Driving Down Pests – The Scientist, August 28 2017

 A computer model estimates that gene-drive technology could wipe out populations of an invasive mammal on islands. 

The government of New Zealand has a goal: to wipe out the most damaging introduced predators in the nation by the year 2050 through the Predator Free 2050 program. At present, rats, possums, and stoats have pushed native species such as the kakapo to near extinction and cost the country NZ$70 million (USD$50.5 million) in pest control measures and NZ$3 million (USD$2.2 million) in agricultural losses annually.
Acknowledging that the existing pest-control methods are not going to be enough for this ambitious project, scientists involved in the program have placed their hopes in engineered gene drives: a technology that involves meddling with the rules of inheritance and increasing the likelihood a deleterious gene will be passed to the next generation of a species. With the advent of the gene-editing tool CRISPR-Cas9, which allows scientists to alter DNA at precise locations using a single guide RNA and a DNA-cutting molecule called Cas9, the idea of using gene-drive technology to turn populations on themselves is now within reach.

In a study published August 9 in the Proceedings of the Royal Society B, researchers at the University of Adelaide have provided modeling evidence that gene drives could indeed be an effective means to wipe out entire populations of invasive vertebrates on islands.

“The most obvious potential advantage to using gene-drive technology for this purpose is species specificity,” says Luke Alphey, a genetic pest management expert at the Pirbright Institute in the U.K. and a cofounder of Oxitec, which is commercializing other genetic-modification methods to control insects. “Genetic approaches are transmitted through mating, so the direct effect is only on the target species.”

“That aspect alone is phenomenally powerful if we are talking about working in an ecologically fragile environment,” notes Alphey, who was not involved in the study. He says the current approach for managing invasive species consists predominantly of “harmful mass poisoning.”

In this recent study, the scientists chose to test gene-drive strategies on a simulated island population of 50,000 mice that they constructed in silico. Invasive rodents are likely responsible for the greatest number of extinctions and ecosystem changes on islands, according to a 2006 study. The house mouse (Mus musculus) in particular has been shown to have a devastating effect on seabird colonies in places such as Gough Island in the South Atlantic and New Zealand’s Antipodes Islands.

“We also focused on islands because in the long term . . . if this technology is deemed a good idea and acceptable by society, islands will be the first place it is carried out as it is easier to control,” explains coauthor Paul Thomas. “There’s a long way to go before we think about using it, but we wanted to conduct this study to see if it could be a possibility.”

Using a mathematical model, the scientists tested four CRISPR-based gene-drive strategies that could be readily developed based on what is within the current literature. The “heterozygotic XX sterility” strategy, also known as the “daughterless strategy,” involves using the gene drive to spread a male sex-determining gene so that all carriers develop as males regardless of their sex chromosomes. As a result, there will be a deficiency of females and the population will eventually crash.

“Heterozygotic XX sex reversal” is a similar technique, but contains additional genetic cargo that enables XX males to transmit the gene drive. “Homozygotic XX sterility” achieves population suppression through the infertility of homozygous females. The final strategy, “homozygotic embryonic non-viability,” causes embryonic fatality through gene mutation. All of these strategies were based on the basic CRISPR-Cas9 system using a single guide RNA.

The heterozygotic XX sterility strategy failed to present itself as a viable method, the researchers found, as carrier XX males are infertile and therefore unable to pass on the gene drive. The paper notes that this method would only prove effective on the basis of a continuous release of gene drives into a population, a process that would be costly and time-consuming.

The remaining three strategies proved capable of causing rapid population decline to the point of elimination. The researchers conclude that a single introduction of just 100 mice carrying one of these gene drives could destroy an island mouse population of 50,000 individuals within four to five years.

The researchers acknowledge that, for all of these strategies, the potential for the formation of resistant genes poses a problem, as has been observed in laboratory studies of mosquito gene drives. However, by conducting further tests that involved targeting several different DNA sequences with more than one guide RNA, they found that the possibility of this resistance is reduced.

Michael Wade, who studies population genetics and mating at Indiana University, is not convinced that this solution to resistance comes without consequence. He says that by using multiple guide RNAs as the authors suggest, one could increase the risk of targeting the genome at unintended sites, which may lead to other problems.

