My Second Genome
Sydney Hickam
Biology 1010
Mon, Wed,Fri
In the past every person had one set of DNA that could be used to identify them and to use in need of organ transplants. As time has pasted and technology has gotten better we have been able to identify people who have more than one set of DNA. A woman in 1953 donated a pint of blood that contained both type A and type O blood; science can conclude that the women got the second strand of
DNA from her twin brother while they were still in the womb.
In 2012 a Canadian scientists did autopsy’s on the brains of 59 women. What the scientists found were 63 percent of them had Y chromosomes on their neurons. They believe that the chromosomes are from the male fetuses that they gave birth to. This type of women with a second DNA strand from their child is called a chimera. What was thought to be a rarity in society is in reality a normal thing. Dr. Linda Randolph of the Children’s Hospital in Las Angeles said “It’s pretty likely that any woman who has been pregnant is a chimera.”(Zimmer) At the age of 52 a woman in need of a kidney transplant was tested to find a match, later when the test came back the results denoted that she was not the mother of two out of her three biological children. With more testing done it came to be that she originated from two genomes, one genome sired her blood and part of her eggs and the other genome sires other eggs.
Finding out that one person can have multiply DNA sequences may cause some problems for genetic councilor’s who look for DNA mutations. Having to DNA sequence multiple times for a simple person to look for anomalies and mutations will take more time and more patience that what was already needed. For forensics this may also come as a problem, bone marrow transplants have perplexed forensic teams, by causing the new marrow to introduce a new genome into a body.
Researchers at Innsbruck Medical University in Austria took cheek samples from 77 people who had

Sydney Hickam
Biology 1010
Mon, Wed,Fri bone marrow transplants within the last nine years and checked for multiple genomes to be present. 74 percent of the participants were found to have a mix of genomes, both from the bone marrow donor and from their original genome. The genomes and not just altered the blood cells but also the cells of the cheek. But Manfred Kayser, a professor of Forensic Molecular Biology at Erasmus University said
“This should not be much of a concern for forensics.”(Zimmer) Having done more tests in the Austrian study it was found that no bone marrow genome was found in the hair of the recipients.
With the new understanding of chimerism another genetic mutation has come to light: mosaicism. A mutation caused when the cell divided and is a new to that animal. Before DNA sequencing was available it was hard to study this is humans, unless it had major effects. A form of leukemia was found to be a result of mosaicim in 1960, which caused later scientists to come to the idea that cancer is result of mutations on specific cells.
With all of the new information becoming available to scientists it brings up more questions that scientists need to figure out. New information about how diseases and how cancer may have started gives way to planning on how to stop or prevent such cancers. Will this help us find a cure for cancer and other genetic mutations? How will this add to the diseases that are already present on our society?
The new advances in DNA sequencing and the differences in what makes us human is a topic that is fascinating to hear about and to read. This is the information of what makes us who we are, how we act and what makes us different from all the other species of mammals on the planet. Genetics is how we find our origins and how we will discover what there is to come. With science there will always be a question to be answered after the last question. Biology and genetics will have doors for us to open until we have the technology to figure out the answers to the universe.

Zimmer, Carl. "DNA Double Take." New York Times 16 09 2013, n. pag. Web. 30 Sep. 2013.
Sydney Hickam
Biology 1010
Mon, Wed,Fri
<http://www.nytimes.com/2013/09/17/science/dna-double-take.html?pagewanted=all&_r=0>.