Hello and thank you for downloading our history program witness with me Louise Adago.

As part of the BBC's a hundred women series, we've been speaking to some of the women who've been overlooked by contemporary history.

I've been hearing from scientist Elizabeth Fisher who with

her colleague Victor Tablievich successfully transplanted human chromosomes into mice for the first

time. It was a success that would transform medical research

into the genetic causes of disease,

and in particular the genetic condition Down syndrome.

It's 1991 and in a pub in West London two friends, both of them scientists are talking over a pint about life and science. And we started thinking or I started thinking about Down syndrome,

which is a very, very common disorder,

probably about one in 800 births around the world, people with Down syndrome,

and that arises because they have an extra chromosome.

And we started to think, well, we really know very, very little about this disorder.

We don't understand why it arises.

Sure it's because people have an extra chromosome,

but how do we investigate further? How do we really get to grips with it?

Very difficult to do with human studies.

So given both of our background studying mice

we just started to talk over several pints of beer weekly about you know could we make a mouse

model of Down syndrome could we do something that would contribute to our understanding of this

disorder. Elizabeth Fisher's background was mouse genetics investigating the

similarities between mice and human genes. Her friend Victor to Bulitch's was genetic engineering.

What together they were about to embark on, transplanting an almost entire human chromosome

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