During the process of oocyte maturation, asymmetric divisions result in segregation of the maternal genome and highly asymmetric partition of the cytoplasm, which generates the small polar body and the large oocyte. Why does the polar body stop cell division even after parthenogenetic activation?
It is because of the asymmetrical division of cytoplasm. Cytoplasm plays the most important role of development, having all the required precursors for division and development. Since polar body does not have the essential material to sustain development it is eventually degenerated.
Thanks Dr Maajid for the feedback. But, do you mean that if we move the PB into an enucleated oocyte it will develop and continue division?
Unfortunately but logically smart "Nature" favors one oocyte to be competent in cytoplasm point of view and give most of property property (cytoplasm) to one oocyte (to get fertilized and make baby) and leave other oocyte poor (called polar body destined to die)
Thanks Dr Subhash C. Juneja for the feedback. Indeed, science is the method for studying natural phenomena. When you look over the meiosis in spermatogonium and oocyte, the principle is the same and I guess the size of the polar body is similar to the spermatogonium. I am interested to know what is the fate of the polar body nuclear materials!
Certainly- sperms have to be in great number and they only need that much energy just to reach the oocyte. That is why spermatocyte produce more sperms by meiosis. The polar body DNA has to get degenerated otherwise additional DNA in oocyte can cause mutations
The nuclear material, yes! The polar body is the product of an uneven division. If I am thinking correctly, if you remove the nucleus of a GV and then somehow make it divide equally, you should be able to use both the equal portions as nuclear donor material.
It´s such an amazing question professor, well after fertilization the polar body divides in two polar bodies, so we can see three polar bodeis in the perivitelline space, after then it stops; would it be the absence of ribosomes?
Thanks Wasim Al Shebli for your feedback. You are right, ribosomes might play a role in this.
Thank you my dear professor, it's my pleasure to learn from you!
Best Regards...
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