Profilin 1 在小鼠卵子中通过反馈的方式调节由微丝介导的极体排出

Mammalian oocytes undergo several crucial processes during meiosis maturation, including spindle formation and migration and polar body extrusion, which rely on the regulation of actin. As a small actin-binding protein, profilin 1 plays a central role in the regulation of actin assembly. However, the functions of profilin 1 in mammalian oocytes are uncertain. To investigate the function of profilin 1 in oocytes, immunofluorescent staining was first used to examine the localization of profilin 1. The results showed that profilin 1 was localized around the meiotic spindles and was co-localized with cytoplasmic actin. Knockdown (KD) of profilin 1 with specific morpholino (MO) microinjection resulted in polar body extrusion failure. This failure was resulted from an increase of actin expression both at membranes and in the cytoplasm. Furthermore, western blot analysis revealed that the expression of ROCK and the phosphorylation level of myosin light chain (MLC) were significantly decreased after profilin 1 KD. Thus, our results indicated that a feedback mechanism between profilin-actin (PA) and ROCK-MLC2 regulates the actin assembly during mouse oocyte maturation.