Definition - What does Polar Body mean?
A polar body is a small cell that is formed at the same time an egg cell cycle that isn't used by the body, but it does contain half of the mother's genetic information and can be used to determine the genetic makeup of the egg cell. Researchers can examine the polar body and determine if the egg (that was formed at the same time) might have any genetic abnormalities. They can also determine, from the polar body, how viable an egg cell might be if used for in vitro fertilization (IVF).
FertilitySmarts explains Polar Body
Two polar bodies are usually made along with every egg cell. However, the vast majority of cell contents and nutrients are put into the egg rather than into the polar bodies, so that the egg can provide for itself should it be fertilized. Polar bodies contain a nucleus and very few other cell contents and will eventually disintegrate.
The egg and polar bodies were made from one original cell that completed all its day-to-day tasks by making proteins, and polar bodies contain a small amount of that protein-making genetic material. In a process called "polar body diagnosis," researchers can use this genetic material to work backward and determine the genetic makeup of the original cell and therefore the egg itself. Using this sort of reverse engineering, they can look for genetic abnormalities and, specifically, look for genes that affect the viability of the egg (or how likely it is to survive fertilization and implantation in the uterus). This can indicate which eggs are good to use for IVF and other fertility treatments. Only the mother’s genetic information can be determined; polar body diagnosis cannot determine the father’s genetic contribution.