Biology/reproduction: polar body fertilization & development
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Question
Hi, I understand that during meiosis in a female produces a secondary oocyte and a polar body. The only difference between these two seem to be the amount of cytoplasm and organells, is this why when a polar body becomes fertalized it just becomes a clump of disorganized cells or is there an additional reason besides lack of cytoplasm and organells?
Dear Ami,
The answer to this question is still not completely known. Some preliminary studies have been done in mice, and at least one indicates that polar body chromosomes have the same genetic potential as oocyte chromosomes to participate in normal embryogenesis. Please see:
http://www.biolreprod.org/cgi/content/full/59/1/100
This suggests that it is something about the cytoplasm that does not permit the polar body to develop normally if it is fertilized. But this is an area of ongoing research, and the exact reasons for polar body inviability are not yet known.
Hope this helps.
Dana
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Answers by Expert:
Dana Krempels, Ph.D.
Expertise
I can answer biology-related questions in the areas of evolution, zoology, botany, genetics, and ecology. But I don't answer homework questions or provide ideas for your science fair projects. So students please do your learning the right way by reading your text assignments and studying!
Experience
At the University of Miami, I teach Evolution and Biodiversity, Botany, Zoology, Genetics, Ecology, and a variety of seminars (e.g., the Biology and Evolution of Human Gender Roles).
Education/Credentials
I have a B.S. in Biology and an A.B. in English from the University of Southern California (1980).
I earned my Ph.D. in Biology in the area of evolutionary biology/visual physiology from the University of Miami in 1989.
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I am currently an "expert" in both the "Rabbits" and "Wild Animals" categories.
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