Zoology: Pretty good

Vol 453|29 May 2008 S. D. MILLER/R. VALENTIC/NATUREPL.COM RESEARCH HIGHLIGHTS Pretty good Ecology 89, 1201–1207 (2008) There is strength in diversity, say Anders Forsman and Viktor Åberg of the University of Kalmar in Sweden. The pair looked at 323 species of Australian reptile — 275 lizards and 48 snakes — and found that species that exhibit variable skin patterns have ranges almost three times larger, on average, than do reptile species with less variable colouration. They also live in more habitat types. CELL BIOLOGY D. WATTS / ALAMY Bean counting The researchers propose that multiple colour patterns reflect combinations of traits that, by evolving together, allow a single species to exploit a range of environments. Fifty of the species studied are classified as threatened, and of those to caloric restriction and SUV39H1, which can alter gene expression. Cell 133, 627–639 (2008) THEORETICAL PHYSICS A newly identified protein complex allows cells to vary the rate at which they make ribosomes — the factories that translate RNA into protein — in response to how much energy is available. Ribosome production is the most energetically expensive thing that eukaryotic cells do, so the complex has an important role in cell survival. A team led by Junn Yanagisawa of the University of Tsukuba in Japan isolated a protein complex called NoSC that controls transcription of ribosomal RNA, the main component of ribosomes, in response to the ratio of NAD+ to NADH molecules, a signal of the available energy in a cell. NoSC contains a previously uncharacterized protein, named nucleomethylin, that binds one of the histone proteins with which DNA is packaged. It also comprises SIRT1, a protein made in response Better out than in Phys. Rev. Lett. 100, 211302 (2008) Surviving a black hole is not easy, but calculations by Abhay Ashtekar of Pennsylvania State University, University Park, and his collaborators suggest that under certain conditions quantum information might make it out. This team of physicists imagines space– time as having a fundamentally quantum structure. Considered in this way, a black hole’s point of infinite mass and gravitational pull, known as its ‘singularity’, disappears, and quantum fluctuations can travel right through the black hole’s core. This result is important because it fulfills the stipulation of quantum mechanics that information is always conserved. The authors hope their work might one day help to integrate quantum mechanics with theories of gravity. GENETICS Tiger-mice PLoS One 3, e2240 (2008) DNA from the Tasmanian tiger (Thylacinus cynocephalus, a marsupial, pictured left) has been put to work inside mice, marking the first example of successful genetic transfer from an extinct species to a living one. 566 only one (the death adder, Acanthophis antarcticus) showed variable coloration (pictured). So this finding may provide conservationists trying to guage the status of littlesurveyed reptiles with a useful rule-of-thumb. Richard Behringer of the University of Texas M. D. Anderson Cancer Center in Houston and his colleagues extracted DNA from a century-old Tasmanian tiger skin and three preserved pouch young held in the Museum Victoria in Melbourne. The researchers then took a regulatory part of the Tasmanian tiger’s Col2a1 gene, which is involved in the development of bone and cartilage, and introduced this into the genomes of several mouse embryos. These modified mice grew up normally, with the inserted section of tiger-Col2a1 functioning in their developing skeletons. NANOTECHNOLOGY Nanozapped Nano Lett. doi:10.1021/nl080661a (2008) Tiny, levitating semiconductor particles can produce laser light. This happened when a group of researchers led by Lijun Wang at the University of Erlangen in Germany encased quantum dots with cadmium-selenide cores and zinc-sulphide shells in microdroplets of water and glycerine, and electrically charged the droplets to keep them floating in air. When energized with light from a laser, the encased quantum dots generated their own laser light. A microdroplet forms a super-smooth spherical capsule around the quantum dots, causing the photons they give off to oscillate at specific wavelengths, a requirement for lasing. Surprisingly, the density of quantum dots within a single microdroplet needed to produce laser light was very low, the researchers say — as was the power needed to drive the process.  (...truncated)