“Release of this type of construct raises the risk of reducing the target specificity of CRISPR-Cas9 and increasing the possibility of it jumping to a different species, possibly an endemic relative of the invader species targeted for eradication,” he writes in an email to The Scientist.

Concerns have been raised by members of National Academies of Sciences, Engineering, and Medicine in a consensus study report about the potential consequences of using gene drives for species eradication, including the unintentional spread to other populations, unpredictable negative effects on the ecosystem, and ethical implications. Thomas and his colleagues are “very conscious” of these worries, he says.

“I think this method definitely has potential but we do need to do more studies, have the conversation around whether it is safe to use, and see if the benefits outweigh the risks. We are keen to engage with all members of the community,” he says. His team has now begun conducting a mouse-based gene-drive experiment in the laboratory.

 

T.A.A. Prowse et al., “Dodging silver bullets: good CRISPR gene-drive design is critical for eradicating exotic vertebrates,” Proc Royal Soc B, doi:10.1098/rspb.2017.0799, 2017.

 

(First published on The Scientist online on August 28 2017. Available online at: http://www.the-scientist.com/?articles.view/articleNo/50180/title/Driving-Down-Pests/)

Advertisements

What is the best antidote for a jellyfish sting? (Clue: it’s not urine) – The Guardian UK, May 9 2017

What should you do if a jellyfish stings you? Scientists have found that applying vinegar is the best solution, and that popular remedies including urine, lemon juice, and shaving foam could make the situation worse.

A recent study in Toxins, which investigated the efficacy of various remedies for stings from the Portuguese man o’ war (Physalia physalis) concludes that rinsing with vinegar before applying heat is the most effective treatment. The commonly recommended treatment of seawater and ice was found to cause more harm than good.

Dr Tom Doyle, a biologist at NUI Galway and co-author of the paper, conducted research on both the Atlantic and Pacific man o’ war. He said the findings represented a complete U-turn.

“For me it was certainly surprising as we have been recommending seawater and ice for the last 10 years,” he said. “But that’s the nature of science; we have to hold up our hands and say we were wrong. We went back to basics and tested different methods. There’s no doubt about our findings. We are absolutely 100% certain that vinegar does the trick.”

The scientists tested various solutions on sheep and human blood cells suspended in agar. The method of scraping away tentacles was found to increase pressure on the affected area, causing the stinging capsules to fire more venom into the victim. However, applying vinegar was shown to prevent further venom release, allowing the tentacles to be safely removed. Immersing the area in 45C water or applying a heatpack resulted in fewer red blood cells being killed.

In contrast, rinsing with seawater was found to worsen stings by spreading venom capsules further, while cold packs caused them to fire more venom. The infamous urine theory – popularised by an episode of Friends – was also found to aggravate stings. Baking soda, shaving cream, soap, lemon juice, alcohol and cola yielded similar results.

Although vinegar is used for many other jellyfish stings, the man o’ war has long been considered an exception, with many guidelines warning against its use. While it’s true that the man o’ war is different – they are technically a siphonophore and not a jellyfish – the scientists behind this research are now arguing that all stings be treated equally.

Biologist and jellyfish expert Dr Lisa Gershwin agrees that treatment with vinegar works, but expressed concern about the hot water recommendation.

“Hot water does take away the pain but this is a neurological process; it has nothing to do with denaturing the venom,” she said. “Fresh water activates discharge and by applying heat, you are dilating the capillaries and allowing venom to go further into the body.”

The study was prompted by an influx of man o’ war on European coasts last summer and built upon the findings of a study on box jellyfish conducted by the University of Hawaii at Mānoa. The researchers will now turn their attention to the lion’s mane jellyfish to determine if the same conclusions apply.

(First published in The Guardian UK. Available online at: https://www.theguardian.com/environment/2017/may/09/vinegar-best-antidote-jellyfish-stings-urine-lemon-juice-make-worse-study)

Parachuting birds into long-lost territory may save them from extinction – Science magazine, May 5 2017

Saving the Spanish imperial eagle was never going to be easy. This enormous bird, which once dominated the skies above Spain, Portugal, and northern Morocco, saw its numbers drop to just 380 breeding pairs in 2014, thanks to habitat loss, poaching, poisoning from farmers and hunters, and electrocution from power lines. Now, a new study highlights a potential way of restoring eagle populations to their former glory: dropping them into long-abandoned habitat.

