The polar body is formed
during cell division of the immature egg cell called primary oocyte. During the
cell division, two cells are formed with equal distribution of the genetic
material in the nucleus, but in-equal distribution of the cytoplasm, the jelly-like
substance that surrounds the nucleus. Therefore, two dissimilar cells are
formed - the larger one is called the secondary oocyte, while the smaller cell
is called the primary polar body. Both cells undergo a further cell division,
the primary polar body divides into two polar bodies, while the secondary
oocyte gives rise to the mature egg or mature ovum and another polar body. Thus, during the process of formation of a
mature ovum from an immature egg, three polar bodies are formed
polar bodies are later destroyed and are therefore of no use to the body.
‘A new procedure could potentially double the number of eggs produced for in vitro fertilization.’
the use of polar bodies in the treatment of infertility
The research team took out the nucleus which contains the genetic material from
a donor oocyte and introduced the first polar body genome obtained from a
woman's developing oocyte.
To find out if the eggs were
functional, the researchers went to the extent of fertilizing the newly formed
oocytes with sperms. The eggs completed
their cell division following the fertilization, which resulted in the
formation of viable embryos.
However, they did not go beyond this point and
allow the embryos to develop into pregnancies.
The research is in its
very initial phase, but if it progresses in the right direction, it may be a
help to numerous women with infertility. Women
who are particularly likely to benefit from this treatment are those who wish
to get pregnant at an older age.
Older women experience reduced fertility. This process could double the number of
eggs produced for in vitro fertilization
, and therefore increase the chances of
having a baby.
treatment could also be potentially useful in those women who have serious
genetic diseases of the mitochondria that could interfere with the normal
development of the baby
Though it is a step forward in
the treatment of
, this technique can be put into use only after it
has been repeatedly tested and all the implications of the process have been understood.
- Ma H et al. Functional Human Oocytes Generated by
Transfer of Polar Body Genomes. DOI: - (http://dx.doi.org/10.1016/j.stem.2016.10.001)