Generation of induced spermatogonial stem cells by direct reprogramming

2014 Fiscal Year Final Research Report

• Project/Area Number: 25660255
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Integrative animal science
• Research Institution: Kitasato University
• Principal Investigator: Kubota Hiroshi 北里大学, 獣医学部, 教授 (80263094)
• Co-Investigator(Renkei-kenkyūsha): Kakiuchi Kazue 北里大学, 獣医学部, 助教 (90509184)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 幹細胞 / 分化・発生 / 生殖 / バイオテクノロジー

Outline of Final Research Achievements

Ectopic expression of Yamanaka factors (Oct3/4, Sox2, Klf4, c-Myc) in somatic cells has been shown to generate induced pluripotent stem cells (iPSCs), which are very similar to embryonic stem cells (ESCs), under ESC culture conditions. This study investigated whether somatic cells that were introduced Yamanaka factors can be reprogrammed into spermatogonial stem cells (SSCs) under SSC culture conditions. After introduction of expression plasmids for Yamanaka factors into male mouse embryonic fibroblasts (MEFs), they were cultured under ESC conditions or SSC conditions. Although iPSCs were generated in the ESC condition, neither SSC-like cells nor iPSCs were generated in SSC conditions. However, MEFs reprogrammed under the ESC condition followed by cultivation under the SSC condition generated undifferentiated cells with SSC characteristics, indicating the feasibility of generating induced SSCs.

Free Research Field

幹細胞生物学

Academic Significance and Societal Importance of the Research Achievements

精子の源となる精原幹細胞を人工多能性幹細胞（iPS細胞）のように体細胞から得ることができれば、優良個体や稀少動物種の繁殖に有用である。山中因子を導入して初期化した細胞を直接精原幹細胞の培養条件下で培養することにより精原幹細胞への分化誘導を試みたところ（ダイレクト・リプログラミング）、初期化の培養条件を検討することにより人工精原幹細胞の樹立の可能性が示唆された。本研究は新たな精子産生細胞の樹立に向けて重要な知見を示すものである。