Robevska, G. | Search bioRxiv

bioRxiv2023

COUP-TFII regulates early bipotential gonad signaling and commitment to ovarian progenitors

The absence of expression of the Y-chromosome linked testis-determining gene SRY in early supporting gonadal cells (ESGC) of bipotential gonads leads to ovarian development. However, genetic variants in NR2F2/COUP-TFII represent a novel cause of SRY-negative 46,XX testicular/ovotesticular differences of sex development (T/OT-DSD). Thus, we hy-pothesized that COUP-TFII is part of the ovarian developmental network. We examined NR2F2/COUP-TFII expression and the genetic network under its regulation in human gonadal cells by analyzing single cell RNA-sequencing datasets of fetal gonads, differentiating induced pluripotent stem cells into bipotential gonad-like cells in vitro, and generating a NR2F2 knockout (KO) in the human granulosa-like cell line COV434. NR2F2 expression is highly upregulated during the bipotential gonad development, being detected in ESGCs. We identified that NR2F2 ablation in COV434 cells downregulated markers of ESGC and pre-granulosa cells, suggesting that COUP-TFII has a role in maintaining a multipotent state necessary for commitment to the ovarian development. We propose that impairment of COUP-TFII function may disrupt the transcriptional plasticity of ESGCs and instead drive them into commitment to the testicular pathway.

developmental biology↗

bioRxiv2022

Functional genomics analysis identifies impairment of HNF1B function as a cause of Mayer-Rokitansky-Küster-Hauser syndrome.

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome is a congenital condition characterized by aplasia or hypoplasia of the uterus and vagina in women with a typical 46,XX karyotype. This condition can occur as type I when isolated or as type II when associated with extragenital anomalies including kidney and skeletal abnormalities. The genetic basis of MRKH syndrome remains unexplained and several candidate genes have been proposed to play a role in its etiology, including HNF1B, LHX1, and WNT4. Here, we conducted a genomic analysis of 13 women affected by MRKH syndrome, resulting in the identification of candidate genes, including several novel candidates. We focused on HNF1B for further investigation due to its known association with, but unknown etiological role in, MRKH syndrome. We ablated Hnf1b specifically in the epithelium of the Mullerian ducts in mice, and found that this caused hypoplastic development of both the epithelial and stromal compartments of the uterus, as well as kidney anomalies, closely mirroring the MRKH type II phenotype. Using single-cell RNA sequencing of uterine tissue in the Hnf1b-ablated embryos, we analyzed the molecules and pathways downstream of Hnf1b, revealing a dysregulation of processes associated with cell proliferation, migration, and differentiation. Thus, we establish that loss of Hnf1b function leads to an MRKH phenotype, and generate the first mouse model of MRKH syndrome type II. Our results support the diagnostic value of HNF1B in clinical genetic testing for MRKH syndrome, and shed new light on the genetic causes of this poorly understood condition in womens reproductive health.

developmental biology↗