined. The results showed firstly that the developmental ability of in vitro fertilized embryos was significantly higher than that of cloned embryos. In addition, the percentage of intra-species cloned embryos that developed to morula or blastocyst stages was also significantly higher than that of the inter-species cloned embryos. Secondly, all three types of embryos expressed SSEA-1 at the 8-cell and morula stages. At the 8-cell stage, a higher percentage of in vitro fertilized embryos expressed SSEA-1 than occurred for cloned embryos. However, at the morula stage, all detected embryos could express SSEA-1. Thirdly, the three types of embryos expressed Oct4 mRNA at the morula and blastocyst stages, and embryos at the blastocyst stage expressed Nanog mRNA. The rate of expression of Oct4 and Nanog mRNA at these developmental stages was higher in in vitro fertilized embryos than in cloned embryos. These results indicated that, during early development, the failure to reactivate some pluripotency genes maybe is a reason for the low cloning efficiency found with cloned embryos.
authors.affiliation: School of Mathematics,Physics and Biological Engineering,Inner Mongolia University of Science & Technology,Aerding Avenue No. 7,Baotou,Inner Mongolia Autonomous Region 014010,China.
authors.forename: Li-Bing
authors.initials: LB
authors.lastname: Ma
authors.affiliation: School of Mathematics,Physics and Biological Engineering,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia,China.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: He
authors.affiliation: School of Farm and Garden Engineering,Baotou Light Industry Vocational Technical College,Baotou,Inner Mongolia,China.
authors.forename: Feng-Mei
authors.initials: FM
authors.lastname: Wang
authors.affiliation: College of Life Science,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia,China.
authors.forename: Jun-Wei
authors.initials: JW
authors.lastname: Cao
authors.affiliation: School of Mathematics,Physics and Biological Engineering,Inner Mongolia University of Science and Technology,Baotou,Inner Mongolia,China.
authors.forename: Teng
authors.initials: T
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D019976:Cloning, Organism; D046149:Embryo Culture Techniques; D005260:Female; D005307:Fertilization in Vitro; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics; D016256:Lewis X Antigen / Q000235:genetics; D009028:Morula / Q000502:physiology; D053652:Nuclear Transfer Techniques; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D012756:Sheep
chemical_list: D018398:Homeodomain Proteins; D016256:Lewis X Antigen; D050814:Octamer Transcription Factor-3