Clarification about Oogenesis

[LightAtTheEnd]

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From Feralis's notes:

1. Oogenesis: being during embryonic development; oogonia (fetal cells) (mitosis) primary oocytes (meiosis) and remain at Prophase I until puberty (one primary oocyte during each menstrual cycle-28days, stim’d by FSH) continue its development through remainder of meiosis I within follicle (protects and nourishes oocyte) (completion of Meiosis I) secondary oocyte (most of cytoplasm)+ polar body (small cytoplasm; may or may not divide but products disintegrate) formed; now arrested at metaphase of meiosis II until ovulation

For the last part, shouldn't it say arrested at metaphase of meiosis II until fertilization, not ovulation?

 

[LightAtTheEnd]

anyone?

 

[TheEpicFruitCake]

Well this is weird... I could have sworn it should be fertilization, but I'm staring at my Campbell book 2013 edition and it says "Ovulation, sperm entry"

Alright, I pulled out Campbell 9th edition. It says the exact same thing LMAO. I guess we are wrong?

 

[swindoll]

I thought that meiosis 2 BEGINS after fertilization.. But that doesn't line up with ferallis notes either... I need to review this also.

 

[TheEpicFruitCake]

I think I understand. TECHNICALLY it's correct. Meiosis II is stopped before ovulation.

So it goes Primordial germ cell mitosis > Oogonium Mitosis > Primary oocyte Meiosis I and Metaphase II > Secondary Oocyte > Ovulation > fertilization > completion of meiosis II

Fertilization can't happen until ovulation so... yeah haha

 

[LightAtTheEnd]

Oh ok. I think I kinda get what you're saying.. that the secondary oocyte is arrested in metaphase II until ovulation + fertilization. The word "until" implies that after ovulation it changes from metaphase II to something else, I guess that's why it's confusing.

But you didnt mention prophase I!

Germ cell > mitosis > primary oocyte arrested in prophase I > puberty > secondary oocyte arrested in metaphase II > ovulation + fertilization > completion of meiosis II

 

[TheEpicFruitCake]

^^^ My man/woman haha. Thanks, I actually had forgotten that completely!