Could bacteria help save amphibians?

Faculty members have teamed up with the Institute of Zoology to investigate the effectiveness of probiotic bacteria in treating Chytrid (Batrachochytrium dendrobatidis) – a fungus that is devastating global frog populations.

Chytrid is a fungus that is thought to be the reason why over 200 different species of frog have gone extinct. This has resulted in 31% of all amphibian species becoming ‘threatened’ according to the International Union for the Conservation of Nature.

A Belize frog, courtesy of Dr R Antwis.

The team, led by former PhD student Dr Rachael Antwis, used bacteria taken from frogs in Belize to investigate the potential benefits of using probiotic bacteria in the treatment of Chytrid. Whilst previous studies have shown that certain bacteria that live on an amphibian’s skin have slowed down the progression of Chytrid, probiotics have not been used in long term field studies.

In assessing the efficacy of probiotics, the team used bacteria on a number of different strains of the disease. Chytrid mutates extremely quickly, so the bacteria must be able to treat different forms of the virus to be effective in the wild. Early results from this investigation suggest that a combination of different bacteria will increase the probability of halting the progression of Chytrid.

The paper resulting from this study, published in Applied and Environmental Microbiology, will act as an important basis for future research into the use of bacteria to help fight Chytrid.

Dr Antwis concludes:

“A lot more work is definitely needed before we can identify an effective cure for this devastating disease. But as a scientist, I believe we not only have a moral obligation to keep searching, but an ecological one too. Amphibians inhabit the middle of food chain, making up a vital part of our ecosystem. If they go, then that could spell disaster for many more species.”

Tuesday Feature episode one: Prof Matthew Cobb.

Welcome to the first Faculty of Life Sciences’ Tuesday Feature. We’ll be here each week with somebody connected to the Faculty,Professor Matthew Cobb be it a researcher, an alumni, a postgrad, or an undergrad, finding out more about their interests, what makes them tick, and how they got to where they are today.

As a Professor of Zoology with a very interesting and unique research subject, who has also written books on hugely differing subjects, we thought Prof Matthew Cobb would be the perfect person to start with.

Hello, Professor Cobb. Thanks for joining us. We’ll start with an easy one – can you please explain your research, for the layman, in ten sentences or less?

I study the sense of smell because I want to know how we’re able to detect different smells. A human being has about 4 million different smell cells divided into about 400 different types, so it’s very difficult to study humans and understand how the process works. So I study the maggot.

A maggot is very simple, it has only 21 smell cells, but the way the maggots brain and nose are wired up are essentially the same as ours. Because these are very special, very tiny maggots that we understand the genetics of, I can make a maggot with just one smell cell. I can record from that cell and see exactly how the maggot responds to different odours and how the whole organism moves when stimulated.

The idea is to try and grasp a very complicated process, which we understand very poorly, using a simple model system.

How could your research benefit the people reading this blog?

Well, I don’t think there’s any applied aspect to what I’m doing. It’s possible that the kind of research I’m engaged in may help us understand anosmia, which is the loss of the sense of smell. If you can’t smell, you can’t taste and people who smoke or have a cold know that stuff just doesn’t taste as nice.

This is a major issue, especially with an increasing aging population. As you get older the smell cells in your nose fail to regenerate and gradually you lose your sense of smell; things don’t taste as nice and your jeau de vivre in general declines. So it’s possible that the research I’m doing, in the end, may contribute to this general problem. But that’s not the focus of my research; it’s more a pious hope.

It’s obviously quite a specific subject, can we ask how you first got interested in this research area?

There are two aspects to what I do. The first is the subject I study; the sense of smell. The second is the organism which I use to study it; the tiny maggot and the fly that produces it. I became interested in studying the genetics of the fly, and the genetics of behaviour using the fly, while reading a very small piece in New Scientist as an undergraduate. It described a study that had just been done in America in which they had made a fly that was stupid; a mutant fly that couldn’t learn. I was a young student studying psychology at the time, very interested in behaviour, and I thought right, that’s what I want to study. And so for the last forty odd years, that’s exactly what I’ve been doing.

I got interested in the sense of smell when studying sexual chemical signals between flies as a way of understanding their mating behaviour. Then we decided, in the late 1980s, to move into olfaction – the sense of smell in general. The person I was working with said I should try and use maggots instead of flies. I told him that was stupid and I didn’t want to do it. That maggots were boring and didn’t do anything. What I was in fact describing was the reason for studying them. They are very, very simple. They only move in two dimensions. They’re not interested in sex. They’re only interested in feeding, which means their sense of smell is a very important drive of their behaviour.

The person I was working with basically told me to experiment and see if it would work. I put my maggots on a little dish of jelly. I put them in the middle. I put the smell on one side and the maggots all moved towards the smell. The difference in that very strong response, compared to the very difficult responses I was getting when studying sexual behaviour in flies, instantly convinced me that this was what I wanted to study.

