Placenta is the main nutrition source for the fetus during pregnancy. Thus, it has a pivotal function in the pregnant process. Many functions of the placenta have been elucidated. An abnormal placenta is associated with a high rate of pregnancy failure in somatic cloned bovine. Differentially expressed genes (DEGs) were examined in a comparison between normal and cloned bovine placenta using annealing control primer (ACP)-based GeneFishing PCR. Using 120 ACPs, nearly 80 genes were identified and the fragments of 42 DEGs were sequenced. 38 of these genes were known genes and four were unknown. To determine the DEGs result, six target clones expressing on one-side of a normal and a clone placenta were selected. Through an analysis of the target genes using the real-time PCR, the expressing pattern was found to be somewhat different from the DEGs. Additionally, several genes appeared with the same expression pattern. Taken together, this suggests that the target genes would be essential for research into what influences the placental formative mechanisms during fetal development.

This study was conducted to investigate the specific expression genes in the cloned bovine tissues. Donor cells, cloned tissues were analysed by RAPD-RFLP method. The results were detected three genes (CH-U7B, CH-U7M and CH-U7P) in the cloned fetus. It was found a single copy genes by southern hybridization. Sequence analysis of CH-U7M gene was shown 99% homology to a previously reported EST from a cloned bovine fetus. The putative ORF was encode a protein of hydrophobicity index 0.03. Semi-quantitative RT-PCR by using the CH-LS001 specific primer was remarkably detected in the lung tissue of cloned fetus. Further investigation of these genes may provide one of the key information to explain the early death, abnormal fetus, large off-spring and the low pregnancy rate in the production of cloned bovine.