Pluripotent stem cells could self-renew and differentiate into various cells. In particular, porcine pluripotent stem cells are useful for preclinical therapy, transgenic animals, and agricultural usage. These stem cells have naïve and primed pluripotent states. Naïve pluripotent stem cells represented by mouse embryonic stem cells form chimeras after blastocyst injection. Primed pluripotent stem cells represented by mouse epiblast stem cells and human embryonic stem cells. They could not produce chimeras after blastocyst injection. Populations of embryonic stem cells are not homogenous; therefore, reporter systems are used to clarify the status of stem cells and to isolate the cells. For this reason, studies of the OCT4 reporter system have been conducted for decades. This review will discuss the naïve and primed pluripotent states and recent progress in the development of porcine OCT4 reporter systems.

The transcription factor POU5F1, also known as OCT4 plays critical roles in maintaining pluripotency during early mammalian embryonic development and in embryonic stem cells. It is important to establish an OCT4 promoter region-based reporter system to study pluripotency. However, there is still a lack of information about the porcine OCT4 upstream region. To improve our understanding of the porcine OCT4 regulatory region, we identified conserved regions in the porcine OCT4 promoter upstream region by sequence-based comparative analysis using various mammalian genome sequences. The similarity of nucleotide sequences in the 5' upstream region was low among mammalian species. However, the OCT4 promoter and four regulatory regions, including distal and proximal enhancer elements, had high similarity. The putative transcription factor binding sites in the Oct4 5' upstream region nucleotide sequences from mice and pigs also differed. Some of these genes are related to pluripotency, and further research will allow us to better understand the differences in species-specific pluripotency. Next, a functional analysis of the porcine OCT4 promoter region was conducted. Luciferase reporter assay results indicated that the porcine OCT4 distal enhancer and proximal enhancer were highly activated in mouse embryonic stem cells and embryonic carcinoma cells, respectively. Similar to OCT4 upstream-based reporter systems derived from other species, the porcine OCT4 upstream region-based reporter constructs showed exclusive expression patterns depending on the state of pluripotency. This work provides basic information about the porcine OCT4 upstream region and various porcine OCT4 fluorescence reporter constructs, which can be applied to study species-specific pluripotency in early embryo development and the establishment of embryonic stem cells in pigs. This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (NRF-2017R1D1A1B03032256).

종자 건전성(seed health)은 종자 또는 식물체에 유익하지 못한 영향을 미칠 수 있는 생물체의 감염상태를 의미한다. 이들 생물체는 종자의 품질에 직접적인 피해를 줄 수 있으며,감염 종자는 식물체에 병을 유발하고 포장에서의 발병을 확산시킴으로써 대규모의 경제적 피해를 유발할 수 있다. 상업용종자의 해외증식 및 국제교역, 종자 유전자원의 해외분양 및 상호교환이 활발해짐에 따라 이러한 위험성이 더욱 커지고 있으며 더불어 종자 건전성 관리의 중요성 또한 증가하고 있다. 다양한 벼 종자 유전자원을 보존하고 연구용으로 분양하는 국제미작연구소(International Rice Research Institute, IRRI)는 유전자원의 건전성 확보를 위하여 종자건전성연구실(Seed health unit)을 두어 체계적인 관리시스템을 운영하고 있다. 필리핀 식물산업국 산하 식물검역소로부터 권한을 부여받아 필리핀 국내로 도입되거나 해외로 분양되는 유전자원에 대하여종자처리 및 건전성 모니터링, 종자 건전성 검사 및 데이터베이스 관리 업무를 수행하고 있다. 대상 병원균에 따라 육안검사, 수세현탁액 검사, 습지법 검사, 한천배지 검사 등을 적용하고 있으며, 감염종자는 온탕처리와 같은 물리적 처리와 살균제 또는 훈증제와 같은 화학적 처리를 수행한다. 국제미작연구소의 건전성 관리시스템을 우리나라 벼 종자 유전자원의보존·관리에 선별 적용하고, 더불어 종자소독방법과 저장 전관리체계를 확립함으로써 벼 유전자원의 품질을 제고할 수 있을 것이다. 또한 국제협력 및 공동연구 등 신뢰구축을 통해유용한 해외 유전자원을 확보하는 데 기여할 것으로 기대된다.