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New Zealand fish and chips hold human DNA clues

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Before you pop that piece of battered fish in your mouth, be aware it might just hold the key to understanding the origins of a form of DNA memory critical to human development.

The unusual looking elephant shark (Callorhinchus milii), commonly used in fish and chip shops throughout New Zealand, is only a very distant relative of humans.

But University of Otago geneticists have discovered it has a remarkably similar DNA memory system to our own.

"This memory is made up of tiny chemical tags called methylation, which are used to tell a cell what its job is and make sure it stays dedicated to it," research leader Dr Tim Hore, of the Department of Anatomy, says.

The DNA memory system that belongs to humans has only been found in vertebrates – animals with a backbone such as mammals, amphibians and fish – and researchers have long wondered how it evolved and how far back in evolutionary time it exists.

First author of the study, Dr Julian Peat of the Anatomy Department, says the fact elephant sharks also use methylation-tagging to turn off genes tells us this memory system has been around a long time.

Our ancestors split off from elephant sharks more than 460 million years ago.

“Our study identifies elephant shark as the most evolutionarily distant animal that shares this DNA-regulation system with us humans, which makes it very...

The full text of this article can be purchased from Informit.