09 May 2011
ByAppeared in BioNews 606
BBC4, Monday 18 April 2011/Monday 25 April 2011
Presented by Dr Adam Rutherford
Nearly twenty years ago, a medical school I know well was deciding whether to incorporate the university genetics department. One senior medical professor cautioned that science-focused geneticists would be well advised to stop studying fruit flies, snails and other animal species in favour of 'real genetic research' into human genetics.
I wonder if that professor was watching the first of two excellent programmes about 'The Gene Code', written and presented by Dr Adam Rutherford? The first episode was subtitled 'The Book of Life' and began by describing DNA metaphorically as an epic poem of life on earth.
What a high standard this first programme set. I see from BBC blogs that others were equally impressed with Dr Rutherford's clear decisive presentation. The many experts interviewed also deserve commendation.
During the programme, we visited Iceland's hot springs and were introduced to heat, acid and salt-resistant species called archea. We learned how – when they were penetrated by bacteria – they created intracellular mitochondria, leading the way to multicellular organisms. Among the other facts fitted into the programme were how boa constrictor snakes (with 304 vertebrae) have genes for bone development essentially similar to those of humans.
Dr Rutherford emphasised that similarities between genes of different species indicate their origins from common ancestors - something that the senior medical professor hadn't grasped in 1993. Moreover if genes are similar between species, it implies their functions are of greater evolutionary importance than inactive genes present in primitive species.
The second episode covered single gene diseases, showing how a gene's discovery led to increased options for families previously too concerned about risks in future offspring to take the risk of pregnancy.
The introduction was especially striking. We met Dr Hugh Reinhoff, a clinical geneticist whose daughter, Bea Bea, had several congenital and developmental abnormalities. Dr Reinhoff arranged sequencing of DNA from Bea Bea searching for coding regions that may be linked to her condition (1). The results are not yet conclusive, but this father's journey on his daughter's behalf may be repeated in other families.
After Dr Reinhoff, we met Professor Kay Davies. She described her great relief when the first Duchenne muscular dystrophy (DMD) prenatal diagnosis showed neither fetus of a twin pregnancy had inherited the DMD gene mutation.
War-toughened CBS reporter Charles Sabine then described the human side of discovering he was at high risk of Huntington's disease (HD). Although he'd been in Bosnia and Afghanistan during conflicts, he said nothing was as terrifying as discovering that he had inherited the gene for HD (2).
The episode then tackled the complex area of common, multifactorial genetic disorders. We were given a simplified explanation of the chain termination method of DNA sequencing, which earned Professor Fred Sanger his second Nobel prize! Then we learnt how our entire DNA is identical except for about one in 1000 base pairs.
These facts lay the ground for Professor Peter Donnelly to take us into genome wide studies for associations with complex diseases, and Mark Hirst to illustrate the methods in type-2 diabetes. Dr Claire Haworth described and demonstrated her work with both identical and non-identical twins, exploring the variance in heights and in personality traits between the two groups.
I feel quite breathless as I list just some of the amazing material used by Adam Rutherford in his wonderful programmes. Among these, an explanation of how we've revised our best estimate of the total number of human genes from between 50,000 and 100,000 in 1994 to only 24,000 genes today.
After two wonderful programmes for which Dr Rutherford and his team deserve the heartiest congratulations, I have only one major grouse. Such important material should be available for replaying again and again, not restricted to about a week on the BBC iPlayer.