Research Assistant Professor Indiana University Indianapolis, Indiana, United States
Abstract Authors: Emanuele Pelosi1,2; Isaac Kyei-Barffour3; Sarah Williams4; Peter Koopman3.
1.Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
2.Centre for Clinical Research, The University of Queensland, Brisbane, QLD, Australia
3.Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
4.Queensland Cyber Infrastructure Foundation, Brisbane, QLD, Australia
Abstract Text: Müllerian anomalies (MAs) are anatomical variations of the female reproductive tract resulting from the incomplete development of the Müllerian ducts. MAs are complex gynecological birth defects occurring in 5.5% of the general female population and 8% of infertile women. In addition, MAs are diagnosed in 13.3% of women with miscarriages and 24.5% of those with miscarriages and infertility. Association with other several congenital malformations including renal, skeletal, and cardiovascular anomalies are common. Despite the immense impact on a woman’s health, the etiology of MAs remains largely unexplained.
WNT5A is a critical regulator of cell migration and polarity through the noncanonical Wnt pathway. Mutations of WNT5A have been associated with Robinow syndrome (OMIM 180700), which is characterized by skeletal and genital anomalies. The most commonly reported reproductive tract malformations in individuals with WNT5A mutations are genital hypoplasia and vaginal/cervical atresia. Studies in the mouse confirmed the requirement of Wnt5a for vaginal formation but analyses involving the upper reproductive tract are lacking.
Ablation of Wnt5a in the mouse results in severely hypoplastic uterine horns, suggesting that Wnt5a may have a broader involvement in Müllerian duct development. Wnt5a-/- uterine horns were more than 50% shorter than wild-type, showing a hypertrophic epithelial component while the stromal component was reduced in cellularity. To better understand the role of Wnt5a, we performed single-cell RNA-Sequencing (scRNA-Seq) of developing Müllerian ducts at 18.5 days post coitum (dpc). All identified cell clusters showed a similar cell composition between Wnt5a-/- and wild type Müllerian ducts, except for one cluster that was largely over-represented in Wnt5a-/- samples. To further understand the phenotype, we performed qPCR analysis and immunofluorescence staining, and found that the cranial portion of the uterine horns of Wnt5a-/- mice expressed markers of the fallopian tubes, suggesting a posterior to anterior homeotic transformation. Our results indicate additional roles for Wnt5a during mammalian reproductive development. These findings help to explain further the pathophysiology of Robinow syndrome and may prompt further investigations into the uterine anatomy of complex clinical cases.
