Identification of UNC119 as a novel activator of SRC-type tyrosine kinases

Lyn, an Src-type tyrosine kinase, is associated with the interleukin (IL)-5 receptor in eosinophils. The mechanism of its activation is unknown. Through yeast two-hybrid screening we have cloned and characterized a new signaling molecule, Unc119, that associates with IL-5Ralpha and Src family tyrosine kinases. Unc119 induces the catalytic activity of these kinases through interaction with Src homology 2 and 3 domains. IL-5 stimulation of eosinophils increases Unc119 association with Lyn and induces its catalytic activity. Lyn is important for eosinophil survival. Eosinophils that are transduced with Unc119 have increased Lyn activity and demonstrate prolonged survival in the absence of IL-5. Inhibition of Unc119 down-regulates eosinophil survival. To our knowledge Unc119 is the first receptor-associated activator of Src family tyrosine kinases.     

The activation state of Rubisco directly limits photosynthesis at low CO2 and low O2 partial pressures

Using gas exchange, enzyme assays, and theoretical modeling of photosynthetic responses to light and CO₂, we investigated whether decarbamylation of the active site of Rubisco at low CO₂ and low light leads to a condition where the activation state of Rubisco directly limits the rate of net CO₂ assimilation. Photosynthetic limitation by a reduction in the activation state of Rubisco would be indicated as a decline in the initial slope of the photosynthetic CO₂ response relative to what is predicted using theoretical models. In bean (Phaseolus vulgaris) and oat (Avena sativa), we saw no discrepancy between predicted and observed initial slope values at 200 and 400 mbar O₂, indicating no limitation by the carbamylation state of Rubisco. At 30 mbar O₂ and light saturation, we also saw no discrepancy between predicted and observed initial slope values; however, at subsaturating light intensity, our observed initial slope values were less than the modeled initial slope values that corresponded to an RuBP regeneration limitation. Moreover, significant reduction of the Rubisco activation state occurred in both species at 30 mbar O₂ and 30 μbar CO₂. When the model was reprogrammed to account for observed levels of Rubisco deactivation, the predicted and measured initial slope values at low O₂ and low PPFD were similar, indicating the reduction in carbamylation state accounted for the discrepancy. We interpret this as evidence for a direct limitation of the carbamylation state of Rubisco, probably because of a CO₂ limitation for carbamate formation. This limitation was only observed at intercellular CO₂ levels below what is encountered in vivo. At physiologically relevant CO₂ levels in situ, the leaves maintained sufficient Rubisco activity to avoid cabamylation state limitations in the steady state. This revised version was published online in June 2006 with corrections to the Cover Date.     

Pollen morphology and its systematic and ecological significance in Rheum (Polygonaceae) from China

Pollen morphology of 40 species of Rheum , belonging to eight sections, was investigated under LM and SEM. Four new exine patterns were found in the species: a) microechinate-foveolate, b) rugulate, c) verrucate-perforate, and d) verrucate-rugulate ornamentation. In addition, two patterns, the Rheum-type pollens with microechinate-perforate and fine-reticulate, as previously described, were also confirmed in the present study. Based on above study the evolution trends of pollen morphology in the taxa involved were discussed phylogenetically as below. As microechinate-perforate exine pattern existed commonly, the pattern is, therefore, regarded as the most primitive among all the six types. The fine-reticulate type was thought as a derivative type, deriving from the basic microechinate-foveolate-perforate pattern, and followed by the rugulate and verrucate-perforate ornamentation. The verrucate-rugulate ornamentation should be the most advanced. More than one pollen type often exist in most of the sections in Rheum. The pollen morphology of Rheum was strongly correlated with its geographical and ecological distribution. Three medicinally important species R. officinale, R. palmatum and R. tanguticum can be palynologically distinguished by their ornamentations.     

Hypoglycemic activity of fermented mushroom of Coprinus comatus rich in vanadium.

The hypoglycemic activity of fermented mushroom of Coprinus comatus rich in vanadium (CCRV) was studied in this paper. Alloxan and adrenalin induced hyperglycemic mice were used in the study. The blood glucose and the HbA1c of the mice were analyzed, respectively. At the same time, the sugar tolerance of the normal mice was also determined. After the mice were administered (ig) with CCRV, the blood glucose and the HbA1c of alloxan-induced hyperglycemic mice decreased (p < 0.05, p < 0.01), ascension of blood glucose induced by adrenalin was inhibited (p < 0.01) and the sugar tolerance of the normal mice was improved. Also, the body weight of the alloxan-induced hyperglycemic mice was increased gradually. In the fermented mushroom of C. comatus, vanadium at lower doses in combination with C. comatus, induced significant decreases of the blood glucose and HbA1c levels in hyperglycemic mice.     

长尾小蜂科一新种—杜松大痣小蜂：膜翅目：小蜂总科

本文报道寄生杜松种子的长尾小蜂科１新种：杜松大痣小蜂Ｍｅｇａｓｔｉｇｍｕｓｒｉｇｉｄａｅｓｐ．ｎｏｖ．,模式标本存浙江农业大学植物保护系     

寄生稻纵卷叶螟的长体茧蜂属—新种记述(膜翅目:茧蜂科:长体茧蜂亚科)

本文报道寄生稻纵卷叶螟幼虫的长体茧蜂属一新种:纵卷叶螟长体茧蜂 Macrocentruscnapholocrocis,sp.nov.     

猪生长激素cDNA在芽孢杆菌中的表达

利用随机克隆的枯草杆菌启动子-信号序列构建茅孢杆菌分泌载体pUS186。用限制酶将切除了信号序列的猪生长激素cDNA从质粒pLY3-PGH 604切下,亚克隆至pUS186,并在该cDNA的下游接上地衣杆菌α-淀粉酶基因的转录终止子,构建猪生长激素表达质粒pSGH 1864,将此质粒转化蛋白酶双缺陷的枯草杆菌DB104及短小茅孢杆菌289。SDS-聚丙烯酰胺凝胶电泳检出在发酵上清液中多出一条22kD的蛋白带,抗猪生长激素血清免疫印迹法证明这一蛋白带具有免疫活性,表明猪生长激素cDNA已在枯草杆菌及短小茅抱杆菌中表达。     

人体乳腺癌细胞系Bcap－37和MCF－7的细胞遗传学研究

应用低温同步法与秋水酰胺处理,对人体乳腺癌细胞系Ｂｃａｐ－３７和ＭＣＦ－７的中期及早中期细胞进行Ｇ－显带分析。研究表明,Ｂｃａｐ－３７细胞染色体众数为６３,可识别其结构的标记染色体１７条;ＭＣＦ－７细胞染色体众数为５６,可识别其结构的标记染色体１３条。结合文献报道以及本研究结果显示,乳腺癌中最常涉及到第１、３、５、７、１１、１３和１７号染色体结构及数目的异常,染色体断裂点１ｐ１１（１ｑ１１）、１ｐ１３、３ｐ２１、３ｑ１１、５ｑ１１、６ｑ１３、６ｑ２３、７ｑ２２、１１ｐ１３和１１ｐ１５也经常涉及;它们可能与癌相关基因的激活和抗癌基因的丢失有关,从而在乳腺癌发生发展中起一定作用。