A Wt1-Dmrt1 Transgene Restores DMRT1 to Sertoli Cells of Dmrt1−/− Testes: A Novel Model of DMRT1-Deficient Germ Cells1

Abstract

DMRT1 is an evolutionarily conserved transcriptional factor expressed only in the postnatal testis, where it is produced in Sertoli cells and germ cells. While deletion of Dmrt1 in mice demonstrated it is required for postnatal testis development and fertility, much is still unknown about its temporal- and cell-specific functions. This study characterized a novel mouse model of DMRT1-deficient germ cells that was generated by breeding Dmrt1-null (Dmrt1(-/-)) mice with Wt1-Dmrt1 transgenic (Dmrt1(+/-;tg)) mice, which express a rat Dmrt1 cDNA in gonadal supporting cells by directing it from the Wilms tumor 1 locus in a yeast artificial chromosome transgene. Like Dmrt1(-/-) mice, male Dmrt1(-/-) transgenic mice (Dmrt1(-/-;tg)) were infertile, while female mice were fertile. Immunohistochemistry and Western blot analysis showed transgenic DMRT1 expressed in supporting cells of the newborn gonads of both sex and in Sertoli cells of the testis afterbirth. Sertoli cells were evaluated by electron microscopy, revealing that maturation of Dmrt1(-/-;tg) Sertoli cells was incomplete. Morphological analysis of testes from 42-day-old mice showed that, compared to Dmrt1(-/-) mice, Dmrt1(-/-;tg) mice have improved seminiferous tubule structure, with lumens present in many. Immunohistochemistry of the polarity markers ESPIN and NECTIN-2 showed that DMRT1 in Sertoli cells is required for NECTIN-2 expression and influences organization of ectoplasmic specializations. Further functional analyses of the transgene on a Dmrt1(-/-) background showed that it did not rescue the decrease in Dmrt1(-/-) testis size, but when expressed on a wild-type background, exogenous DMRT1 prevented the normal age-related decline in testis size and enhanced sperm progressive motility. The studies suggest that DMRT1 in Sertoli cells regulates tubule morphology, spermatogenesis, and sperm function via its effects on Sertoli cell maturation and polarity. Furthermore, expression and function of transgenic DMRT1 in Sertoli cells establishes a novel mouse model of DMRT1-deficient germ cells generated by breeding Dmrt1-null mice with Wt1-Dmrt1 transgenic mice (rescue; Dmrt1(-/-;tg)).

Female-to-male sex reversal in mice caused by transgenic overexpression of Dmrt1

“…4). The emergence of SRY in the common progenitor of marsupial and placental mammals has rendered Dmrt1 redundant, such that the regulatory elements required for sufficient expression in the supporting cell lineage (Lei et al, 2007;Agbor et al, 2013) were lost or degraded.…”

“…3M-O,V; data not shown). Accordingly, several known DMRT1 targets, such as Espn, Cst9, Etd and Vsig1 (Murphy et al, 2010;Agbor et al, 2013), were massively upregulated in XX transgenic testes (supplementary material Fig. S3G-J).…”

The regulatory repertoire of PLZF and SALL4 in undifferentiated spermatogonia

“…Indeed, SSC transplantation combined with cell sorting, in vitro gene knockdown, and gene knockout approaches have enabled systematic characterization of the phenotype of mouse SSCs (Aloisio et al, 2014;Buaas et al, 2004;Buageaw et al, 2005;Chan et al, 2014;Costoya et al, 2004;Kanatsu-Shinohara et al, 2014Kubota et al, 2003;Oatley et al, 2011;Shinohara et al, 1999Shinohara et al, , 2000Tokuda et al, 2007;Yang et al, 2013a,b). Moreover, gene knockout studies have been used extensively to demonstrate loss of spermatogenesis following loss of specific gene products and have often been coupled with lineage tracing to demonstrate expression of gene products in SSCs in vivo (Agbor et al, 2013;Aloisio et al, 2014;Ballow et al, 2006;Buaas et al, 2004;Costoya et al, 2004;Falender et al, 2005;Goertz et al, 2011;Greenbaum et al, 2006;Hobbs et al, 2012;Hu et al, 2013;Kanatsu-Shinohara et al, 2014;Lovasco et al, 2015;Meng et al, 2000;Nakagawa et al, 2007;Oatley et al, 2011;Raverot et al, 2005;Schlesser et al, 2008;Suzuki et al, 2012;Yang et al, 2013a;Yoshida et al, 2007Yoshida et al, , 2004. A majority of the gene products examined that are required for undifferentiated spermatogonial function are involved in transcriptional regulation [e.g.…”

Expression characterization of testicular DMRT1 in both Sertoli cells and spermatogenic cells of polyploid gibel carp

“…In mammals, DMRT1 was found to be expressed both in Sertoli cells and in germ cells (Lei et al, 2007). Moreover, it was indicated that DMRT1 in Sertoli cells was essential to maintain testis determination (Matson et al, 2011) and regulate tubule morphology, spermatogenesis, and sperm function in mammals (Agbor et al, 2013). Additionally, DMRT1 in spermatogonia was demonstrated to determine whether spermatogonia undergo mitosis and spermatogonial differentiation or meiosis (Matson et al, 2010).…”