Do you have science heroes? Who inspired you?

I think I was probably inspired most by one of my lecturers at The University of Sheffield, Professor Kevin Connolly. He was, on the one hand, one of the UK pioneers of the behaviour of this tiny fruit fly, but he was also somebody who was more interested in child development and a lot of other aspects of behaviour. Firstly, he provided me with the opportunity to study this fly – if I’d been virtually anywhere else in the UK I wouldn’t have been able to do that at the time. Secondly, he also inspired me with his lectures. In particular a very intriguing one that I still recall in which he showed that if rats were deprived as pups, which means simply not being held by their parents, they later showed their own strange parenting behaviours. They displayed a non-genetic transference of behaviour and their offspring became deprived as well. That intrigued me at the time and has continued to do so.

Could you tell us a little about your interests outside your research area?

I’ve written two books about the history of science, one about the 17th century and our discovery of eggs and sperm and another about the history of the genetic code which will be published soon. I’ve also written two books about the history of the Second World War, one about the French Resistance in general and one about the liberation of Paris. They’re aspects of history that interest me outside of science.

And that’s it from the first of our Tuesday features. We’re off to learn more about maggots and buy a book about the French Resistance. Many thanks go to Matthew Cobb, and we hope you’ll join us next week when we’ll be chatting to Faculty Alumnus Matt Paul about his research in New York! Thanks for reading. 

Interview by Fran Slater, video by Theo Jolliffe, Image courtesy of Nicholas Ogden

Does it pay to be a lover or a fighter?

As mating season approaches male animals are faced with a question that can determine their chances of reproducing: shouldwalrus (1) they be a lover or a fighter? A recent study, led by Faculty researcher Dr John Fitzpatrick, has found that where animals fall on the lover/fighter scale depends on the extent to which they are able to ensure continued mating rights with females.

In species where fighting for the right to mate means greater control of the female, males invest more in weapons and less in testes size. But males produce large weapons and testes in species where fighting for females occurs both before mating – with weapons – and after mating – with sperm. Some males found fighting the most successful method. Others found fighting was only the first step in sexual relations and also had to rely on large testes to ensure their fertility.

The study looked at over 300 species and found that male ability to monopolise females for continued mating drove the way they evolved. Looking at mammals, birds, fish, insects, and flatworms, they discovered that males only traded-off investment in weapons and testes when they were sure that females wouldn’t fool around with another male when their back was turned. Dr Fitzpatrick said:

“We set out to see why some species show trade-offs in sexual traits and others do not – the answer lies in how successfully males are able to keep females from mating with rivals. We know animals try to get females in a couple of ways. When they fight for them they sometimes evolve weaponry – such as antlers, big body size, or big teeth. The other way they do this is not to bother to compete before they mate, but to have big testes and the highest sperm quality so that they can fertilise the most eggs.”

Dr Stefan Lüpold, from Syracuse University, said:

“You don’t get something for nothing in evolution. We wanted to see which species invested in weapons over testes. Some of these species invest in both, and that is a bit of a mystery. We will now look at whether maximising investment in sexual traits means you pay the price in some other aspect of life. Understanding the way animals reproduce is important as it helps us understand how species evolve and can prove important for conservation.”

Raising awareness of animal research

animalresearch (1)Pupils from schools and colleges across Greater Manchester recently attended a special open day at the University, learning how and why animal research is used in certain situations. They heard how researchers were looking for cures for cancer, epilepsy, Parkinson’s, and age-related deterioration and attended a tour which showed how the animals are kept. The event came following the University’s commitment to developing principles of openness in animal research. Faculty researcher Professor Matthew Cobb said:

“The visit allowed students to experience the conditions and high standards of care we give to our animals. They saw mice, some of which are genetically modified by deletion or insertion of genes, or genes that can be switched on and off. They learnt about epilepsy research in flies and compared young flies and their grandparents to learn about ageing and how it can be studied. Believe it or not, we have lots in common with fruit flies. Many of our organs and structures have the same origins and serve the same purposes. Applying this knowledge from Drosophila flies to humans and human disease is a powerful and effective strategy.”

Mark McElwee, Deputy Head at Parrswood High School, said:

“The event was really worthwhile. The pupils gained an insight into the realities of animal research. It definitely opened their eyes to the potential of animal research for medical benefits and in fact it changed some of their opinions. They were also amazed at the care and dedication put into ensuring the wellbeing of the animals. The feedback from the pupils is that some were so inspired they are seriously considering changing their UCAS applications to go into biological sciences.”

Karolina Zaezyczny, aged 17, from Holy Cross College, said:

“The open day did change my view. It’s made me aware of the positive things and why scientists sometimes have to use animals in their research. I was very impressed with the facilities the animals were kept in.”