Trans—acting factors from the human fetal liver binding to the human ε—globin gene silencer

The developmental stage-specific silencing of the human ε-globin gene during embryonic life is controlled,in part,by the silencer (-392bp- -177bp) upstream of this gene.In order to elucidate its role,the nuclear extract from the human fetal liver has been prepared and the interactions between trans-acting factors and this silencer element have been examined.By using DNaseI footprinting assay,a major protected region from -278bp to -235bp within this silencer element was identified.Furthermore,we found in gel mobility shift assay and Southwestern blotting assay that there were at least four trans-acting factors (MV≈32,28,26 and 22kD) in the nuclear extract isolated from the human fetal liver,which could specifically bind to this region.Our results suggested that these trans-acting factors might play an important role in silencing the human embryonic ε-globin gene expression at the fetal stage through the interactions with this silencer.     

基于GC-MS代谢组学技术委陵菜与星毛委陵菜的初生代谢比较研究

为明确药用植物委陵菜与其同属植物星毛委陵菜在不同基原之间的代谢差异，更有效的利用药用植物资源。基于气相色谱与质谱联用技术对两药用植物间的小分子初生代谢物进行非靶向代谢组学分析，利用主成分分析和偏最小二乘法分析，寻找可区分两物种的差异代谢物以及在初生代谢途径上的差异。结果：利用GC-MS在两植物中共检测到134个色谱峰，通过与数据库比对，共鉴定出43种初生代谢产物。PCA分析结果显示代谢物在委陵菜和星毛委陵菜间的分布有较大的差异；采用OPLS-DA筛选获得导致2物种区分的差异代谢物共33种，两物种在半乳糖代谢、淀粉和蔗糖代谢、氨酰生物合成、氨基糖和核苷酸糖代谢和果糖和甘露糖代谢途径有显著的差异。委陵菜和星毛委陵菜的初生代谢方面存在较大差异，虽然两植物来源于同科同属植物，但是星毛委陵菜不适合代替委陵菜作为药材使用。     

A new oviraptorid (Dinosauria: Theropoda) from the Upper Cretaceous of Bayan Mandahu,Inner Mongolia

Abstract: A new oviraptorid is described on the basis of a partial forelimb collected from the Upper Cretaceous redbeds of Bayan Mandahu, Inner Mongolia. Machairasaurus leptonychus, gen. et sp. nov. is diagnosed by slender, weakly curved manual unguals, reduced flexor tubercles, penultimate phalanges that are subequal in length to the preceding phalanges, and short, robust manual digits. Machairasaurus is found to be a member of the Ingeniinae, along with Ingenia yanshini, Heyuannia huangi, Conchoraptor gracilis, and Nemegtomaia barsboldi. Machairasaurus exhibits unusual proportions of the manus, suggesting that the manus was not primarily used to grasp prey. Instead, Machairasaurus and other oviraptorids are likely to have fed largely on plant material. The recognition of a previously unknown oviraptorid at Bayan Mandahu provides further evidence that the Bayan Mandahu dinosaur assemblage is distinct from that found at the Djadokhta Formation exposures at Bayn Dzak, Tugriken Shireh, and Ukhaa Tolgod. Given that these localities are separated by just a few hundred kilometres and represent similar palaeoenvironments, marked differences in the fauna suggest that the Bayan Mandahu Formation of Inner Mongolia is not coeval with the known Djadokhta localities in Mongolia.