‘Stealing’ life’s building blocks

first_imgIn a finding that could fundamentally rewrite science’s understanding of how some parasite-host relationships work, Harvard researchers have found that, despite being separated by more than 100 million years of evolution, the parasitic “corpse flower” of Southeast Asian rain forests appears to share large parts of its genome with its hosts, members of the grapevine family.The two plants share the genome parts, researchers believe, through a process known as “horizontal gene transfer.” Horizontal transfer occurs when genes are passed between organisms without sexual reproduction, as opposed to vertical transfer, in which a parent passes genes to its offspring,As described in the June 6 issue of BMC Genomics, in a study co-led by Harvard and Stony Brook University, researchers found that this type of genetic sharing between plants is much more widespread than had been suspected, and that some genes borrowed by the flowers are likely functional, and may have replaced vertically inherited copies. The surprising finding, said Charles Davis, professor of organismic and evolutionary biology and curator of vascular plants in the Harvard University Herbaria, suggests that the process may convey some evolutionary advantage to the flowers, which are the largest in the world.“We found that several dozen actively transcribed genes likely originated from the flower’s host,” said Zhenxiang Xi, a graduate student in Davis’ lab, and first author of the paper. “In addition, we found evidence that about one-third of the parasites’ own vertically inherited genes have evolved to be more like those of hosts, suggesting that there might be a fitness benefit to maintaining genes that are more hostlike.”“At the outset, we wondered if it could be that a subset of these genes might provide some defense from the host mounting an attack,” Davis added. “However, the genes coming to the flowers represent a broad swath of functions, including respiration, metabolism, and perhaps some useful for defense. If so, these findings might reflect a sort of genomic camouflage, or genomic mimicry for the parasite.”Despite being separated by more than 100 million years of evolution, the parasitic “corpse flower” of Southeast Asian rain forests appears to share large parts of its genome with its hosts, members of the grapevine family. Photo by Charles DavisThe new paper builds on research Davis conducted in 2004, just before coming to Harvard, which focused on understanding the evolutionary origins of such “extremophiles” that thrive under conditions where most life would not.“For years, these plants have been something of an evolutionary mystery, because they simply don’t possess the genetic tool kit — primarily, the genes associated with photosynthesis — that evolutionary biologists have used to place them on the broader tree of life,” Davis said. “These plants have reduced themselves so much, they’ve actually lost many of the genes associated with photosynthesis.”Using newly developed genomic tools, he identified the plants that are the closest relatives of the enormous flowers, but also stumbled into something surprising — a single region in the flower’s genetic code that was more like its host than itself.The realization that the flowers and vines appeared to be related, Davis said, was a “eureka moment.”“These species are quite evolutionarily diverged from one another, yet they have a very close, intimate physical proximity,” he said. “The parasite literally cannot live without being inside the host. Our study was one of the first to show that parasitic systems characterized by close physical contact are an area where horizontal gene transfer is taking place.”Knowing that horizontal gene transfer was happening, however, was only part of the story. Left unanswered, he said, were questions about the magnitude of these transfers, what type of genes were moving, whether those genes were functional in the flowers, and to what extent vertically inherited genes may have been replaced by horizontally acquired ones.“Following the 2004 study, there was a great deal of momentum behind the idea that the parasite-host relationship was a hotbed of activity for horizontal gene transfer,” Davis said. “But no one had tackled this question in a broad, systematic way. Our paper was the first to hit this problem, and what we found was [that] gene transfer is indeed prevalent in these parasites, and that some of those genes are likely functional.”Davis’ research didn’t stop at the genes that the flowers adopted from their host. In examining the vertically inherited genes of the parasite — those inherited from a parent — researchers found that the molecular coding of the parasites was strikingly similar to that of its host. Put simply, he said, the flowers are “learning to speak the genetic language” of their hosts, and not simply acquiring their genes.“What we think is that the genes in the parasite are independently converging on the genetic coding of the host,” he said. “Of course, in this case, it’s more likely easier to acquire genes through horizontal gene transfer if your own genetic machinery is more like your host. But when we started to find these patterns, it amazed me. If true, it’s a pretty diabolical strategy on the part of the parasite.”last_img read more

