Abstract
Objective:To explore the ability of diacyl glycerol (DAG) and inositol triphosphate (IP3), two major secondary messengers in the calcium signaling pathway, in activating oocytes.Material and Methods:Oocyte cumulus complex obtained from superovulated Swiss albino mice were incubated in M16 medium with liposome-encapsulated 1,2-Dipalmitoyl-sn-glycerol (LEDAG) and/or IP3 for 3 h. Strontium chloride was used as positive control. The activation potential, ploidy status, and blastocyst rate was calculated.Results:Both DAG and IP3, individually, induced activation in ~98% of oocytes, which was significantly higher (p<0.01) than activation induced by strontium chloride (60%). Delayed pronucleus formation and a higher percentage of diploid parthenotes was observed in oocytes activated with LEDAG and/or IP3. However, these embryos failed to progress beyond the 6-8–cell stage. Only when the medium was supplemented with LEDAG (5 μg/mL) and IP3 (10 μg/mL) could activated oocytes progress till the blastocyst stage (5.26%), which was lower than the blastocyst rate in the positive controls (13.91%).Conclusion:The results of the present study indicate that DAG and IP3 can induce delayed oocyte activation and poor development of parthenotes in vitro.
Highlights
Fertilization is a complex process which involves a series of well-defined morphologic and biochemical events in both spermatozoa and oocytes [1]
LEDAG and IP3 when used in combination, despite having no dose-dependent effect on activation, ~80-90% of oocytes were activated in all different combinations used (Figure 3)
Degeneration and fragmentation rate of oocytes activated with LEDAG and IP3: The degeneration and fragmentation rates were found as 5.13% and 9.2%, respectively, in the positive control group (Sr2Cl) (Table 1)
Summary
Fertilization is a complex process which involves a series of well-defined morphologic and biochemical events in both spermatozoa and oocytes [1]. The development of an embryo without the involvement of spermatozoa (paternal factors) is known as parthenogenesis. Parthenogenetic embryos play an important role in understanding the paternal and maternal contribution to the development of embryos, act as an alternative source of normally fertilized embryos for quality control experiments in assisted reproductive technology (ART) laboratories, and as a source of embryonic stem cells in the field of regenerative medicine. Even though artificial oocyte activation can be achieved in vitro using various physical, electrical, and chemical means [4,5,6], in vitro development of parthenotes is characterized by increased embryonic arrest, a high degree of fragmentation, developmental delay of embryos [7, 8], decreased blastocyst rate, and low cell number in blastocyst. The oocyte activation process and the subsequent development of parthenotes is driven by the calcium
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
