Before reading this article, I had
a fair background on biogenetics from taking Honors Biology in ninth grade. More specifically, I understood the process meiosis, which is a specialized
cell division resulting in sex cells (sperm and eggs). Errors made during
meiosis may result in sex cells with the incorrect number of chromosomes. When
conception occurs and a fetus begins to form, the original sex cell with an incorrect
number of chromosomes will impact the fetus to have some sort of disorder. Individuals
with down syndrome are products of this mistake in meiosis because their
chromosome 21 has 3 replications instead of 2. I was also aware that as women
age, the risk of their child having complications such as down syndrome
increases dramatically.
However I didn’t
know that this phenomenon is referred to as the maternal age effect and results
in an increased risk of women having a fetus with an incorrect number of
chromosomes by 30% (“Down Syndrome,” 2014). Dartmouth University continued to
research this phenomenon in fruit flies and discovered that new protein
linkages come about in immature egg cells post DNA replication and that these
protein linkages are necessary for the cells’ sister chromatids to hold
together (“Down Syndrome,” 2014). In their research, they reduced the amount of
cohesion proteins after meiosis, which resulted in a loss of unity and
chromosomes becoming unnaturally unorganized during meiosis (“Down Syndrome,”
2014). This shows that the cohesion linkage proteins are necessary for the cell’s
proper division. In their continued research, they also discovered that once
they exposed the cells to aging, cohesion was lost and a rejuvenation process
in the fruit flies was unable to sustain it (“Down Syndrome,” 2014). Their
results raised the question that if human meiosis and linkage proteins function
the same way as fruit flies, does aging reduce the effectiveness of the rejuvenation
process as well because it simply can’t supply the linkage proteins at the same
rate as they are lost.
After reading this article, I hope
to learn more about meiosis and if there is a way to engineer replicates of the
cohesion linkage proteins to make up for the rejuvenation process’s inability
to sustain the proper amount to avoid errors in meiosis resulting in disorders
such as down syndrome.
Dartmouth College. (2014, September
11). Molecular mechanisms of birth defects among older women: Why older women
can have babies with Down Syndrome. ScienceDaily. Retrieved September 16, 2014
from www.sciencedaily.com/releases/2014/09/140911135440.htm
