Mushroom relations

first_imgHarvard researchers are using one of the most comprehensive fungal “family trees” ever created to unlock evolutionary secrets.As reported in PLoS ONE on July 18, Associate Professor of Organismic and Evolutionary Biology Anne Pringle and Ben Wolfe, a postdoctoral fellow at the Faculty of Arts and Sciences (FAS) Center for Systems Biology, studied the genetics of more than 100 species of Amanita mushrooms — about one-sixth of the genus’s total diversity — to create an elaborate phylogeny showing how they are related.Amanita mushrooms have appeared in popular culture ranging from “Fantasia” to the Super Mario Bros. video games. Although it includes a number of edible species, such as the Amanita caesarea, the group is probably best known for its many toxic species, including the death-cap mushroom.Armed with the Amanita family tree, Pringle and Wolfe were able to determine that Amanita evolution has largely been away from species that help decompose organic material and toward those that live symbiotically on trees and their roots. More interestingly, they found that the transition came at a steep price — the loss of the genes associated with breaking down cellulose.“There had been earlier suggestions that this type of gene loss might be taking place, but our study is the first precise test of that hypothesis,” Pringle said. “The idea makes sense: If you’re going to actively form a cooperative relationship with a tree, you probably shouldn’t simultaneously be trying to break it apart and eat it. But it’s a very tricky dance to form these kinds of tight, cooperative interactions, and I think this work shows there is a cost associated with that. You have to change, you have to commit, and it can become a sort of gilded cage — these mushrooms are very successful, but they’re stuck where they are.”Amanita, however, isn’t the only mushroom to form such partnerships.“A number of mushrooms — truffles, chanterelles, and porcini — have figured out how to form these symbiotic relationships with trees,” Wolfe said. “The current thinking is that gene loss is a hallmark of the transition to symbiosis. Amanita is simply the first group we’ve been able to make that determination in because we have a phylogeny with this level of resolution.”That resolution was largely the result of Wolfe’s dedicated collecting work. In addition to many species housed in the Farlow Herbarium, at the Harvard University Herbaria, Wolfe spent months on the road tracking rare species.“Because we wanted to make sure we had a well-sampled family history, I spent a lot of time in the field collecting samples,” said Wolfe, whose stops included London and Hawaii. “The tricky part is that many Amanita mushrooms are extremely rare — in some cases, these species had only been collected once or twice in the last 50 or 60 years — and there are relatively few people with the expertise to distinguish one species from another.”Luckily, Wolfe was able to turn to one such expert — retired Bell Labs engineer Rod Tulloss, now an independent researcher and expert on Amanita mushrooms. Tulloss, whose collection of thousands of Amanita samples is stored in his New Jersey garage, which he years ago converted into a herbarium, is a co-author of the paper. As part of the research, he provided a number of crucial samples to fill out Wolfe and Pringle’s phylogeny.After extracting DNA from the samples, Wolfe used the codes of four different genes to determine how the various species are related. He then used a process called ancestral state reconstruction to show that the mushrooms have switched from being decomposers to being symbiotic with trees only once in their evolutionary history. Once the mushrooms switched to this new symbiotic lifestyle, they didn’t go back to their free-living past.Going forward, research will include studies of the entire genome of several Amanita species in an effort to better understand how symbiosis emerged, and how the mushrooms and trees maintain their partnership.Ultimately, Pringle said, the paper highlights one reason she finds such symbiotic partnerships “intrinsically interesting” — for all their apparent benefits, the cost can be high.“I think the really interesting thing is this idea that once you become symbiotic, some of your machinery is lost,” she said. “It seems like a dead end in some ways — you have to make this change to enter this niche, but once you’re there, you can’t go back — you’ve lost the capacity to be free-living.”last_img read more