One common approach for bringing threatened species back from the brink is to reintroduce them to the places they were last known to live. For example, the sea eagle in Scotland—which was hunted to extinction on the Isle of Skye in 1916—was successfully reintroduced in 1975 to Rùm Island near its last known breeding ground. But not all such efforts bear fruit: When scientists tried to release the same bird to its former range in western Ireland in 2007, the newcomers fell victim to the same poisoning that had done them in 107 years earlier.

“The tendency is to think that the last place that an animal was present is the best place for the species, but this isn’t always the case,” says Virginia Morandini, a biologist with the Spanish National Research Council’s Doñana Biological Station near Seville.

So Morandini and her colleagues teamed up with conservation biologist Miguel Ferrer of the Migres Foundation at Doñana to try a different approach. Along with the Andalusian government’s Spanish Imperial Eagle Action Plan, they introduced imperial eagles into a territory they last inhabited some 50 years ago, far from established populations. Their method had some strong theoretical underpinnings because relict populations that have been pushed into small, low-quality habitats—often the “last known address” of threatened species—are thought to have relatively low breeding rates.

From 2002 to 2015, the Doñana team monitored 87 eagles that had been released in the south of Cádiz province of Spain, some 85 kilometers from the nearest established eagles. Meanwhile, the researchers monitored a naturally occurring population of eagles in south-central Spain. When scientists analyzed the breeding success of the two groups—a proxy for how well the eagles might survive over the long run—they found that the relocated population produced nearly twice as many chicks, they reported last month in Ecology and Evolution. Morandini attributes their success to the ready availability of prey and breeding partners, as well as efforts to reduce threats from hunters and exposed power lines.

The results suggest such reintroductions can be helpful in recovering endangered populations, especially when natural range expansion isn’t a possibility, says Doug Armstrong, a conservation biologist at Massey University in Palmerston North, New Zealand. But Armstrong, who was instrumental in rehabilitation efforts in New Zealand of a honeyeater-like bird called the hihi, also warns that this method won’t work for every threatened species. Lots of factors can lead to failure: selecting an inappropriate site, unpredictable environmental factors, and stress after reintroduction.

Cornell University ecologist Amanda Rodewald says that—even with its upsides—the approach should be seen as a last resort. “With ongoing climate change and habitat destruction, we are likely to be turning to [reintroduction] methods more and more,” she says. “However, taking proactive conservation steps such as habitat protection before a species becomes critically endangered is always going to be the most cost-effective and successful approach.”

(First published by Science magazine on May 5 2017. Available online at: http://www.sciencemag.org/news/2017/05/parachuting-birds-long-lost-territory-may-save-them-extinction)

Parents of children with Cystic Fibrosis bring their campaign to the Dail – Enniscorthy Guardian, December 10 2016

Ballindaggin mother Julie Forster left the Dail feeling hopeful last Thursday following a presentation to push for the funding of Cystic Fibrosis drug Orkambi.

Julie was one of 14 parents from around the country to travel to Dublin in a bid to gain government support for the drug, which they believe will improve the quality of life for their children. Armed with photographs and stories of their beloved children, the representative group made a moving presentation to TDs on the reality of living with the illness.

‘We think it went very well. It is hard to say but many of the TDs said that they were very moved,’ said Julie, whose three-year-old daughter Ruth suffers from Cystic Fibrosis. ‘We had a very good attendance which we were happy with. James Browne was the only Wexford representative that I saw but we had many more from around the country.’

Though Julie did not make a presentation herself, Riverchapel mother Claire Merrigan spoke about her son Mason, the severity of his illness and the daily routine that he must endure. Several other parents from around the country, including those whose children are currently on the Orkambi trial, also spoke about their own experiences.

‘Some of the TDs asked some questions, mainly around the Orkambi figures on improvement. We explained that, while the figures don’t always look great, the reality is that a lot of people are doing well on it and a lot of money could be saved on hospital admissions if people were on Orkambi,’ explained Julie. ‘All of them promised that they would go further with it. There is nothing definite but anyone we spoke with afterwards said that they would support us. They agreed that a solution has to be found.’

