CXCR3 participates in asymmetric division of mouse oocytes by modulating actin dynamics

Extensive research has been conducted on the role of CXCR3 in immune responses and inflammation. However, the role of CXCR3 in the reproductive system, particularly in oocyte development, remains unknown. In this study, we present findings on the involvement of CXCR3 in the meiotic division process of mouse oocytes. We found CXCR3 was expressed consistently throughout the entire maturation process of mouse oocyte. Inhibition of CXCR3 impaired the asymmetric division of oocyte, while the injection of Cxcr3 mRNA was capable of restoring these defects. Further study showed that inhibition of CXCR3 perturbed spindle migration by affecting LIMK/cofilin pathway-mediated actin remodeling. Knockout of CXCR3 led to an upregulation of actin-binding protein and an increased ATP level in GV-stage oocytes, while maintaining normal actin dynamics during the process of meiosis. Additionally, we noticed the expression level of DYNLT1 is markedly elevated in CXCR3-null oocytes. DYNLT1 bound with the Arp2/3 complex, and knockdown of DYNLT1 in CXCR3-null oocytes impaired the organization of cytoplasmic actin, suggesting the regulatory role of DYNLT1 in actin organization, and the compensatory expression of DYNLT1 may contribute to maintain normal actin dynamics in CXCR3-knockout oocytes. In summary, our findings provide insights into the intricate network of actin dynamics associated with CXCR3 during oocyte meiosis.