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What Can Worms Tell Us About Ageing in Humans?

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What Can Worms Tell Us About Ageing in Humans? “The image shows C. elegans growing on an agar plate. The biggest worm in the picture is an adult and is about 1mm long. We have to use microscopes to look at them because xthey are so small. The worms are also transparent, so if you look carefully you can see their eggs inside and the different cells joining together.” Dr Jennifer Tullet WHAT CAN WORMS TELL US ABOUT AGEING IN HUMANS? A NEMATODE WORM CALLED C. ELEGANS HAS A LIFESPAN OF ABOUT THREE WEEKS, SO WHAT CAN IT TELL US ABOUT HOW AND WHY WE , BASED AT THE AGE? BIOGERONTOLOGIST DR JENNIFER TULLET UNIVERSITY OF KENT, IS INVESTIGATING LIFESPAN AND THE AGEING PROCESS USING THESE WORMS. THEIR SIMILARITY TO MAMMALS MEANS THAT THESE STUDIES CAN ALSO BE APPLIED TO HUMANS The concept of ageing has preoccupied minds The results of these studies can be applied IMAGINE THIS for centuries. For example, Qin Shi Huang, to a range of species, including humans, as the first emperor of China (221-206 BC), is Jenny explains: “We share about 70% of our According to the World Health claimed to have consumed cinnabar – a deadly DNA with C. elegans. Many of their genes, Organization, the proportion of the mercury sulphide – in his quest for immortality. cell signalling pathways and the biology that world’s population over 60 years will While the cause of his death might be obvious, they control are the same. This means that we double from about 11% to 22%. Thanks the question as to why we cannot live forever can use C. elegans to explore topics such as to advances in the treatment of age- remains. And if we cannot live forever, why not neuroscience, behaviour, development and my associated illnesses, e.g. cancer and heart at least for a couple of hundred years? Why do own field, ageing biology.” disease, in recent decades, humans are our pet dogs age so much faster than us and living longer. But not everyone ages well: certain pet tortoises so much slower? Why Scientists have developed clever ways of some people remain healthy right up into can some people stay healthy well into old age, altering the worms’ genome, allowing them their 90s; others are beset with illness whilst others suffer from dementia or cancer? to examine the effects of certain genes on from the age of 60. So, why do some particular functions. “You can also measure people age better than others? This is a Dr Jennifer Tullet is a senior lecturer in several physiological characteristics of ageing in question that puzzles scientists, and is biogerontology within the University of Kent’s worms that can be applied to humans, such as difficult to answer because it is not easy School of Biosciences. Biogerontology is the muscle strength, neurodegeneration, changes to study the ageing process in humans. study of the biological process of ageing and to metabolism and reproduction,” says Jenny. This is partly because we live so long, and Jenny hopes that her research will answer some our lifestyles and genetic make-up are so key questions about how and why we age. WHAT EXACTLY IS JENNY’S LAB varied, making it tricky to assign cause INVESTIGATING? and effect. HOW IS JENNY STUDYING AGEING IF “We don’t just want to find out what makes IT IS DIFFICULT TO STUDY THE AGEING people live for a long time,” says Jenny. “What Imagine if a worm – a nematode worm – PROCESS IN HUMANS? we are really investigating is what makes people could give us the answers scientists need. Researchers in Jenny’s lab are investigating stay healthy for longer.” the ageing process using a millimetre-long nematode worm called Caenorhabditis elegans, Organisms are made up of different types of or C. elegans for short. “This worm is naturally cell, and each cell type has a unique function, found in compost and garden soils,” says Jenny. as Jenny goes on to explain: “To carry out its In the lab, however, it is a ‘model organism’, role, a cell needs not only the genetic blueprint a term given to non-human species that are provided by DNA, but also a whole range of studied by scientists to find answers about tools that tell it which genes to switch on and biological processes. off at any given time”. It is these tools – the 76 Find this article online and download the activity sheet: www.futurumcareers.com DR JENNIFER TULLET Senior Lecturer in Biogerontology School of Biosciences University of Kent, UK FIELD OF RESEARCH Biogerontology RESEARCH PROJECT Scientists in Jenny’s lab are investigating the molecular mechanisms underlying the ageing process, using the model organism C. elegans. molecular mechanisms – that Jenny and her the fluorescent protein is too. The cell where team are researching. this takes place will literally ‘light up’ under the FUNDERS microscope.” The