Journal of Animal Science and Technology
Korean Society of Animal Science and Technology
Article

Rapamycin Treatment During Prolonged In Vitro Maturation Enhances the Developmental Competence of Immature Porcine Oocytes

Seung-Eun Lee1,2, Han-Bi Lee1,2, Jae-Wook Yoon1, Hyo-Jin Park1, So-Hee Kim1, Dong-Hun Han1,2, Eun-Seo Lim1,2, Eun-Young Kim1,2,3, Se-Pill Park1,2,4,*
1Stem Cell Research Center, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea.
2Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea.
3Mirae Cell Bio, 1502 isbiz-tower 147, Seongsui-ro, Seongdong-gu, Seoul 04795, Korea.
4Department of Bio Medical Informatic, College of Applied Life Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea.
*Corresponding Author: Se-Pill Park, Stem Cell Research Center, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea, Republic of. Faculty of Biotechnology, College of Applied Life Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea, Republic of. Department of Bio Medical Informatic, College of Applied Life Sciences, Jeju National University, 102 Jejudaehak-ro, Jeju-si, Jeju-do 63243, Korea, Republic of. E-mail: sppark@jejunu.ac.kr.

© Copyright 2023 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Jul 25, 2023; Revised: Aug 25, 2023; Accepted: Sep 23, 2023

Published Online: Sep 25, 2023

Abstract

Porcine oocytes undergo <italic>in vitro</italic> maturation (IVM) for 42–44 h. During this period, most oocytes proceed to metaphase and then to pro-metaphase if the nucleus has sufficiently matured. Forty-four hours is sufficient for oocyte nuclear maturation but not for full maturation of the oocyte cytoplasm. This study investigated the influences of extension of the IVM duration with rapamycin treatment on molecular maturation factors. The phospho-p44/42 mitogen-activated protein kinase (MAPK) level was enhanced in comparison with the total p44/42 MAPK level after 52 h of IVM. Oocytes were treated with and without 10 μM rapamycin (10 R and 0 R, respectively) and examined after 52 h of IVM, whereas control oocytes were examined after 44 h of IVM. Phospho-p44/42 MAPK activity was upregulated the 10 R and 0 R oocytes than in control oocytes. The expression levels of maternal genes were highest in 10 R oocytes and were higher in 0 R oocytes than in control oocytes. Reactive oxygen species (ROS) activity was dramatically increased in 0 R oocytes but was similar in 10 R and control oocytes. The 10 R group exhibited an increased embryo development rate, a higher total cell number per blastocyst, and decreased DNA fragmentation. The mRNA level of development-related (<italic>POU5F1 </italic>and<italic> NANOG) </italic>mRNA<italic>, </italic>oocyte-apoptotic (<italic>BCL2L1) </italic>genes were highest in 10 R blastocysts. These results suggest that prolonged IVM duration with rapamycin treatment represses ROS production and increases expression of molecular maturation factors. Therefore, this is a good strategy to enhance the developmental capacity in porcine oocytes.

Keywords: IVM extension; Rapamycin; Molecular maturation factors; ROS; Porcine oocyte