You have accessJournal of UrologyInfertility: Basic Research & Pathophysiology1 Apr 2016MP70-06 A NOVEL TRANSCRIPTIONAL FACTOR NKAPL IS A GERM CELL-SPECIFIC SUPPRESSOR OF NOTCH SIGNALING AND MAY BE A CANDIDATE CAUSATIVE GENE OF COMPLETE MATURATION ARREST Yasushi Miyagawa, Hidenobu Okuda, Tetsuji Soda, Kentaro Takezawa, Shinichiro Fukuhara, Hiroshi Kiuchi, Akira Tsujimura, Masahito Ikawa, Hiromitsu Tanaka, and Norio Nonomura Yasushi MiyagawaYasushi Miyagawa More articles by this author , Hidenobu OkudaHidenobu Okuda More articles by this author , Tetsuji SodaTetsuji Soda More articles by this author , Kentaro TakezawaKentaro Takezawa More articles by this author , Shinichiro FukuharaShinichiro Fukuhara More articles by this author , Hiroshi KiuchiHiroshi Kiuchi More articles by this author , Akira TsujimuraAkira Tsujimura More articles by this author , Masahito IkawaMasahito Ikawa More articles by this author , Hiromitsu TanakaHiromitsu Tanaka More articles by this author , and Norio NonomuraNorio Nonomura More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.1431AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Spermatogenesis is an elaborately regulated system dedicated to the continuous production of spermatozoa via the genesis of spermatogonia. In this process, a variety of genes are expressed that are relevant to the differentiation of germ cells at each stage. Although Notch signaling plays a critical role in germ cell development in Drosophila and Caenorhabditis elegans, its function and importance for spermatogenesis in mammals is controversial. The objective of this study is to determine whether a novel germ cell-specific gene Nkapl is a functional nuclear protein as a repressor of Notch signaling in mice and an indispensable gene for spermatogenesis. METHODS To generate NKAPL targeting mouse, embryonic stem cell clone with Nkapl deletion was provided from the KOMP Repository (Project ID VG12856). These ES cells (C57/6N) were injected into blastocysts, and these blastocysts were transferred into the uteri of 2.5-dpc pseudopregnant ICR female mice. Mice with mutated alleles were isolated by PCR genotyping using specific primer sets. To examine the function of NKAPL in germ cells, GS cells were applied as an in vitro model. GS cells were derived from murine pup or adult testes. Their derivation provides us a unique method for studying functional analyses of germ cells (especially SSCs) and germ-cell-specific genes. GS cells constitutively overexpressing NKAPL (GS-Nkapl) were isolated by lentiviral induction of Nkapl to examine the effect of NKAPL for germ cells. RESULTS Nkapl was expressed robustly in spermatogonia and early spermatocytes after the age of 3 weeks. Nkapl-deleted mice showed complete arrest at the level of pachytene spermatocytes while no somatic phenotypic alteration was observed. In addition, apoptosis was observed in this cell type. Nkapl also associated with several molecules of the Notch corepressor complex such as CIR, HDAC3, and CSL. Overexpression of NKAPL in germline stem cells demonstrated that Nkapl induced changes in spermatogonial stem cell (SSC) markers and the reduction of differentiation factors through the Notch signaling pathway, whereas testes with Nkapl deleted showed inverse changes in those markers and factors. CONCLUSIONS Nkapl is indispensable because aberrantly elevated Notch signaling has negative effects on spermatogenesis, affecting SSC maintenance and differentiation factors. Notch signaling should be properly regulated through the transcriptional factor Nkapl and Nkapl may be a candidate causative gene of complete maturation arrest. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e907-e908 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Yasushi Miyagawa More articles by this author Hidenobu Okuda More articles by this author Tetsuji Soda More articles by this author Kentaro Takezawa More articles by this author Shinichiro Fukuhara More articles by this author Hiroshi Kiuchi More articles by this author Akira Tsujimura More articles by this author Masahito Ikawa More articles by this author Hiromitsu Tanaka More articles by this author Norio Nonomura More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...