Cell adhesion molecules expression pattern indicates that somatic cells arbitrate gonadal sex of differentiating bipotential fetal mouse gonad

Abstract

Unlike other organ anlagens, the primordial gonad is sexually bipotential in all animals. In mouse, the bipotential gonad differentiates into testis or ovary depending on the genetic sex (XY or XX) of the fetus. During gonad development cells segregate, depending on genetic sex, into distinct compartments: testis cords and interstitium form in XY gonad, and germ cell cysts and stroma in XX gonad. However, our knowledge of mechanisms governing gonadal sex differentiation remains very vague. Because it is known that adhesion molecules (CAMs) play a key role in organogenesis, we suspected that diversified expression of CAMs should also play a crucial role in gonad development. Using microarray analysis we identified 129 CAMs and factors regulating cell adhesion during sexual differentiation of mouse gonad. To identify genes expressed differentially in three cell lines in XY and XX gonads: i) supporting (Sertoli or follicular cells), ii) interstitial or stromal cells, and iii) germ cells, we used transgenic mice expressing EGFP reporter gene and FACS cell sorting. Although a large number of CAMs expressed ubiquitously, expression of certain genes was cell line- and genetic sex-specific. The sets of CAMs differentially expressed in supporting versus interstitial/stromal cells may be responsible for segregation of these two cell lines during gonadal development. There was also a significant difference in CAMs expression pattern between XY supporting (Sertoli) and XX supporting (follicular) cells but not between XY and XX germ cells. This indicates that differential CAMs expression pattern in the somatic cells but not in the germ line arbitrates structural organization of gonadal anlagen into testis or ovary.

N-Cadherin Is Critical for the Survival of Germ Cells, the Formation of Steroidogenic Cells, and the Architecture of Developing Mouse Gonads

“…This specific cell adhesion signature allows cells to recognize and adhere to each other. We demonstrated previously that CAMs are important for gonad differentiation, and that homologous cell types of different sexes differ in their CAM signature [4]. Additionally, we showed that the knockout of E-cadherin in the somatic or germ cells of developing gonads leads to germ cell loss [5].…”

Expression of primary cilia-related genes in developing mouse gonads

“…described (Piprek et al, 2017). All individuals were genotyped to define sex and the presence of transgene as previously described (Piprek et al, 2017). The gonads from mouse fetuses were pooled accordingly to the sex and developmental stage.…”

“…The gonads from mouse fetuses were pooled accordingly to the sex and developmental stage. The gonads were incubated in 250 ml 0.25% Trypsin-EDTA (Sigma, #T4049) at 37°C for 5-10 minutes (Piprek et al, 2017). After tissue dissociation, the enzyme solution was replaced with PBS.…”

“…Pooled gonads from 5 fetuses were used for each time point and experiments were repeated three times. Fluorescence-activated cell sorting (FACS) was used to segregate three cell types isolated from the gonads (Piprek et al, 2017). Total RNA was isolated from each cell type and analyzed using microarray technique as previously described (Piprek et al, 2017).…”

Matrix metalloproteinase-dependent regulation of extracellular matrix shapes the structure of sexually differentiating mouse gonads

“…Later in development, the 96 ovigerous cords split into ovarian follicles (Pepling and Spradling, 2001;Pepling et al, 2010). 97It has been shown that in mouse, rat, cattle, chicken, slider (Trachemys scripta) and the 98 African clawed frog (Xenopus laevis) (Paranko et al, 1983;Yao et al, 2004; Hummitzsch et 99 al., 2013;Piprek et al, 2017aPiprek et al, ,2018 the ECM plays important role in gonad development. The 100 ECM contains many different proteins including collagens, laminins, fibronectin, and 101 proteoglycans (reviewed by Yue, 2014).…”