Abstract
The actin nucleation factor Arp2/3 complex is a main regulator of actin assembly and is involved in multiple processes like cell migration and adhesion, endocytosis, and the establishment of cell polarity in mitosis. Our previous work showed that the Arp2/3 complex was involved in the actin-mediated mammalian oocyte asymmetric division. However, the regulatory mechanisms and signaling pathway of Arp2/3 complex in meiosis is still unclear. In the present work, we identified that the nucleation promoting factors (NPFs) JMY and WAVE2 were necessary for the expression and localization of Arp2/3 complex in mouse oocytes. RNAi of both caused the degradation of actin cap intensity, indicating the roles of NPFs in the formation of actin cap. Moreover, JMY and WAVE2 RNAi decreased the expression of ARP2, a key component of Arp2/3 complex. However, knock down of Arp2/3 complex by Arpc2 and Arpc3 siRNA microinjection did not affect the expression and localization of JMY and WAVE2. Our results indicate that the NPFs, JMY and WAVE2, are upstream regulators of Arp2/3 complex in mammalian oocyte asymmetric division.
Highlights
During mammalian oocyte meiotic maturation, a process called oocyte polarization occurs, which leads to a unique asymmetric division
We investigated the relationship between nucleation promoting factors (NPFs) and ARP2/3 complex during mouse oocyte meiotic maturation
By the knock down of JMY, WAVE2 and Arp2/3 complex, our results revealed that the NPFs JMY and WAVE2 were the upstream regulators of Arp2/3 complex in asymmetric mouse oocyte division
Summary
During mammalian oocyte meiotic maturation, a process called oocyte polarization occurs, which leads to a unique asymmetric division. The oocyte polarization experiences several steps including spindle migration, spindle anchoring and cortical reorganization [2] This series of oocyte polarization processes are controlled by microtubule and microfilament cytoskeletons [2,3]. Microfilaments are enriched to form an actin cap, microvilli are lost in the region overlaying the spindle, and cortical granules (CGs) are redistributed to form a CG-free domain (CGFD) [4,5,6]. All these processes are called cortical reorganization and polarization. The molecular details of oocyte polarization have not been completely understood
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
