Trans-epoxide hydrolase: A key indicator enzyme for herbivory in arthropods

Summary An epoxide hydrolase selective for a trans-epoxide substrate is more commonly associated with arthropod herbivory than is a cis-selective epoxide hydrolase. The distinct selectivities in epoxide hydrolase activities between herbivorous pests and entomophagous arthropods used in their biological control may aid design of integrated pest management systems.We thank E.G. Grafius, F. Matsumura, J.R. Miller, K.L. Strickler and S.G. Wellso together with M.E. Whalon and D. Young at Michigan State University for insects and aid in identification respectively. T.L. Burger, Sr. and D. Perkins, both of the USDA, also supplied insects, and the NSF (DAR-8011600) provided support. R. Feyereisen and D. Vincent of the Department of Entomology, Oregon State University provided helpful commentary. C.A. Mullin is presently at the Pesticide Research Laboratory, Department of Entomology, The Pennsylvania State University, University Park, PA, 16802, USA. This is paper No. 10926 of the Mich. Agric. Exp. Stn and No. 6790 of the Oregon Agric. Exp. Stn journal series.     

Sodium-dependent uptake of inorganic phosphate by the intracellular malaria parasite

As the malaria parasite, Plasmodium falciparum, grows within its host erythrocyte it induces an increase in the permeability of the erythrocyte membrane to a range of low-molecular-mass solutes, including Na+ and K+ (ref. 1). This results in a progressive increase in the concentration of Na+ in the erythrocyte cytosol. The parasite cytosol has a relatively low Na+ concentration and there is therefore a large inward Na+ gradient across the parasite plasma membrane. Here we show that the parasite exploits the Na+ electrochemical gradient to energize the uptake of inorganic phosphate (P(i)), an essential nutrient. P(i) was taken up into the intracellular parasite by a Na+-dependent transporter, with a stoichiometry of 2Na+:1P(i) and with an apparent preference for the monovalent over the divalent form of P(i). A P(i) transporter (PfPiT) belonging to the PiT family was cloned from the parasite and localized to the parasite surface. Expression of PfPiT in Xenopus oocytes resulted in Na+-dependent P(i) uptake with characteristics similar to those observed for P(i) uptake in the parasite. This study provides new insight into the significance of the malaria-parasite-induced alteration of the ionic composition of its host cell.     

Systematic meta-analyses of Alzheimer disease genetic association studies: the AlzGene database

The past decade has witnessed hundreds of reports declaring or refuting genetic association with putative Alzheimer disease susceptibility genes. This wealth of information has become increasingly difficult to follow, much less interpret. We have created a publicly available, continuously updated database that comprehensively catalogs all genetic association studies in the field of Alzheimer disease (http://www.alzgene.org). We performed systematic meta-analyses for each polymorphism with available genotype data in at least three case-control samples. In addition to identifying the epsilon4 allele of APOE and related effects, we pinpointed over a dozen potential Alzheimer disease susceptibility genes (ACE, CHRNB2, CST3, ESR1, GAPDHS, IDE, MTHFR, NCSTN, PRNP, PSEN1, TF, TFAM and TNF) with statistically significant allelic summary odds ratios (ranging from 1.11-1.38 for risk alleles and 0.92-0.67 for protective alleles). Our database provides a powerful tool for deciphering the genetics of Alzheimer disease, and it serves as a potential model for tracking the most viable gene candidates in other genetically complex diseases.     

L-gulonolactone oxidase is present in the invertebrate,Limulus polyphemus

Summary L-Gulonolactone oxidase (EC 1.1.3.8) which catalyzes oxidation of L-gulonolactone to L-ascorbic acid was detected in tissues ofLimulus polyphemus.     

Caudal distraction by rat snakes (Colubridae, Elaphe ): a novel behavior used when capturing mammalian prey

Caudal movement in snakes may serve either a predatory (e.g., caudal luring) or defensive (eg., rattling, aposematism) function. I describe a new behavioral pattern of tail movement in snakes. Gray rat snakes ( Elaphe obsoleta spiloides ) foraging on small mammals ( Mus domesticus ) moved their tails in an erratic, whiplike fashion after detecting their prey in the vicinity. The thrashing movement in the horizontal plane was audibly and visually obvious, resulting in displacement of leaf litter around the tail. All subjects displayed the behavior, but not in all foraging episodes. Shorter durations of caudal distraction resulted in greater predator success during the 1st attempt at prey capture. Caudal distraction may facilitate prey capture by gray rat snakes by direction the attention of prey away from the approaching head of the snake.     

一种新型高价锰取代的多金属氧酸盐合成、结构及性质研究

在含有MnⅡ的夹心型多金属氧酸盐水溶液中加入强氧化剂KMnO4,制得一种新型的含有MnⅢ的多金属氧酸盐K5Na3[{MnⅢ(H2O)}2(WO)(H2O) (AsW9O33)2]·18H2O (KNa-1).该化合物的多阴离子结构是基于2个B-α-[AsW9]三缺位Keggin型构筑单元,中间夹着2个{MnⅢ(H2O)}和1个{WⅥO}片段而构成的夹心式构型.对KNa-1进行了变温磁化率测定并采用双核MnⅢ簇为模型进行了拟合,并对该化合物进行了电化学分析.结果表明:KNa-1 中的2个MnⅢ中心存在弱的反铁磁相互作用;化合物中的MnⅢ离子具有不可逆的氧化还原过程.