The meeting took place only days after an exclusive report was published in the Sunday Business Post stating that the HSE drug committee had recommended against funding Orkambi, which has a €159,000 annual price tag per patient. It was reported that the committee did not view the drug to deliver enough benefits to justify its high cost. Julie and many other parents and sufferers around the country learned of the news through a Tweet – something Julie described as ‘disgraceful‘.

‘We are still very disappointed with how the news came out,’ said Julie last week. ‘The HSE still haven’t made a formal statement on it but they aren’t denying it.’

However, in the days following the leak, Minister for Health Simon Harris has reached out to overseas counterparts asking them to work with him to make Orkambi available for patients at a cost-effective price. He has assured patients that the process for accessing Orkambi is not over but said that more discussions and price negotiations with manufacturer Vertex are needed.

In the meantime, the parents group will continue to fight for their cause. On December 7, they will travel to Dublin to participate in a march to the Dail.

(First published in the Enniscorthy Guardian newspaper: print edition. Also available online at: http://www.independent.ie/regionals/goreyguardian/news/parents-of-children-with-cystic-fibrosis-bring-their-campaign-to-the-dail-35270351.html)

Enniscorthy’s new social housing will be the first passive house scheme in country – Enniscorthy Guardian, December 10 2016

Enniscorthy will receive €1.5m in government funding to purchase eight new passive homes in what is the first scheme of its kind in the country.

Based in Madeira Oaks in Enniscorthy, the homes have been awarded an A minus BER rating which means that they produce more energy than they require. They were constructed by Michael Bennett of Enniscorthy Passive Developments and will cost €190,000 each.

‘In the past while, we have been looking at ways of addressing the housing supply issue and asked people with ideas to get in touch. Michael Bennett contacted us and we liked his scheme in terms of the way it uses sustainable energy, reduces the need for heating and also addresses the issue of fuel poverty,’ said Senior Executive Housing Officer Liz Hore. ‘We were delighted to get word that we will receive €1.5 m to work with him.’

These homes typically have energy costs of about €200 per year in comparison with the average household bill of €2,500. According to Ms Hore, the first two will be ready to move into in the new year.

She added that the scheme has allowed them to deliver fast-track social housing in Enniscorthy.

‘We have been discussing about the need to accelerate the delivery of social housing. These passive houses are being turned around within eight months.’

This is first time that passive homes have been acquired for social housing in Ireland. According to Ms Hore, they are hoping that their scheme will serve as a demo model for others around the country. She said that passive homes are the way forward, due to their affordability and lower fuel requirements.

‘They are ticking all of the boxes,’ she said.

(First published in the Enniscorthy Guardian newspaper: print edition. Also available online at: www.independent.ie/regionals/enniscorthyguardian/news/enniscorthys-new-social-housing-will-be-the-first-passive-house-scheme-in-country-35270416.html)

Wexford Drama Group celebrates 50 years in the spotlight – Wexford People, December 10 2016

Wexford Drama Group celebrated their 50th anniversary in theatrical fashion with a celebration in the Irish National Heritage Park recently.

The group pulled out all of the stops to ensure the night was unforgettable, with plenty of drama, music and nostalgia to keep the crowd going. Over 60 people attended the event, which marked an end to the celebrations for this year.

Mayor of Wexford Frank Staples held a Civic Reception for Wexford Drama Group at the beginning of the evening. He spoke about the history of the group and, on behalf of the people of Wexford, expressed his pride in having such an organisation in the community.

It was a nostalgic evening for many as members from years gone by joined together with current members. Three of the former members – Des Waters, Jean Gould and Noreen Colfer – were part of the original group founded 50 years ago and in honour of this, they were presented with a lifetime membership by the current members. Throughout the night, different generations of the group performed short pieces, while old memorabilia such as posters and photos were dotted around the venue. A particular highlight was a moving video featuring interviews with some of the older members, which was compiled by John Michael Murphy.

Chairperson of the group Carol Long said a few words to the crowd, as did Phil Lyons, who shared some of his memories about his years in the group. Phil was also part of the event’s organising committee, along with Aine Gannon, Hilda Conway and Paul Walsh.

