The self-renewal capacity of the stem cell pool determines tissue function and health. Cadherin-22 (Cdh22), a member of the cadherin superfamily, has two splicing patterns in rats, and the short type that lacks a catenin binding domain is closely related to spermatogonial stem cell self-renewal. Previously, we reported that CDH22 was highly expressed in mouse ovary germ cells, especially in female germ line stem cells (FGSCs). However, its underlying function in FGSCs is still not clear. Here, we found that Cdh22 encodes only one type of protein product in mice and demonstrated that CDH22 was required for FGSC self-renewal. In addition, JAK2 and β-catenin were found to interact with CDH22 and be involved in CDH22 signaling in mouse FGSCs. Moreover, extrinsic CDH22 was identified as a potential molecule that participates in FGSC adhesion and is pivotal for FGSC maintenance and self-renewal. These results reveal that CDH22 functions as an essential molecule in FGSC maintenance and self-renewal via different mechanisms, including interaction with the JAK-STAT signaling pathway and β-catenin.
Keywords: Alternative splicing; Apoptosis; Cell proliferation; Co-culture; Molecular interaction; Niche.