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Class of 2017: Peter Ristow Defends Detection of DNA Fragments

Class of 2017: Dr. Peter Gustav Ristow develops forensic methods for DNA detection for low-budget labs

The December 2017 graduation ceremonies at the University of the Western Cape have yielded numerous stories of success - and newly-capped PhD graduate Dr. Peter Gustav Ristow has earned a place on that list with the development of a low-cost and highly customizable method for the detection of DNA fragments.

In a first for the UWC, Peter Ristow publicly - and successfully - defended his PhD dissertation in an international teleconference held in the Faculty of Science boardroom. After a research presentation and questions session, each lasting roughly an hour, his three examiners - from Oxford University, the Max Planck Institute and Copenhagen University - were more than satisfied with the adept demonstration of his knowledge of the fields of population genetics and forensics.

Ristow’s presentation focused on several peer-reviewed articles he has authored and co-authored, with topics ranging from the genetic elements used in forensics genetics and how they are detected, to what their application is in South African population groups. This research is important because of the large amount of genetic variations in Africa, and the lack of genetic data available for the African continent.

His thesis, Comprehensive analyses of the genetic variation between forensic markers in South Africa: Mitogenomes, Autosomal STRs, and Retrotransposon, studied the design and creation of a low-cost and highly customizable method for the detection of DNA fragments. This method will allow local laboratories with small budgets to process a greater number of samples at more affordable prices, without compromising accuracy.

“The amount of data being created by research scientists for the evaluation of forensic kits has grown significantly over the last twenty years or so,” Dr Ristow explains. “However, the methods for analyzing the data have not - and I wanted to do something about that.”

In light of this disparity, Dr Ristow coded a new online toolkit (FORSTAT) which quickly analyzes genetic data and outputs forensically relevant parameters which can then be easily downloaded.

In a similar vein, he also evaluated two genotyping kits - GlobalFiler® and InnoTyper® 21 - in terms of their application in the South African context. He found that these kits could be an asset to the South African Police Services in special cases that require forensic evidence, and that older kits should be used with caution because of the great genetic diversity of the South African population.

Lastly, he investigated the mitochondrial genome - which is strictly inherited through the mother’s genetic line - taking particular interest in the variations contained within haplo-group L0 (pronounced el-zero). This group is believed to represent the oldest lineage in the world, and is commonly found in the Khoi and San groups in Southern Africa.

In 2014, when Peter started the project, there were only 10 known L0 genomes. His research has added 191 genomes to that data.

It was important to him not only to take samples from donors, but also to make the information gleaned from the sequencing and analysis of those samples available to the communities.

“It’s their information - they deserve to know what it is, and what it means.”

To this end, he has informed several hundred participants of their ancestry and is in the process of ensuring that the remaining donors also receive this information.

Defending The Doctorate: A UWC First

Dr. Ristow was humbled to be the first PhD student to defend their dissertation at UWC in front of a panel of internationally acclaimed geneticists - a process that would not have been possible without his supervisors, UWC’s Professor Maria Eugenia D’Amato and Professor Anders Hansen from Copenhagen University.

Despite experiencing the pressure of such a public defense first-hand, he is in favour of this method, stating that it is necessary to ensure that good science and scientists are being produced.

“I was so stressed at the beginning of the defense, but I actually had the best time,” he says. “To be complimented and critiqued by world experts within my research field is quite an honor and a reassurance that I have achieved some excellence.”

His family, supervisors and students were present to lend support.

His  journey would not have been possible without the support of his family since the beginning.

“It’s such a special day for us,” his dad notes. “A public defense is such a rare thing, and we are very proud of our Peter.”

“Peter is exceptional,” says his supervisor, Prof D’Amato. “He has finished a PhD with four papers published, and defended it well, answering some tough questions.”

The appreciation is mutual.

“I would like to thank the University of the Western Cape and the University of Copenhagen for this opportunity, and for making an exceptional contribution to my knowledge,” says Dr. Ristow. “Also, a big thank you to my supervisors. I think they did a tremendous job in building me.”

He hopes to do some building of his own - in addition to his new job producing genetics testing cases, his main focus for now, he’s also supervising upcoming graduates in his field.  

“I’m in a research environment now, and it’s very stimulating,” he shares. “And training new researchers helps spread knowledge while also sharpening my own skills.”

This brand new scientific doctor has high hopes for his research - that it may impact the forensics community globally and locally.

“The matrices that are created will help low-budget labs, and they can produce a lot more good work a lot more quickly. The potential benefit is enormous - especially in Africa where more data is needed.”