title: Comparative gene expression analysis of bovine nuclear-transferred embryos with different developmental potential by cDNA microarray and real-time PCR to determine genes that might reflect calf normality.
abstract: Placental abnormalities are the main factor in the high incidence of somatic cell clone abnormalities. The expression of several trophoblast cell-specific molecules is enhanced during gestational days 7 to 14. To determine the possible genes whose expression patterns might reflect calf normality, we first compared the gene expression profiles on day 15 between in vitro-fertilized (IVF) embryos and two types of somatic cell nuclear-transferred embryos with either a high (FNT) or low (CNT) incidence of neonatal abnormalities using a cDNA microarray containing 16 of 21 placenta-specific genes developed from tissues collected across gestation. To identify significant genes from the screening of day 15 embryos, genes with a less than two-fold difference in expression between IVF and CNT embryos, and those with a greater than two-fold difference between IVF and FNT and between CNT and FNT were considered to contribute to clone abnormalities. These two comparisons revealed 18 down-regulated and 18 upregulated genes of the 1722 genes examined. We then examined the expression levels of 10 genes with known functions in eight-cell and blastocyst-stage embryos by real-time PCR. The mRNA expression pattern of interferon (IFN)-tau, a trophectoderm-related gene, differed between IVF, CNT, and FNT eight-cell embryos; few or none of the IVF or CNT eight-cell embryos expressed IFN-tau mRNA, but all eight-cell FNT embryos expressed IFN-tau. IFN-tau mRNA expression was significantly higher in IVF blastocysts, however, than in nuclear-transferred blastocysts. Average IFN-tau mRNA expression in FNT blastocysts was not different from that in CNT blastocysts, due to one CNT blastocyst with high expression. The precise relation between early expression of IFN-tau mRNA and inferior developmental potential in cloned embryos should be examined further.
authors.affiliation: Laboratory of Animal Reproduction, College of Agriculture, Kinki University, Nara 631-8505, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kato
authors.forename: Xiangping
authors.initials: X
authors.lastname: Li
authors.forename: Dasari
authors.initials: D
authors.lastname: Amarnath
authors.forename: Koichi
authors.initials: K
authors.lastname: Ushizawa
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Hashizume
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Tokunaga
authors.forename: Masanori
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Tsunoda
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism; D002417:Cattle; D019976:Cloning, Organism / Q000379:methods*; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D053652:Nuclear Transfer Techniques; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary