Changes in spatial distribution pattern during the larval stage of the fall webworm,Hyphantria cunea drury (Lepidoptera: Arctiidae)

Summary The changes in spatial distribution pattern during larval stage of the fall webworm,Hyphantria cunea were quantitatively investigated in the field experimental populations. The female adult deposits eggs as a cluster and the hatchlings make a compact colonial-web. In this period, the all-or-none type mortality which is characteristic in gregarious insect species was occasionary recognized before spinning a compact colonial-web. Once making a compact colonial-web, the larvae feed the leaves in the colonial-web up to about 5th instar. In this period, the movement of larvae occurred due to the local food shortage in a colonial-web and the expansion of colonial-web. As the larvae developed, the colonial-web was separated into several small groups. These larvae began to disperse about 5th instar. In this period, the local food shortage seems to be an important trigger for the larval dispersal. The mean concentration of larvae on leaves abruptly decreased, and finally the larvae became solitary at the 6th or 7th instars. The dispersal process in later larval stage is not necessarily due to the complete food shortage. The dispersal prior to the occurrence of food shortage may be a safety mechanism to protect the larvae from the food shortage.     

An N-glycan structure correlates with pulmonary metastatic ability of cancer cells

N-Glycan structures on the surface of cancer cells have diverse structures and play significant roles in metastatic process. However, little is known about their roles in organ-selective metastasis. Our study revealed that an alpha1,6-fucosylated biantennary N-glycan structure designated A2G2F is characteristic of lungs, with far more abundant expression in normal human and murine lungs than in other organs. In this study, we further examined the role of A2G2F in pulmonary metastasis. We stained metastatic cancers by alpha1,6-fucose-specific Lens culinaris agglutinin lectin and revealed that pulmonary metastatic nodules more abundantly expressed alpha1,6-fucosylated N-glycans than hepatic metastatic nodules from common primary cancers. The most specific alpha1,6-fucosylated N-glycan structure in pulmonary metastatic cancer was identified to be A2G2F. Using a B16 melanoma cell metastasis model, we showed that A2G2F-rich B16 cells formed more pulmonary metastatic nodules than A2G2F-poor cells. Our results suggest that A2G2F plays a critical role in pulmonary metastasis.     

Decoupling Analysis of Four Selected Countries

We examine decoupling conditions of domestic extraction of materials, energy use, and sulfur dioxide (SO₂) emissions from gross domestic product (GDP) for two BRIC (Brazil, Russia, India and China) countries (i.e., China and Russia) and two Organisation for Economic Co‐operation and Development (OECD) countries (Japan and the United States) during 2000–2007, using a pair of decoupling indicators for resource use (D_r) and waste emissions (D_e) and the decoupling chart, which can distinguish between absolute decoupling, relative decoupling, and non‐decoupling. We find that (1) during 2000–2007, decoupling between environmental indicators and GDP was higher in the two OECD countries as compared with the two BRIC countries. The key reason is that these countries were in different development stages with different economic growth rates. (2) Changes in environmental policies can significantly influence the degree of decoupling in a country. (3) China, Japan, and the United States were more successful in decoupling SO₂ emissions from GDP than in decoupling material and energy use from GDP. The main reason is that, unlike resource use, waste emissions (e.g., SO₂ emissions) can be reduced by effective end‐of‐pipe treatment. (4) The decoupling indicator is different from the changing rate of resource use and waste emissions. If two countries have different GDP growth rates, even though they may have similar values using the decoupling indicator, they may show different rates of change for resource use and waste emissions.     

In vitro neuroprotective action of recombinant rat erythropoietin produced by astrocyte cell lines and comparative studies with erythropoietin produced by Chinese hamster ovary cells

In the central nervous system, astrocytes produce erythropoietin (Epo) and neurons express its receptor. To examine whether or not the brain Epo protects the in vitro cultured neurons from glutamate-induced cell death, we established rat astrocyte cell lines containing the plasmid for production of recombinant rat Epo. Epo partially purified from the culture medium showed a neuroprotective effect similar to that of rat Epo produced by Chinese hamster ovary (CHO) cells. Comparison was made in some other properties between Epo produced by these astrocyte cell lines and that by CHO cells. Digestion of Epo with glycosidases indicated that there was a little difference in glycosylation of Epo produced by two types of the cells. This revised version was published online in July 2006 with corrections to the Cover Date.     

Does endothelin-1 participate in the exercise-induced changes of blood flow distribution of muscles in humans?

Maeda, Seiji, Takashi Miyauchi, Michiko Sakane, MakotoSaito, Shinichi Maki, Katsutoshi Goto, and Mitsuo Matsuda. Does endothelin-1 participate in the exercise-induced changes of blood flowdistribution of muscles in humans? J. Appl.Physiol. 82(4): 1107-1111, 1997.Endothelin-1(ET-1) is an endothelium-derived potent vasoconstrictor peptide thatpotentiates contractions to norepinephrine in human vessels. Wepreviously reported that the circulating plasma concentration of ET-1is significantly increased after exercise (S. Maeda, T. Miyauchi, K. Goto, and M. Matsuda. J. Appl.Physiol. 77: 1399-1402, 1994). Tostudy the roles of ET-1 during and after exercise, we investigatedwhether endurance exercise affects the production of ET-1 in thecirculation of working muscles and nonworking muscles. Male athletesperformed one-leg cycle ergometer exercise of 30-min duration atintensity of 110% of their individual ventilatory threshold. Plasmaconcentrations of ET-1 in both sides of femoral veins (veins in theworking leg and nonworking leg) and in the femoral artery (artery inthe nonworking leg) were measured before and afterexercise. The plasma ET-1 concentration in the femoralvein in the nonworking leg was significantly increased after exercise,whereas that in femoral vein in the working leg was not changed. Thearteriovenous difference in ET-1 concentration was significantlyincreased after exercise in the circulation of the nonworking leg butnot of the working leg, which suggests that the production of ET-1 wasincreased in the circulation of the nonworking leg by exercise. Thepresent study also demonstrated that the plasma norepinephrineconcentrations were elevated by exercise in the femoral veins of boththe working and nonworking legs, suggesting that the sympathetic nerveactivity was augmented in both legs during exercise. Therefore, thepresent study demonstrates the possibility that the increase inproduction of ET-1 in nonworking muscles may cause vasoconstriction andhence decrease blood flow in nonworking muscles through its directvasoconstrictive action or through an indirect effect of ET-1 toenhance vasoconstrictions to norepinephrine and that these responsesmay be helpful in increasing blood flow in workingmuscles. We propose that endogenous ET-1 contributes tothe exercise-induced redistribution of blood flow in muscles.

     

Intraspecific groups of Umbelopsis ramanniana inferred from nucleotide sequences of nuclear rDNA internal transcribed spacer regions and sporangiospore morphology

Umbelopsis ramanniana is a well-known species in this genus. A characteristic morphological feature of this fungus is the remarkable variation in the sporangiospore shape, which implies the genetic variations occur in the nucleotide sequences of the internal transcribed spacer (ITS) regions of the nuclear ribosomal DNA (nrDNA) in the U. ramanniana isolates. The relationship between the variations of the sequences of the nrDNA ITS regions and those of the sporangiospore morphology was investigated for 12 isolates of U. ramanniana collected in Europe. Neighbor-joining and parsimony analyses on the sequences suggested that these isolates split into three groups. Precise examination of the morphology showed that the isolates of those respective groups were different from each other in their sporangiospore shape. The present study implies at least three intraspecific groups exist in U. ramanniana and that the variations in the nucleotide sequences of the nrDNA ITS regions correlate well with those in the sporangiospore shape in these intraspecific groups.     

The interaction of JRAB/MICAL-L2 with Rab8 and Rab13 coordinates the assembly of tight junctions and adherens junctions

The assembly of tight junctions (TJs) and adherens junctions (AJs) is regulated by the transport of integral TJ and AJ proteins to and/or from the plasma membrane (PM) and it is tightly coordinated in epithelial cells. We previously reported that Rab13 and a junctional Rab13-binding protein (JRAB)/molecule interacting with CasL-like 2 (MICAL-L2) mediated the endocytic recycling of an integral TJ protein occludin and the formation of functional TJs. Here, we investigated the role of Rab13 and JRAB/MICAL-L2 in the transport of other integral TJ and AJ proteins claudin-1 and E-cadherin to the PM by using a Ca(2+)-switch model. Although knockdown of Rab13 specifically suppressed claudin-1 and occludin but not E-cadherin transport, knockdown of JRAB/MICAL-L2 and expression of its Rab13-binding domain (JRAB/MICAL-L2-C) inhibited claudin-1, occludin, and E-cadherin transport. We then identified Rab8 as another JRAB/MICAL-L2-C-binding protein. Knockdown of Rab8 inhibited the Rab13-independent transport of E-cadherin to the PM. Rab8 and Rab13 competed with each other for the binding to JRAB/MICAL-L2 and functionally associated with JRAB/MICAL-L2 at the perinuclear recycling/storage compartments and PM, respectively. These results suggest that the interaction of JRAB/MICAL-L2 with Rab8 and Rab13 coordinates the assembly of AJs and TJs.     

Identification of five phospho-beta-glycosidases from Lactobacillus gasseri ATCC33323T cultured in lactose medium

Lactobacillus gasseri ATCC33323(T) has seven putative phospho-beta-glycosidase genes. Using column chromatography, we found that this strain cultured in lactose medium expresses five phospho-beta-glycosidases (LacG1, LacG2, Pbg1, Pbg2, and Pbg3), where these gene expressions can be suppressed by glucose. To our knowledge, this is the first report indicating that five glycosidases are induced from a single bacterial strain using a single carbon source, lactose.