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Saturn's moon Titan has a foggy bottom
JIM LINDSEY
IN BRIEF Fatty foods foil fat-fighting cells
‘Extinct’ British resident repatriated after 100 years A BRITISH resident transported to the Antipodes a century ago will soon be repatriated. The short-haired bumblebee was sent to New Zealand to pollinate red clover in 1875 in one of the first refrigerated ships. The bee subsequently died out in its native country: last seen in 1988, it was declared extinct in the UK in 2000. Efforts to reintroduce the bee have been thwarted by failures in captive breeding and by “bee jet lag” – the inability of long-haul bees to adapt to the sudden hemisphere shift. The situation is now urgent. New Zealand’s short-
haired bumblebees thrive on another non-native species, viper’s bugloss, but the government is about to embark on a programme to eradicate the plant. Fortunately, Czech bumblebee enthusiast Jaromír Cˇížek has at last succeeded in getting the bees to breed in captivity, by feeding captive queens exclusively with high-quality bumblebee pollen instead of honeybee pollen, as had previously been attempted. The Bumblebee Conservation Trust at the University of Stirling, UK, now plans to reintroduce the bees after breeding them up in New Zealand, refrigerating them to induce hibernation and avoid jet lag, and transporting them to the UK. The trust presented its work on the reintroduction at the British Ecological Society meeting at the University of Hertfordshire, UK, this week.
Potato blight has the genome of death THE blight that triggered the great famine in Ireland in 1845 is still the biggest disease threat to spuds worldwide – and it’s no wonder. Researchers have sequenced the genome of the mould that causes blight and found it keeps a huge arsenal of potato-destroying genes, ready to evolve around whatever defences taters can muster. On the plus side, the sequence also suggests ways to fight back. 16 | NewScientist | 12 September 2009
Blight is caused by an oomycete or water mould, Phytophthora infestans, related to brown algae. Sophien Kamoun of the Sainsbury Laboratory in Norwich, UK, and colleagues report that P. infestans has a genome three times as large as its closest relatives, because it keeps many different variants of its “attack” genes (Nature, DOI: 10.1038/nature08358). These code for enzymes that kill potato cells,
on which the mould then feasts. There are numerous variations, with many bits of DNA that jump around the genome, allowing the continual generation of more variation. This means the blight can make new enzymes as fast as potatoes evolve ways to neutralise the old ones. However, the team also found virulence genes in regions of the genome that are not so variable. “Those could be great targets for plant resistance,” Kamoun says.
HEALTHY muscle cells exposed to fat can become like cells taken from people with diabetes, with the genes that control fat-burning permanently switched off. “In essence, fat tweaks the cell’s ability to burn fat,” says Juleen Zierath of the Karolinska Institute in Stockholm, Sweden. The findings suggest that changes to DNA may occur when healthy people eat fat-rich diets, and could ultimately explain why adults develop type 2 diabetes. Zierath and her colleagues discovered that cells from people with diabetes already had these changes, especially in PGC-1, a gene that orchestrates fat burning. The researchers found that they could trigger the same effects in healthy muscle cells by exposing them to the fat palmitate. The results show that foods may reprogramme our DNA (Cell Metabolism, DOI: 10.1016/ j.cmet.2009.07.011).
Titan has a foggy bottom FOG has been spotted on Titan, the first evidence that the Earth isn’t the only body in the solar system to have a hydrological cycle. Yet Titan’s cycle is based on methane. Saturn’s moon Titan is known to have lakes, clouds and river beds, hinting that surface liquid evaporates and returns as rain. But proof is lacking: the lakes might not evaporate, the clouds might not rain, and the river beds might be relics from a wetter past. Now Michael Brown of the California Institute of Technology in Pasadena and his team have used NASA’s Cassini spacecraft to view methane fog at Titan’s south pole. The only explanation is evaporated surface methane condensing into humid air, say the team (www. arxiv.org/abs/0908.4087).
IN BRIEF Fatty foods foil fat-fighting cells
‘Extinct’ British resident repatriated after 100 years A BRITISH resident transported to the Antipodes a century ago will soon be repatriated. The short-haired bumblebee was sent to New Zealand to pollinate red clover in 1875 in one of the first refrigerated ships. The bee subsequently died out in its native country: last seen in 1988, it was declared extinct in the UK in 2000. Efforts to reintroduce the bee have been thwarted by failures in captive breeding and by “bee jet lag” – the inability of long-haul bees to adapt to the sudden hemisphere shift. The situation is now urgent. New Zealand’s short-
haired bumblebees thrive on another non-native species, viper’s bugloss, but the government is about to embark on a programme to eradicate the plant. Fortunately, Czech bumblebee enthusiast Jaromír Cˇížek has at last succeeded in getting the bees to breed in captivity, by feeding captive queens exclusively with high-quality bumblebee pollen instead of honeybee pollen, as had previously been attempted. The Bumblebee Conservation Trust at the University of Stirling, UK, now plans to reintroduce the bees after breeding them up in New Zealand, refrigerating them to induce hibernation and avoid jet lag, and transporting them to the UK. The trust presented its work on the reintroduction at the British Ecological Society meeting at the University of Hertfordshire, UK, this week.
Potato blight has the genome of death THE blight that triggered the great famine in Ireland in 1845 is still the biggest disease threat to spuds worldwide – and it’s no wonder. Researchers have sequenced the genome of the mould that causes blight and found it keeps a huge arsenal of potato-destroying genes, ready to evolve around whatever defences taters can muster. On the plus side, the sequence also suggests ways to fight back. 16 | NewScientist | 12 September 2009
Blight is caused by an oomycete or water mould, Phytophthora infestans, related to brown algae. Sophien Kamoun of the Sainsbury Laboratory in Norwich, UK, and colleagues report that P. infestans has a genome three times as large as its closest relatives, because it keeps many different variants of its “attack” genes (Nature, DOI: 10.1038/nature08358). These code for enzymes that kill potato cells,
on which the mould then feasts. There are numerous variations, with many bits of DNA that jump around the genome, allowing the continual generation of more variation. This means the blight can make new enzymes as fast as potatoes evolve ways to neutralise the old ones. However, the team also found virulence genes in regions of the genome that are not so variable. “Those could be great targets for plant resistance,” Kamoun says.
HEALTHY muscle cells exposed to fat can become like cells taken from people with diabetes, with the genes that control fat-burning permanently switched off. “In essence, fat tweaks the cell’s ability to burn fat,” says Juleen Zierath of the Karolinska Institute in Stockholm, Sweden. The findings suggest that changes to DNA may occur when healthy people eat fat-rich diets, and could ultimately explain why adults develop type 2 diabetes. Zierath and her colleagues discovered that cells from people with diabetes already had these changes, especially in PGC-1, a gene that orchestrates fat burning. The researchers found that they could trigger the same effects in healthy muscle cells by exposing them to the fat palmitate. The results show that foods may reprogramme our DNA (Cell Metabolism, DOI: 10.1016/ j.cmet.2009.07.011).
Titan has a foggy bottom FOG has been spotted on Titan, the first evidence that the Earth isn’t the only body in the solar system to have a hydrological cycle. Yet Titan’s cycle is based on methane. Saturn’s moon Titan is known to have lakes, clouds and river beds, hinting that surface liquid evaporates and returns as rain. But proof is lacking: the lakes might not evaporate, the clouds might not rain, and the river beds might be relics from a wetter past. Now Michael Brown of the California Institute of Technology in Pasadena and his team have used NASA’s Cassini spacecraft to view methane fog at Titan’s south pole. The only explanation is evaporated surface methane condensing into humid air, say the team (www. arxiv.org/abs/0908.4087).