To top everything off, everyone enjoyed a meal, music by Damian Nolan and plenty of dancing until the early hours.

‘It was a really great night. It was lovely to mark the occasion as people do come and go. The event got people back in touch with the group,’ said PRO of Wexford Drama Group Tom O’Leary.

The night followed on from an event in Wexford Library the previous day, during which excerpts from the group’s first play ‘The Heiress’ were performed by former and current members. The play was produced by the group back in 1966 and in honour of the occasion, original cast members Jean Gould and Noreen Colfer played their parts once more. An exhibition of photographs and memorabilia of the last 50 years was also unveiled.

Following a successful weekend, the show must go on for the drama group. The will now turn their attention to their next production ‘Portia Coughlan’ by Marina Carr which will hit the Arts Centre stage in February.

(First published in the Wexford People newspaper: print edition. Also available online at: http://www.wexfordpeople.ie/news/wexford-drama-group-celebrates-50-years-in-the-spotlight-35270067.html)

Enniscorthy mother won’t give up fight for her CF daughter – Enniscorthy Guardian, December 3 2016

News that the HSE won’t fund Cystic Fibrosis drug Orkambi is ‘devastating’ according to Julie Forster, but she is not going to let it prevent her from keeping up the fight to get access to the drug for her daughter.

At the weekend, the Sunday Business Post broke the news that the drug will be rejected for use by the HSE after their drug committee recommended against funding the drug at a recent meeting. According to the article, the committee, which includes several senior clinicians, decided it did not deliver enough benefits to patients to justify its €159,000 price tag.

Ballindaggin resident Julie Forster, whose three-year-old Ruth suffers from the illness, learned of the news through a Tweet on Saturday night, only days before she and members of a CF action group for parents will hold a presentation in the Dail to push for the funding of the drug.

‘The way it broke is just disgraceful. Members of the Cystic Fibrosis community and even Cystic Fibrosis Ireland learned of the news through a Tweet. We took that pretty hard and at first, we were wondering if it was misinformation,’ she said. ‘It just shows the way that the CF community is treated in general. Apparently Simon Harris didn’t even know about this. The fact that they went to the newspapers first is a disgrace.’

Julie said that she was ‘absolutely devastated’ to learn of the news, which according to her, has taken away a lot of hope for parents and sufferers of Cystic Fibrosis. The possibility that the drug may not be funded by the HSE would also bring the drug trials, that several people around Ireland are currently undertaking, to a halt. Though Julie’s daughter is not currently trialling Orkambi and is ‘quite well’ at the moment, she said that this could affect several families that she knows.

‘I am in touch with some families whose teenagers are on the trials and are doing really well. They have been on it for three years and can’t contemplate what life would be like if they are taken off the drug,’ she said.

Despite the huge disappointment brought by the recent news, Julie is still prepared to fight in the Dail on Thursday along with representatives from 14 other families who are affected by the illness.

‘This Thursday, we will still do our presentation and hope that we can get as many TDs as we can to back it. Simon Harris has the power to overturn the decision but he has said in the past that he wouldn’t. The drug company Vertex have issued a statement saying that they are still willing to negotiate on the price. So our options are either to negotiate on the price or make Minister Harris change his mind,’ she said. ‘We are hoping that we will come to some agreement.’

Julie has invited the five Wexford ministers to the presentation and has received responses from all of them. James Browne has promised to attend the meeting, while Mick Wallace said either he or a representative will be there. She was informed that Brendan Howlin will do his best to attend. Paul Kehoe is unavailable but has contacted the group to say that he will meet them on another date. Meanwhile, Michael D’arcy said that he could not attend.

Other members of the group nationwide have also called on their TDs to attend, while all are encouraging people to attend a separate march to the Dail on December 7.

‘We have received quite a promising response from TDs. Hopefully when they come out, they will learn more about the illness. It might help them to put faces to numbers,’ said Julie. ‘It is a matter of trying to get this funded and in my opinion, it has to be done. It is a matter of life and death to some people.’

(First published in the Enniscorthy Guardian newspaper: print edition. Also available online at: http://www.independent.ie/regionals/enniscorthyguardian/news/enniscorthy-mother-wont-give-up-fight-for-her-cf-daughter-35251969.html)