Who's Your Momma?...Mitochondria

Background:
     Since the first signs of life, single-cell organisms have contained DNA that gave the origin of their existence. Mitochondria is an example of one of those organisms. It is believed that the mitochondria used to be free-living cells that were captured by eukaryotic cells. This created a symbiotic relationship for the eukaryotes and mitochondria, one gaining nutrients and the other gaining a mechanism to use oxygen for energy. Mitochondria have a unique set of DNA (37 genes) that result from single nucleotide polymorphisms (SNP), which can be used to trace ancestry. In fact, they did. At UC Berkeley, they discovered by tracing generations to a common ancestor, modern humans came from Africa, 200,000 years ago. They realized that the mtDNA is only transferred by the mother to the egg cell. This mtDNA is very important to analyze because it can identify unknown human remains, trace generations, and relate different species to one another. Some disorders may  occur when some mitochondria in an organism's cells do not match up with other cells in the body, called heteroplasmy. These disorders occur in adulthood, as opposed to homoplasmy, which stops embryonic development in the first place.

Purpose:
The purpose of this lab is to understand and better understand mitochondrial DNA and its purpose.

Procedure:
For this lab, we extract our DNA the same way we did for the Disease Gene lab, involving saline solution, instagene matrix, and PCR. The new material to this lab is the mitochondrial DNA. We will use primers to bracket the mt  control region, which will only copy the the specific section of DNA. Afterwards, we will do the same gel electrophoresis that was done in the previous lab to tell us how similar our mitochondrial DNA is.

Results:
Based on our gel results, we saw that the mitochondrial DNA had almost identical bandwidth. This is not a surprise because 99.9% of human DNA is identical. We will send the rest of our DNA samples to the lab for sequencing so that we can compare our DNA even further.

Discussion:
Mitochondrial DNA is important for tracing our origins and studying evolutionary patterns. Doing this lab allows us to understand our development and have us realize how we are connected to others. Because DNA is universal, it is easy to map out our DNA history and at the same time, see ways that we could possibly develop. Minute details in our DNA have been found to cause significant problems, but if we could learn the different aspects as a whole and eventually head off future problems.

The Disease Lurking In Your Genes

Background:
The concept of DNA testing has been around since the discovery of DNA's composition, but has only been exercised recently in the 21st century. DNA testing in its simplest form is comparing sets of DNA in order to identify their differences and analyze how they are expressed in organisms. DNA testing is relevant to every day life because it is used in paternity testing, forensics, species comparison, migration studies, and, in our case, genetic disease testing. The process of DNA testing involves extraction of DNA, through bodily secretions, skin cells, blood, fingerprints, or hair etc. After DNA is broken out of its cell, the DNA is copied multiple times through processes like PCR (polymerase chain reaction). Gel electrophoresis is the most common process for DNA to be compared through. If the DNA is positive for whatever is being tested, it will align correctly with the bands of the positive control. For this lab, we will use these examples in our procedure.
Purpose:
The purpose of this lab is to fully understand the process of DNA testing. Whether our fields of study will include genetic testing, or if we choose to be tested for genetic diseases in the future, it is important to be aware and knowledgeable.
Procedure:
Day 1: After rinsing our mouths with saline solution to remove foreign particles, possibly containing DNA, we swab the inside of our cheeks to take our epithelial cells that contain DNA. We gain access to the DNA inside by breaking the cell and nuclear membranes with a hot water bath at 95 degrees centigrade. Doing so, leaves the DNA exposed to DNAse which will destroy it, unless we add the Instagene Matrix Beads, which will kill the DNAse.
Day 2: Our next step is PCR, so that we can make multiple copies for research. This involves the following - DNA template (original DNA), deoxynucleotides (raw material), DNA polymerase (enzyme to put them together), Magnesium Ions (catalyst to create the chain), oligonucleotide primers (specify the specific place to begin replicating), and a salt buffer (creates the perfect environment for PCR).
Day 3: The last step is gel electrophoresis. To review, we take the replicated DNA sequences and loading dye and pipette the mixture into the agarose gel. Add the control results for comparison. Now targeting this specific gene, not an actual disease gene because that would have ethical dilemmas, can yield 3 results. Either the sample can be homozygous dominant or homozygous recessive (long strand/long strand or short/short), meaning they are the same, or the third option, heterozygous (long/short).
Results: With the overall class, there were three times as many diseased individuals who tested homozygous recessive. At our lab table, Lizzie was the only one who had definitive results (heterozygous), because the other three of us must have punctured holes through the bottom of the gel, causing it to leak and not give us definitive bands. If we were to get results, we would simply compare the bands of the controls and see with which set our DNA would match.
Discussion: As previously stated, our largest source of error was the gel puncturing. This was extremely disheartening because we are left hanging with the results, because we no longer have our DNA samples. If we had failed somewhere else, we could have done one of the following: insufficient amount of DNA from the cheek cells, using the centrifuge instead of the vortex, or gathering matrix that would have killed the DNA in the PCR machine. After having these results, this will drive us to be more careful next time.