Broadcaster: BBC Radio 4
Review by Amy Evans
This episode of the Radio 4 series Inside Science, presented by Adam Rutherford, offers some useful insights into the Y chromosome, and might be helpful when revising. The 6 minute clip tells you all the basic facts that outline sex determination in humans in a short amount of time.
In the segment, Rutherford interviews Henrik Kaessmann from Heidelberg, lead author on two newly published Nature papers on the evolution of the Y chromosome (see Origins and functional evolution of Y chromosomes across mammals and Mammalian Y chromosomes retain widely expressed dosage-sensitive regulators.
The Y chromosome’s primary purpose is to override the default sex setting, which is female, since it carries the SRY gene. According to Kaessmann, the Y chromosome (and also the X chromosome) were originally autosomes (i.e. ordinary chromosome of which we have two copies) and evolved to become sex chromosomes. This limited role explains why the Y chromosome is ‘losing’ genes; because it only needs to retain the genes needed in sex determination and other male specific functions. Despite this, Kaessmann suggests that the Y chromosome has actually been stable for 25 million years and this ‘decaying’ of the Y chromosome is actually the Y chromosome evolving. As well as male-specific genes it has been shown that the Y chromosome also retains some regulatory genes. The exact function of these genes is presently unknown, but they seem to be essential in processes other than development.
After talking about the Y chromosome the rest of the programme (which can be found at this link) also covers information on avalanches, aphids, lichens and the longitude problems.
Genetic modification of aubergine in Bangladesh has dramatically reduced the need to use pesticides
Broadcaster: BBC 1
Review by Prof John Bryant (University of Exeter)
Fierce opposition to the growth of GM crops, especially in the EU (including the UK), goes back to the late 1990s, shortly after the first successful commercialism of crops bred by these techniques. One of the most unfortunate casualties of this opposition is Golden Rice™, bred by GM techniques to provide extra vitamin-A. Its use in SE Asia would save the eyesight of tens of thousands of children and the lives of several thousand each year. However, its uptake into agriculture has been opposed by anti-GM activists at every step such that in 2015, 16 years after this development was announced to the world, the variety is still not available to Asian farmers. Nevertheless, GM-bred crops are now grown in 28 countries (the programme says 27, which was the total in 2013) on a total area of 182 million hectares and, as pointed out in the programme, the countries in which these crops are grown have not suffered environmental disasters nor have there been any detrimental effects on human or animal health.
This brief background leads us to the theme of the programme which asks whether two newer GM-bred crops may be ‘game-changers’ in respect of public attitudes. The first is insect-resistant aubergines which are now being grown in Bangladesh (where the local name for aubergine is brinjal). These plants carry the Bt-toxin gene, already widely used across the world in insect-resistant maize and cotton. Farmers growing Bt-brinjal are enthusiastic about it: the development reduces their costs, reduces crop losses and above all reduces the use of insecticides which, because of poor safety measures, cause harm to farmers’ health. Continue reading
The programme includes an engaging animated history of our understanding of inheritance
Broadcaster: BBC 2
Genre: Magazine show
Review by Amy Evans
In 2012 well-known comedian (and theoretical physics graduate) Dara Ó Briain launched his eponymous Science Club. This first episode of season 1 focuses on reproduction and inheritance, including the importance of bicycles to human development. Although the show’s approach is light-hearted and humorous, there is actually a lot of information given about genetics and key speakers, such as leading geneticist Steve Jones, are involved so that the information given is up to date (at the time of showing). The show is aimed at viewers who have a relatively basic initial knowledge, but elements of it might be good to watch as a re-cap when starting new modules.
A brief history of genetics (2:46, starting at 02:23, see this clip) a nice animation, summarising our understanding of inheritance from Aristotle via van Leeuwenhoek, Bakewell, Mendel and Morgan and ending with elucidation of the double helix by Watson and Crick.
Does sex work? An interview with Professor Steve Jones. Ó Briain and Jones discuss the inefficiencies of sexual reproduction, especially from the female perspective. Jones argues that invention of the bicycle is the most important step in human evolution, because it allowed intermingling of the gene pools with residents of the next village. Now, across the world, we are becoming much less isolated genetically. After a consideration of the history of the bicycle, they return to discussing the importance of genetic diversity. Generally speaking the marital distance, that is the geographical distance between the birthplace of partners relative to the distance between the birthplaces of their respective parents, gets greater generation by generation. Jones explains that genetic health may improve as we are less likely to encounter recessive mutations common within a subpopulation (for example, if you want to avoid having a child with cystic fibrosis breed with someone from Nigeria). Continue reading
What risks do we have of catching the Ebola virus?
Broadcaster: BBC 1
Review by Will Channell
In this half-hour documentary, Medical doctor and researcher Chris Van Tulleken, investigates the epidemiology of the Ebola virus; with particular focus on the 2014 outbreak in West Africa, and the potential for the virus to get into the UK. This is a useful programme offering both public information on an important current affair and for use as an educational tool in the area of viral physiology and epidemiology.
The programme starts by giving background information on the outbreak, before quickly introducing ideas on how the British government are tackling it. Van Tulleken explores the secretive research facilities at Porton Down and the highly secure laboratories in which the Ebola virus is studied (http://bobnational.net/record/292484, 4 minute clip).
Using interviews combined with computer graphics, he guides the viewer through the physiology of the virus, explaining areas relevant to the virus’ pathogenicity. Following this the viewer is guided through the symptoms and treatment of Ebola using further interviews with people who have first-hand experience of the recent epidemic, including British survivor nurse Will Pooley and MSF doctor Javid Abdelmoneim.
Van Tulleken then draws the documentary to a close by detailing transmission of the virus. The emphasis is on reassuring the public of the improbability of infection in the UK. Several factors about the biology of Ebola make it relatively difficult to catch – it is not (currently) contagious by airborne transmission, you need to have contact with the bodily fluids of someone who has the disease.
Any undergraduate microbiologists studying either the Ebola virus or viral epidemiology in general would find this documentary interesting. Despite only being half an hour long the show offers detailed information that would be useful as either a learning or revision tool. In addition to this it walks through the career roles of various research or healthcare scientists.
People interested in this programme might also benefit from the more recent documentary Outbreak: The truth about Ebola.
“Society is going to have to make a judgement on what value it puts on extending the lives of cancer patients against all the other demands on the NHS”
Broadcaster: BBC 1
On 1st June 2015, there was quite a large amount of coverage of a recent clinical trial reported to have had dramatic effects on the survival rates of patients with melanoma (a form of skin cancer). The reason this particular clip (4:45) stands out as useful for teaching is the combination of a clear explanation of what the new cancer immunotherapy drugs are doing, but also the difficult decisions to be made in the light of a growing number of exciting but expensive new drugs for cancer. What price can a health service afford to pay to extend one person’s life when, with a finite budget, buying their medicine means that someone elsewhere in the system will miss out on their treatment instead?
For more on this story see this link (BBC website).