Professor Brown and his team then searched for the gene sequences for tuberculosis. Because it is a bacterial disease the bacteria's DNA can remain in the bones after death.
Talking about the process Professor Brown said: "Previously we could only scan the bone sample for specific genes. We wouldn't see everything that was there which meant we could easily miss other genetic information that could be relevant. Using the hybridization screening meant we could search for different strains of TB, not just one."
About 280 bits of sequence in the DNA were found to match known tuberculosis genes. The data placed the historic strain of TB in a group that is uncommon today, but was known to have been present in North America in the 19th century. In fact it was found to be very similar to a strain recorded in a tuberculosis patient in New York in 1905.
Discussing the results Professor Brown says: "The fact that this particular strain of TB was found in both North America and in the skeleton from 19th century Yorkshire is not necessarily unusual. There were many migrants from Britain to America during the 19th century so it makes sense that TB strains were spread."
One of the downsides of hybridization capture identified by the researchers in this study was that it is possible to mistakenly identify DNA. Because it looks at all the sequences across the sample it may identify DNA that isn't from the bone, but actually from the surrounding soil or environment where the skeleton was buried.
In this study the results were checked using the more traditional method of polymerase chain reactions and were found to be accurate. The researchers concluded that using hybridization capture and next generation gene sequencing is an accurate and effective way to obtain detailed genotypes of ancient varieties of tuberculosis. It could potentially be used to study other disease
|Contact: Morwenna Grills|
University of Manchester