Bioscience

New HCV Cell Infection Model

In December, the Journal of Virology published online the latest achievements of Zhong Jin Research Group, Institute Pasteur of Shanghai, CAS, which mainly clarified the establishment of a new type of hepatitis C Virus cell infection model. Hepatitis C virus (HCV) is primarily spread through blood and can lead to acute and chronic hepatitis, cirrhosis and liver cancer. The lack of HCV in vitro infection model is one of the major factors to impede the research in HCV molecular biology and immunology. Dr. Li Rui, under the guidance of Prof. Zhong Jin, constructed a HCV cell model capable of producing virus-like particles with single-cycle infection. This system was based on the principle of trans-complementation, e.g. the homologous virus expressing in trans or the envelope proteins of vesicular stomatitis virus was used to package the HCV genome RNA lacking envelope protein sequences. The single-infectious HCV may truly simulate in biological characteristics the process of invasion and reproduction of real virus, which not only strengthened the existing system in studying HCV life cycle, but also provided a new way for HCV vaccine development.

Transgenic Cotton Reduces Overwintering Capacity of Heliocverpa Armigera

As one of the most serious insect pests of cotton, corn, soybeans, peanuts, vegetables, and other crops in China, helicoverpa armigeraoverwinters mainly as a pupa. Previous research indicated that Bt cotton planted widely in north China affected the growth and reproduction of helicoverpa armigeraand thereby reduced their quantity. Ge Feng Research Group of the State Key Laboratory of Integrated Management of Agricultural Pest Insects and Rodents, Institute of Zoology, CAS discovered, through indoor and field experiments, that transgenic cotton significantly reduces the pupation rate, diapause rate and emergence rate of overwintering helicoverpa armigera, decreases the pupal weight, the content of the energy reserve material glycogen and the density of the cold-resistant small molecular material trehalose both in diapausing and non-diapausing pupae, and greatly increases the supercooling points of diapausing pupae. A future study shows that transgenic cotton reduces the cold tolerance of helicoverpa armigera by decreasing the energy reserve materials in their bodies before overwintering, and thus lowers the population fitness of overwintering helicoverpa armigera and eventually causes the significant reduction of insect sources for helicoverpa armigera in the next spring. Therefore, transgenic cotton not only affects the growth and development of helicoverpa armigera in the cotton growing season, but further influences their physiological and ecological features including overwintering and diapause, and it has become one of the major factors for the helicoverpa armigera species to decrease in large areas of the northern areas of China over the past decade. The research result was published in Journal of Insect Physiology(Effects of transgenic Bt cotton on overwintering characteristics and survival of Helicoverpa armigera, 57 (2011) pp.153–160).

First Single-fingered Dinosaur Unearthed

An international paleontological survey team led by Prof. Xu Xing from the Institute of Vertebrate Palaeontology and Paleoanthropology, CAS, discovered a new species of dinosaur, the size of which is as big as a parrot, but with only one finger in its hands in the sedimentary rocks from the Upper Cretaceous Wulansuhai Formation on the border between Mongolia and China. This feature makes the specimen the only known dinosaur with one finger and highlights a complex pattern of evolution in the hands of theropods.Scientists named the small dinosaur as Linhenykus monodactylus, which represents the first single-fingered dinosaur discovered in the world. The new dinosaur belongs to Alvarezsauroidea, a family within the carnivorous dinosaurian group Theropoda. Theropods gave rise to modern birds and include famous dinosaurs such as Tyrannosaurus and Velociraptor. Linhenykus most likely grew to a few feet high and weighed only as much as a large parrot. The new theropod is unusual in having just one large claw on each of its hands, which might be used to dig out insects. The relevant work was published on the U.S. Proceedings of National Academy of Sciences (PNAS) on Jan. 24th, 2011. Linhenykus lived with closely-related and similarly-sized theropod dinosaurs, but the specializations of its skeleton may reflect differences in behavior or foraging strategy. Linhenykus also lived alongside small mammals, lizards, and clubbed (ankylosaurs) and horned dinosaurs (ceratopsians). Michael Pittman, from the Department of Earth Sciences at the University College London, co-author and discoverer of the specimen said: “Non-avian theropods start with five fingers but evolved to have only three fingers in later forms. Tyrannosaurs were unusual in having just two fingers but the one-fingered Linhenykus shows how extensive and complex theropod hand modifications really were.”