Is there a centrosome in a human egg cell? Is the reason why the egg cell remains paused before meiosis 2 because there isn't a centrosome, and it only divides when the sperm fertilizes it thus it can have a centrosome? If this is so, then how did oogenesis happen? ?


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To answer the first part of your question. The sperm actually introduces two centrosomes. The centrosome then nucleates the new microtubule assembly to form the sperm aster — a step essential for successful fertilization. You can visit these sites Simerly, et al as well as Paweltz, et al

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    $\begingroup$ Could you provide a more recent reference? (The ones you provided are from 1995 and 1987). I ask because From Zero to Many: Control of Centriole Number in Development and Disease (2009) says: "Notably, oocytes and spermatozoa lose parts of the centrosome in a complementary manner. Centrioles, but not centrosome proteins, are lost in the oocyte. On the other hand, in sperm, the PCM material is lost, but not the centriole/basal body, which is necessary for flagella formation. ... $\endgroup$ Aug 11, 2019 at 13:54
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    $\begingroup$ ... Fertilization brings together the basal body from the sperm, which becomes a centriole within the zygote, and the PCM from the egg." $\endgroup$ Aug 11, 2019 at 13:54

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