Stage-specific Expression of Lanosterol 14-Demethylase in Mouse Oocytes in Relation to Fertilization and Embryo Development Competence |
Xiaoming Song, Hong Ouyang, Ping Tai, Xiufen Chen, Baoshan Xu, Jun Yan, Guoliang Xia, Meijia Zhang* |
|
Correspondence:
Meijia Zhang, |
|
|
|
Abstract |
Follicular fluid meiosis-activating sterol (FF-MAS) has been suggested as a positive factor which could improve the oocyte quality and subsequent embryo development after in vitro fertilization. However, FF-MAS is a highly lipophilic substance and is hard to detect in studying the relationship between MAS and quality of oocyte maturation. The present study focused on the expression of lanosterol 14-demethylase (LDM), a key enzyme that converts lanosterol to FF-MAS, on mouse oocyte maturation and its potency on development. LDM expression was strong in gonadotropin-primed germinal vesicle stage oocytes, weak after germinal vesicle breakdown (GVBD), and then strong in MII stage oocytes. The LDM-specific inhibitor azalanstat significantly inhibited oocyte fertilization (from 79.4% to 68.3%, p<0.05). Also, azalanstat (5 to 50 M) decreased the percentage of blastocyst development dose-dependently (from 78.7% to 23.4%, p<0.05). The specific inhibition of sterol ∆14-reductase and ∆7-reductase by AY9944 accumulates FF-MAS and could increase blastocyst development rates. Additionally, in the AY9944 group, the rate of inner cell mass (ICM)/ total cells was similar to that of in vivo development, but the rate was significantly decreased in azalanstat treatment. In conclusion, LDM, the key enzyme of FF-MAS production, may play an important role in fertilization and early development of the mouse embryo, especially in vitro. |
Keywords:
Mouse Oocyte; Lanosterol 14-Demethylase; In vitro Fertilization; Early Embryo Development |
|