A novel Amh-Treck transgenic mouse line allows toxin-dependent loss of supporting cells in gonads

Abstract

Cell ablation technology is useful for studying specific cell lineages in a developing organ in vivo. Herein, we established a novel anti-Mü llerian hormone (AMH)-toxin receptor-mediated cell knockout (Treck) mouse line, in which the diphtheria toxin (DT) receptor was specifically activated in Sertoli and granulosa cells in postnatal testes and ovaries respectively. In the postnatal testes of Amh-Treck transgenic (Tg) male mice, DT injection induced a specific loss of the Sertoli cells in a dose-dependent manner, as well as the specific degeneration of granulosa cells in the primary and secondary follicles caused by DT injection in Tg females. In the testes with depletion of Sertoli cell, germ cells appeared to survive for only several days after DT treatment and rapidly underwent cell degeneration, which led to the accumulation of a large amount of cell debris within the seminiferous tubules by day 10 after DT treatment. Transplantation of exogenous healthy Sertoli cells following DT treatment rescued the germ cell loss in the transplantation sites of the seminiferous epithelia, leading to a partial recovery of the spermatogenesis. These results provide not only in vivo evidence of the crucial role of Sertoli cells in the maintenance of germ cells, but also show that the Amh-Treck Tg line is a useful in vivo model of the function of the supporting cell lineage in developing mammalian gonads.

Cell‐specific ablation in the testis: what have we learned?

“…Shinomura and colleagues (Shinomura et al ., 2014) and our group (Rebourcet et al ., 2014b) have independently applied similar approaches to drive the expression of diphtheria toxin A specifically in Sertoli cells from foetal life onwards, inducing Sertoli cell ablation from embryonic day 15. In addition, we have also combined an Amh‐Cre line (Lecureuil et al ., 2002) and a iDTR line (Buch et al ., 2005) to permit ablation of Sertoli cells via injection of DTX (Rebourcet et al ., 2014a,b) (Fig.…”

“…The benefit of this inducible ablation model is that Sertoli cells can be ablated at different time points to assess temporal‐specific roles of this population not only in supporting testis development but also in adult function (Rebourcet et al ., 2014a). These studies have emphasised the fundamental importance of Sertoli cells, revealing many previously undocumented roles that the cells play in the control of testis development and function (Rebourcet et al ., 2014a,b; Shinomura et al ., 2014). …”

“…Injection of DTX leads to Sertoli cell death in the adult within 1 day and germ cell death follows rapidly, with no evidence of germ cells within the testis 10 days post DTX injection, including complete loss of mitotic spermatogonia (Rebourcet et al ., 2014a; Shinomura et al ., 2014). Only the reintroduction of immature Sertoli cells allows partial rescue of germ cell degeneration (Shinomura et al ., 2014). These data confirm the crucial role Sertoli cells play in the development and maintenance of the germ stem cell niche.…”

From Sex Determination to Initial Folliculogenesis in Mammalian Ovaries: Morphogenetic Waves along the Anteroposterior and Dorsoventral Axes

“…During primordial follicle formation, pre-granulosa cells of the medullary follicles are mitotically arrested in fetal stages and then, after birth, enter a mitotically active state [Mork et al, 2012], leading to AMH-positive granulosa cells of the medullary follicles during the initial wave of folliculogenesis [Münsterberg and Lovell-Badge, 1991;Lecureuil et al, 2002;Shinomura et al, 2014]. This suggests that release from mitotic arrest in pre-granulosa cells may be crucial for follicle assembly and the subsequent initial round of folliculogenesis in the medulla.…”

“…This would clarify the function and biological significance of SDSI-positive granulosa cells located in the medullary region, which contributes to the initial round of folliculogenesis in postnatal ovaries. We have developed an AMH-treck mouse line, which allows us to deplete AMH-positive follicles in neonatal ovaries by treatment with diphtheria toxin [Shinomura et al, 2014], leading to small aberrant ovaries with a drastic reduction in the 3β-HSD-positive interstitial region during the peripubertal stages. Further detailed analyses of the phenotypes of the ovaries missing the initial round of folliculogenesis should increase our understanding of the significance of the first wave of folliculogenesis from a reproductive biological aspect.…”