Reproduction Abstracts

Introduction: OCT4 has been known to master gene for maintaining pluripotency in mouse inner cell mass and embryonic stem cell. However, the variant of OCT4 was false-positively detected in somatic cells and this confuses the result in stem cell and embryo development research. So in this study, we aimed to identifying novel OCT4 variants in pig and examined their expression in various adult tissues.

Material and method: By comparing the sequence between human OCT4 variants and pig genome, the candidate OCT4 variant coding region was searched and the region was confirmed by RT-PCR in pooled in vitro fertilized blastocyst (n=10). The amplified porcine OCT4 variant region was sequenced. After identifying full sequence of porcine OCT4 variants, their expression was examined in following somatic tissues, liver, lung, kidney, spleen, muscle, heart, brain, testis, and ovary to confirm the possible relation between novel variant transcripts and pluripotency.

Result and discussion: Porcine OCT4 variant was expressed in blastocyst and their gne structures were similar to human OCT4 variant. Porcine OCT4B transcript contains differential N-terminal coding region, about 400bp upstream region of the second OCT4 exon, and OCT4B1 span cryptic exon which is normally the second intron of porcine OCT4A and OCT4B transcript. Porcine OCT4B transcript was expressed in somatic tissues like spleen and heart as well as testis and B1 form was only detected in testis. This result showed that the porcine OCT4 should be analyzed discriminatively considering the variant and OCT4B1 could be related to the pluripotency in pig.This research was supported by the Next BioGreen 21 program (PJ009493), Rural Development Administration, Republic of Korea.