scientists use these visual clues Biotechnology and Biological Sciences HOW DO THE RESEARCHERS USE to identify where in the worm’s body the gene is Research Council (BBSRC), WORMS AS A RESEARCH TOOL? expressed, and at what stage it is in its lifetime. The Royal Society “Because C. elegans only live for about three weeks in the lab, we can easily follow and measure WHAT HAS JENNY’S TEAM DISCOVERED their entire lifespan,” says Jenny. “For lifespan SO FAR? similarities in how humans and worms function. experiments, we take ~100 worms at the start of “Science is hardly ever about eureka moments. By uncovering the processes that control their adult lives, place them on agar plates with It is normally small discoveries that build upon ageing and age-related disease in these worms, plenty of food and monitor them over the course how we view biology as a whole,” says Jenny. biogerontologists like Jenny can increase our of their lives.” “My team and I have made plenty of these little understanding of ageing and age-related disease discoveries, but perhaps the most significant in in people. Using C. elegans, scientists in Jenny’s lab can recent years is the identification of a new protein perform a wide range of specific experiments. involved in controlling lifespan called RNA And if you are interested in helping people For instance, they can measure how a worm’s polymerase III.” Jenny’s team collaborated with live healthier lives in their old age, then movement changes as it ages, or track its fat labs in London and the Netherlands to study biogerontology could be the career path for you. content or the number of offspring it produces this protein in worms, yeast and flies. The next As Jenny says, “Understanding more about how – the same characteristics that change as stage is to see whether these results from model the ageing process happens means that we might humans age. “We have also been doing some organisms apply to humans. be able to alleviate some of the discomfort and very interesting behaviour experiments,” says illness associated with it.” Jenny. “We are testing the roles of certain genes Jenny is also investigating another protein called in sensing food, eating and determining a worm’s SKN-1, which has led to some surprising results. hunger and satiety (feeling full).” “Earlier in my career I studied the role of SKN-1 as an important longevity gene, but our current To pinpoint which genes lead to changes in research suggests it also has an exciting role in movement, fat content or behaviour, for example, food-related behaviour. There is never a dull the researchers remove or alter the function of moment!” she says. certain genes from the worm’s genome to find Fluorescent labelling of cells in the worm. out what they do. “We can also insert the gene WHAT DO THESE WORMS REALLY HAVE Proteins are expressed that are joined to a GFP tag so that when they are switched on the GFP for fluorescent proteins into a worm’s DNA next TO DO WITH US, THOUGH? lights up and you can see where they are. to any existing genes that we are interested in,” Even though worms are completely different says Jenny. “If the gene of interest is expressed, to humans, there are still a great number of 77 ABOUT BIOGERONTOLOGY Biogerontology is the study of the biology are a good step into biogerontology, but research,” says Jenny. “It offers great behind the ageing processes. It is distinct notes that biologists and geneticists are not opportunities for lifelong learning, alongside from gerontology (which studies the impacts the only ones studying ageing: physicists, a good amount of flexibility and travel. My of ageing on individuals and society, rather physicians, engineers, computer scientists, favourite aspect of the job is all the great than the root biological causes of ageing), and mathematicians are also known to be working people I have met along the way. The people from geriatrics, which specialises in healthcare in this area. Ultimately, as Jenny says, “Any are the reason I keep at this career, even in measures for the elderly. Naturally, there career in scientific research requires the tough times.” is overlap between the three specialisms. ability to always be learning and developing For instance, understanding the biological transferable skills. I am learning new things processes behind ageing can help inform the all the time. Like any field of science, it is treatment of age-associated diseases. impossible to know everything, and new developments can happen very fast!” WHAT SKILLS ARE NEEDED FOR A CAREER IN BIOGERONTOLOGY? IS A CAREER IN BIOGERONTOLOGY According to senescence.info, a website RECOMMENDED? about ageing research, biology and genetics “I would recommend any career in scientific OPPORTUNITIES IN BIOGERONTOLOGY • Several UK university courses offer optional modules related to ageing.
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