Tuesday, September 16, 2014

Molecular Mechanisms of the Maternal Age Effect and how it can cause Down Syndrome

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

3 comments:

  1. I find the idea of the maternal age effect very interesting. I know that as women age and become pregnant at an older age they have a greater and greater chance of having a child with a disorder such as Down Syndrome. These women have a greater chance of their babies having a mutated, missing, or extra chromosome causing a disorder. I personally found it very interesting to learn that these disorders are most likely caused by the lack of cohesion in linkage proteins. I never looked farther than the surface on this topic and I believe more and more studies should be done to fully explain the cause of these disorders. I also found it potentially controversial when you said in the future it would be interesting to see the engineering of replicates of the cohesion linkage proteins. I believe people could see this as controversial because creating these replicates could cause people to fix their babies chromosomes causing the babies to be different from the way they originally were. All in all, I see this topic as very interesting, as a topic that should be further researched, and also as a potentially controversial topic.

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  2. I think this article is really neat. The connection between elderly women in society and children with disorders is something I would have never thought of. However I believe there have to be over variables besides age and this simply may be a correlation. In addition the experiment with the fruit flies truly demonstrated a unique connection between humans and nature. I really hope to see more research in this topic in the future!

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  3. I'm glad so many of you picked this article to read. Many doctors downplay the role of age so as not to "scare" women who choose to hold off on kids for awhile. Unfortunately, if you hold off for to long, not only does your chance of any pregnancy decrease, but the chances of issues resulting from that pregnancy increase. It is always better to know the whole truth and then make an informed decision. I'm am hoping with these new insights into the "why" of these medical issues, we can soon create a fix for them.

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