Madrid Hope to Extend Lead

first_imgIn that game, Karim Benzema scored the opening for Real in the 7th minute, but around the half-hour mark, Merino Zuloaga netted a wonderful team goal to bring parity in the scoreline.Real was looking for inspiration towards the talisman Cristiano Ronaldo, but the Portuguese star was well below his best on the night and could not inject life into the flat Real attack. But just seven minutes from the normal time, Alvaro Morata, who, despite coming as a substitute, sent Gareth Bale’s cross into the back of the net and won the game for his side.Zinedine Zidane’s team has struggled heavily this season, and the Frenchman soon had to figure out the solutions for the difficulties of his team if Real Madrid wants to challenge for major honors this season.However, the Spanish league is off to a tight race atop the standings, with five teams separated by only three points. Yet, most of the talk entering the weekend is about whether  Ronaldo will end his scoring slump.Real Madrid leads the league ahead of its match at Alaves today, but no thanks to Ronaldo’s recent performances. The forward is enduring his worst start to a season since joining Madrid in 2009, having scored only four goals in nine matches.”When you’re used to scoring almost 70 goals a season, it’s almost like an addiction for goals,” Madrid reserve forward Alvaro Morata said. ”For us, he is the most important player in the team and I hope that he scores lots of goals, but he is not a machine. He is a human being. Even if he comes from another planet and is different, he also has the right to miss.”Ronaldo also scored five goals in two games with Portugal, against Andorra and the Faeroe Islands in World Cup qualifying, but that’s no reprieve to the demanding Madrid fans.He was jeered by the crowd at the Santiago Bernabeu Stadium after another disappointing performance in a 2-1 win against Athletic Bilbao on Sunday.”The fans demand a lot of players,” Madrid coach Zinedine Zidane said. ”The Bernabeu is special and we know it. Cristiano knows it and he is used to it. The important thing is to continue with our work.”Ronaldo has scored only two goals in the Spanish league – in a 5-2 win against Osasuna in September and a 6-1 rout at Real Betis two weeks ago. He also scored two goals in the Champions League, one in a 2-2 draw at Borussia Dortmund and one in a 2-1 win over Sporting Lisbon, when his free-kick goal started a late rally.”Of course he wants to score more,” Madrid defender Marcelo said. ”He is a player who helps a lot and not only with goals, also with his work on the pitch.”The game against Osasuna was the first of the season for Ronaldo. He hadn’t played since injuring his left knee in the final of the European Championship, which Portugal won. Ronaldo seems fit and has had plenty of scoring chances, but has not been able to capitalise on them – including on some he usually converts. Zidane says he is not worried and that it’s just a matter of time before he starts finding the net again.The 31-year-old was among the Madrid players rested in the team’s 7-1 win over Cultural Leonesa in the Copa del Rey on Wednesday. He is set to return to the lineup on Saturday, when Zidane’s team tries to defend its Spanish league lead against promoted Alaves.Sevilla, one point behind Madrid, plays at Sporting Gijon today, while third-place Barcelona hosts last-place Granada in its 1,500th game at the Camp Nou. Contrary to Ronaldo, Barcelona’s Lionel Messi is enjoying one of the best starts of his career with 14 goals in 11 matches. He has more goals than Ronaldo, Gareth Bale and Karim Benzema combined.Fourth-place Villarreal plays at Eibar on Sunday, and fifth-place Atletico Madrid, which led the league entering the last round, hosts Malaga today.Share this:FacebookRedditTwitterPrintPinterestEmailWhatsAppSkypeLinkedInTumblrPocketTelegram • Concern over Ronaldo as goal drought persistsDeportivo Alaves will host Real Madrid in one of the La Liga matches as the league leader look to extend its lead at the top of the table, but all eyes will be on the Los Blancos talisman- Cristiano Ronaldo, as scoring slump continuesAthletic Bilbao was the last team Real Madrid faced in the league, and the Madrid side won that game, thanks to a late goal from Alvaro Morata. The game was far from easy for Los Blancos, as it struggled to find a way through a resolute Athletic defense.last_img read more