Mice or Men? How Important Is Conserved DNA? A Conversation with Geneticist Nadav Ahituv

Illustration of two mice and two men

Nadav Ahituv, PhD, likes to juggle. This assistant professor in the UCSF School of Pharmacy’s Department of Biopharmaceutical Sciences – and member of UCSF’s Institute for Human Genetics – even spent time training with a circus. It’s a handy skill when you’re trying to understand genetic controls, particularly those that are somehow embedded in the non-coding regions of our DNA – regions that make up more than 90 percent of our genome.

Photo of Nadav Ahituv

Nadav Ahituv

In viewing this vast panorama of nucleic acids – and all their possible interactions and relationships – Ahituv looks for patterns. And when you’re looking at DNA, one of the more interesting patterns absolutely has to be those sequences that are 100 percent identical in different species.

Take mice, rats and humans, for example. Yes, we share a common ancestor. Somewhere around 80 to 85 million years ago, we took a different evolutionary path. But some parts of our genome – to be precise, 481 DNA sequences – remained the same. Not kind of the same, but exactly the same.

While it’s tempting to use this piece of rodent evidence to explain why some people behave as they do, the real news is that shared sequences by their very persistence over millions of years must be important and maybe even indispensable.

Or so scientists hypothesized. But that’s one of the many great things about scientists. They test their hypotheses. And that is why Ahituv and his former colleagues at Lawrence Berkeley Lab’s Genomics Division knocked out four different non-coding regions in mice to see what would happen.

One would expect that the mice would have either died or been unable to reproduce. After all, it was widely believed that these non-coding regions near critically important genes act to enhance and regulate the various messages genes are capable of producing.

But eliminating them did not seem to have any effect at all. It was a huge surprise. Just how big – and what it all means – is something Ahituv is now trying to understand.

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Related Links

UCSF Institute for Human Genetics
Department of Biopharmaceutical Sciences
UCSF School of Pharmacy
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