As promised, this week’s blog is about some of the current research regarding chromosome 21 that I discovered during the course of my Independent Research and Design (IRaD) project. I found this part of my project particularly interesting because the research is conducted on mice. The concept that scientists can find convincing and factual information from a species that seem so different than humans was strange to me. Mice, however, are nearly identical to humans in their gene content, order, and spacing in every region. Therefore, mice actually make the perfect specimen for genetic testing—in addition to being cheap and easy to find.
There is some variation in the symptoms of people with Down’s syndrome; however, overall everyone with trisomy 21 have very similar physical features. In order to understand why people with Down’s syndrome have the features and symptoms that they do, the current research uses mice to help understand what the genes on chromosome 21 code for. 1
The experiment uses a knockout method that tests mice for a few sections of chromosome 21 at a time. In order to carry out this test, pieces of chromosome 21 (regions) are knocked out of the chromosome and placed in a mouse to test for changes that relate to Down’s syndrome. A similar test has been done on mice with other chromosomes and it has shown changes in the mice that have helped scientists understand certain trisomies better. 1
While doing this test, scientists must be careful and attentive because, although mice are very similar to humans genetically, mice are also very different. When using the knockout method, they could end up testing for a gene that is completely different in mice than in humans. Not much has been found out about the genes on chromosome 21 because testing started only several years ago and is very challenging. Many of the physical symptoms that are found in humans with Down’s syndrome are in the eyes, hands, and tongues. Mice react very differently to these physical changes and have made it difficult for scientists to decode the genes.1
I hope that advances in science will provide us with more answers about Down’s syndrome and chromosome 21. Thanks to my IRaD Project I have a better scientific understanding of Down’s syndrome and I learned about a topic I am deeply committed to. This section brought me to the end of my study of the genetics of Down’s syndrome. My next blog about my IRaD project will discuss the relationship between dance and Down’s syndrome; stay tuned!
Dance, move, and empower,