On the Blogs: The German Transition

first_img FacebookTwitterLinkedInEmailPrint分享ChinaDialogue.net:If Angela Merkel is to win another term in Germany’s upcoming election on September 24, then winning the western state of North-Rhine/Westphalia (NRW) will be essential.NRW is the country’s most populous state, making up a fifth of the electorate. It’s also the epicentre of another political tussle: What to do about Germany’s coal sector?The state is the historic heart of Germany’s industry; an industry that is largely powered by coal. NRW sits atop Europe’s biggest lignite coal region, and despite Germany’s rapid adoption of renewables, NRW still generates 75% of its electricity from coal, making it responsible for almost 1% of global annual greenhouse gas emissions.So it’s no surprise that the Rhineland coalfields near Cologne have become a hot spot for climate activists in the past few years. Internationally, Germany is well-known for its Energiewende energy policy, a transition away from nuclear and fossil fuels to renewables. But despite the aggressive push toward renewables, coal remains central to Germany’s power supply. In recent years, electricity production from coal has hardly fallen, unlike in other developed countries such as the UK and US. In fact, lignite coal provided 23% of gross power production in 2016, and hard coal 17%.Some critics argue that coal still dominates Germany’s power generation because the country has chosen to phase-out nuclear power, with the remaining plants to shut by 2022. In the aftermath of the Fukushima disaster in Japan, around a dozen new coal plants opened in Germany.What’s missing from reports about the alleged “German coal renaissance” though is that Germany’s coal surge was part of a Europe-wide trend, and not just a reaction to the nuclear phase-out. Construction of many of the plants started long before the meltdown in Fukushima.German utilities began abandoning coal projects around 2011 for the simple reason that there was no demand for them. By then, it was clear that renewables growth had been underestimated. Investors cancelled two dozen projects. The surge in wind and solar power combined with on-going coal power production led to an oversupply of electricity. As a result, power exports hit a record high by 2016. Almost 8% of electricity generated in Germany last year was used in neighbouring countries.These developments have led to the so-called “Energiewende paradox”: Germany’s rapid development of renewable power has barely dented carbon dioxide (CO2) emissions even though electricity generated from renewables has more than replaced nuclear power.The result is that Germany’s greenhouse gas emissions actually increased in 2016, and are expected to grow even more in 2017.This begs the question: how will Germany kick its coal habit?To get back on track with climate targets, Agora Energiewend is calling for Germany to adopt an emergency “Climate Protection 2020” programme as soon as possible after the federal elections this month.And some utilities are already shutting down old coal plants for economic reasons. The power company STEAG, for instance, will decommission five coal-fired units because of low wholesale electricity prices. Other companies are hoping that a political agreement on phasing-out coal power will be sweetened by financial benefits for those shutting down plants.An EU agreement on stricter pollution standards for existing power plants starting in 2021 will also factor into plans for a phase-out. Notably, the German government voted against these stricter standards.Gerard Wynn from the Institute for Energy Economics and Financial Analysis (IEEFA) estimates that Germany has many gigawatts of coal and lignite generating capacity above the new limits. Owners are facing multiple headwinds: competition with renewables, sluggish power demand growth, and carbon emissions targets. Owners will have to decide whether to retrofit or close their plants. “Utilities may use this opportunity to close or sell certain coal plants before the new standard is implemented in 2021,” he said.Germany’s current government coalition has avoided specific discussion of a coal phase-out. But there are signs that preparations for one are underway.More: Future of Germany’s coal sector hangs on elections On the Blogs: The German Transitionlast_img read more

No need to panic buy oximeters to detect ‘happy hypoxia’, lung specialist says

first_imgThere is no need for the public to start panic buying pulse oximeters to detect “happy hypoxia”, Persahabatan Hospital lung specialist Erlina Burhan said on Wednesday.Public concerns over an unusual effect of COVID-19 called happy hypoxia – in which patients have dangerously low blood oxygen levels yet show no usual symptoms of the disease – have risen due after it was reported that two patients who died from COVID-19 in Banyumas, Central Java, experienced the symptom. Lung specialist Erlina Burhan said that happy hypoxia, also known as silent hypoxemia, could be checked by examining blood gases analysis through pulse oximeters.“We can check our blood saturation level at home by putting our finger inside the oximeter pulse, ” Erlina said in a talk show hosted by the National Disaster Mitigation Agency (BNPB) on Wednesday.However, Erlina also reminded the public that not every COVID-19 patient would experience happy hypoxia. “This doesn’t mean that people should buy pulse oximeters the way people were panic buying face masks,” she said. “Pulse oximeters are not necessary for healthy people or asymptomatic cases.”She said that those who experienced happy hypoxia usually suffered from worsening coughs and feelings of fatigue.She explained that people whose blood oxygen levels dropped would usually suffer from difficulty breathing.“However, this doesn’t happen to some COVID-19 patients [who experience happy hypoxia] because of nerve damage, which results in their brain failing to recognize the lack of oxygen,” Erlina said. (dpk)Topics :last_img read more

Friends Together and Hope Shores Alliance host benefit masquerade ball

first_imgAddThis Sharing ButtonsShare to FacebookFacebookShare to TwitterTwitterShare to MoreAddThisTwo community organizations gathered over the weekend and partied for a good cause.Friends Together and Hope Shores Alliance hosted their masquerade ball to benefit cancer patients and domestic violence victims.Event organizer, Stacy Roznowski says funds raised from this second annual event will have an immediate and lasting impact on the community.“We’re always looking to raise some money for our organizations. So for Friends Together, it’s a really big deal. The money that we raised here will help with gas cards for people to get to treatment, rides to treatment, some hotel stays…things like that. Hope Shores always needs money for their safe houses, things like that.”The night consisted of a silent auction, good food and lots of photos. Over 200 attendees showed up to the event.If you would like to donate, contact Hope Shores Alliance or Friends Together of Alpena.AddThis Sharing ButtonsShare to FacebookFacebookShare to TwitterTwitterShare to MoreAddThis Tags: ball masquerade ball, friends together, Fundraiser, Hope Shores AllianceContinue ReadingPrevious Photo of the Day for Monday, February 25Next Tip night raises over $600 for the Boys & Girls Clublast_img read more