Yeast as a model organism

For the past eighteen months Professor Andrew Fry and I have been working with the video production team at the University of Leicester to create a series of resources about the use of model organisms in medical research. The work has been funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and GENIE, the Centre for Excellence in Teaching and Learning in Genetics Education.

The centrepiece of the project will be a video of about twenty minutes duration, but we are also releasing some of the material in shorter formats. Squeezed in around other tasks, filming and editing has been a slow old process (note to interested parties: never enter lightly into film production!). The first fruits of this process are, however, starting to emerge and we have recently uploaded three videos to YouTube. All three relate to the work of Professor Rhona Borts from the Department of Genetics at the University of Leicester

The first video is the most concise edit and will correspond closely to the relevant section of the final film. In this clip Rhona summarises the features of yeast that make it ideal to use as a model organism.

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Obituary: the death of a dear friend?

The HE Academy have announced the phasing out of the Subject Centres

We are all aware that the UK is in a financial mess and savings need to be made. The nearer the guillotine falls to your areas of interest the more intensely you are going to feel the pain. The tragedy comes when cuts kill off services of genuine merit and value. The recent announcement that a spending review by the Higher Education Academy will result in the closure of the Subject Centre network is a huge body-blow.

Although the closure had been anticipated, the loss of the UK Centre for Bioscience is likely to have a significant negative impact on the student experience. It was been my privilege to become involved in the work of the Centre from its earliest days, and I want to put on public record some of the benefits that have I have drawn from their work. Continue reading

Casting new light on the origins of Plasmodium falciparum

Anopheles mosquitos spread malaria

Malaria is a disease that has killed more humans than any other during our history; it still infects some 500 million people each year, killing about 2 million. Although a bite from a female Anopheles mosquito is central to the transmission of malaria, it is in fact a Plasmodium pathogen harboured within the mosquito that causes the disease. There are five distinct species of Plasmodium known to cause malaria – of these P. falciparum is the most significant both in terms of quantity and severity of infection.

Having entered the body via a bite, the pathogen migrates in the bloodstream to the liver. From here it will re-enter the blood stream and colonise red blood cells. When sufficient multiplication of the pathogen has occurred, the blood cells will burst, releasing more pathogens into the blood. The bursting occurs on a 48-72 hour cycle and is accompanied by peaks in fever and other symptoms at these times.

Persistent and repeated damage to the red blood cells leads to a shortage of erthyocytes and associated symptoms of anaemia. Rarely, P. falciparum can cause blockage of blood vessels supplying the brain, resulting in insufficient supply of oxygen, leading to brain damage, seizure and/or coma (all data taken from the NHS Choices website).

New evidence undermines traditional view on the origins of P. falciparum

In a September 2010 paper in the journal Nature, Beatrice Hahn and colleagues investigated the evolutionary origin of P. falciparum (Liu et al; doi:10.1038/nature09442). Prior to publication of this research, it was believed that P. falciparum infecting humans had evolved from P. reichenowi in chimpanzees. Until recently this had also been considered as a classic case of “host-parasite co-divergence”, i.e. that when the human line had diverged from the chimpanzee line – between five and seven million years ago – they were both already infected with the same ancestral Plasmodium species which had subsequently evolved apart at the same time that the hosts had evolved. However, three studies already published in the previous 18 months had questioned this chronology (whilst still believing that chimpanzees were the reservoir from which the ancestral version of P. falciparum had passed to humans). Continue reading