Vast non-coding regions of the genome have been dismissed as junk for years. However, by using qPCR (quantitative polymerase chain reaction), biologists at Texas A&M have found that some of these stretches of code, known as heterochromatin, are far from rubbish and could actually cast light into complex diseases such as cancer and diabetes.
Heterochromatin makes up a large part of the human genome. It is largely non-coding, and is formed from tightly coiled and closely packed repetitive strands of DNA, with associated proteins. While it seems that heterochromatin has a role in maintaining the structure and function of the chromosome, little has been done to sequence it.
The researchers modified a real-time quantitative PCR-based method and added in a fluorescent dye to quantify simple repetitive satellite sequences and look at the dynamics of the heterochromatic sequences in the Y chromosome of Drosophila melanogaster. The results, which were published in PLoS One, showed that mutations in the heterochromatin could affect other parts of the genome.
“There is so much talk about understanding the connection between genetics and disease and finding personalized therapies,” says Keith A Maggert, an associate professor in the Department of Biology. “However, this topic is incomplete unless biologists can look at the entire genome. We still can’t — yet — but at least now, we’re a step closer.”
This modified qPCR-fluorescence technique, developed by doctoral student John C Aldrich, is cost-effective and time-efficient according to the researchers.
“There’s some sequencing technology that can also be used to do this, but it costs tens of thousands of dollars,” says Aldrich. “This enables us to answer a very specific question right here in the lab.”