Oligosaccharides on cathepsin D from porcine spleen

Cathepsin D from porcine spleen contained mannose (3.3%), glucosamine (1.4%), and mannose 6-phosphate (0.08%). Essentially all of the oligosaccharides of cathepsin D could be released by endo-β-N-acetylglucosaminidase H, pointing to oligomajmoside types of structures. Three neutral oligosaccharide fractions, containing 5, 6, and 7 mannose residues, respectively, were isolated by gel permeation chromatography on Bio-Gel P-2. Studies using exoglycosidase digestions and 500-MHz ¹H NMR spectroscopy revealed that their structures are [Manα1 → 2]_{0 or 1}Manα1 → 6[Manα1 → 3]Manα1 → 6[(Manα1 → 2)_{0 or 1}Manα1 → 3]Manβ1 → 4GlcNAcβ1 → 4 GlcNAc. These structures are identical to what have recently been proposed by Takahashi et al. for the major oligosaccharide units of cathepsin D from the same source (T. Takahashi P.G. Schimidt, and J. Tang (1983)J. Biol. Chem.258, 2819–2930), except for the occurrence of two isomeric oligosaccharides containing six mannoses. Only a part (3.4%) of the oligosaccharides were acidic, containing phosphates in monoester linkage. The phosphorylated oligosaccharides also consisted of oligomannoside-type chains which were analogous to, but more heterogeneous in size than the neutral oligosaccharides. Cathepsin D was bound to a mannose- and N-acetylglucosamine-specific lectin (mannan-binding protein) isolated from rabbit liver with the K_i value of 5.4 × 10^?6m.     

Two new records of the genus Cryptaphis Hille Ris Lambers (Hemiptera: Aphididae) from Korea

The genus Cryptaphis Hille Ris Lambers 1947 is described for the first time in Korea with new records of two species, Cryptaphis geranicola (Shinji 1935) and Cryptaphis menthae Takahashi 1961. Cryptaphis geranicola was collected from Geranium thunbergii (Lamiaceae) and C. menthae was collected from Isodon inflexus (Lamiaceae). Important characteristics are re-described, illustrated, and measured in apterous and alate viviparous females.     

竹类植物叶片上八种蚜虫的形态变异分析

选取寄生于竹类植物叶片上的3科6属共8种蚜虫,即居竹舞蚜Astegopteryx bambusifoliae Takahashi、小舞蚜Astegopteryx minuta (van der Goot)、居竹坚蚜Cerataphis bambusifoliae Takahashi、林栖粉角蚜Ceratovacuna silvestrii (Takahashi)、塔毛角蚜Chaitoregma tattakana (Takahashi)、竹色蚜Melanaphis bambusae (Fullaway)、竹纵斑蚜Takecallis arundinariae (Essig)和竹梢凸唇斑蚜 Takecallis taiwanus (Takahashi),在光学显微镜下观察并测量了34个形态特征;统计比较了28个形态特征在种内的变异。通过主成分分析筛选形态特征,每两两特征对应统计作图,标出每种蚜虫的95％椭圆置信区间进行分析。结果表明,体形、腹管和触角的形态在不同的科间有较大差别,喙末端、跗节Ⅰ、跗节Ⅱ及爪的形态在科间有较高的趋同性;在种内各形态特征存在一定变异,其中喙末端 （CV=3.73%～7.59%）、跗节Ⅰ （CV=4.16%～12.05%）、跗节Ⅱ （CV=3.10%～8.39%）和爪（CV=2.60%～11.68%）的变异都很小。主成分分析筛选的第一主成分为喙末端、跗节Ⅰ、跗节Ⅱ和爪,不同的椭圆区间范围提示这些特征组合基本处于稳定的范围内。与蚜虫的取食行为和附着于植物表面相关的形态特征,如喙末端、跗节Ⅰ、跗节Ⅱ和爪等在不同类群间存在显著的相似性,暗示了寄生于竹类植物叶片的蚜虫在这些形态特征上的趋同适应。最后结合蚜虫的生物学信息,初步探讨了形态适应的机制。     

Milk-clotting enzymes produced by culture of Bacillus subtilis natto

Factors affecting the production of milk-clotting enzyme (MCE) by Bacillus subtilis (natto) Takahashi, a ready available commercial natto starter, were studied. Remarkable milk-clotting activity (MCA), 685.7 SU/ml or 12,000 SU/g, was obtained when the bacteria were cultivated in the medium containing sucrose (50 g/L) and basal salts at pH 6, 37 °C with shaking at 175 rpm for 1 day. The MCA and MCA/PA ratio of the crude enzyme obtained are comparable with those of Pfizer microbial rennin and Mucor rennin. The crude enzyme showed excellent pH and thermal stability; it retained 96% of MCA after incubation for 40 min at 40 °C and retained more than 80% of its activity between pH 4 and pH 7 for more than 30 min at 30 °C. The MCE of B. subtilis (natto) Takahashi has potential as calf rennet substitutes.     

Thermal Acclimation of the Symbiotic Alga Symbiodinium spp. Alleviates Photobleaching under Heat Stress

A moderate increase in seawater temperature causes coral bleaching, at least partially through photobleaching of the symbiotic algae Symbiodinium spp. Photobleaching of Symbiodinium spp. is primarily associated with the loss of light-harvesting proteins of photosystem II (PSII) and follows the inactivation of PSII under heat stress. Here, we examined the effect of increased growth temperature on the change in sensitivity of Symbiodinium spp. PSII inactivation and photobleaching under heat stress. When Symbiodinium spp. cells were grown at 25°C and 30°C, the thermal tolerance of PSII, measured by the thermal stability of the maximum quantum yield of PSII in darkness, was commonly enhanced in all six Symbiodinium spp. tested. In Symbiodinium sp. CCMP827, it took 6 h to acquire the maximum PSII thermal tolerance after transfer from 25°C to 30°C. The effect of increased growth temperature on the thermal tolerance of PSII was completely abolished by chloramphenicol, indicating that the acclimation mechanism of PSII is associated with the de novo synthesis of proteins. When CCMP827 cells were exposed to light at temperature ranging from 25°C to 35°C, the sensitivity of cells to both high temperature-induced photoinhibition and photobleaching was ameliorated by increased growth temperatures. These results demonstrate that thermal acclimation of Symbiodinium spp. helps to improve the thermal tolerance of PSII, resulting in reduced inactivation of PSII and algal photobleaching. These results suggest that whole-organism coral bleaching associated with algal photobleaching can be at least partially suppressed by the thermal acclimation of Symbiodinium spp. at higher growth temperatures.Reef-building corals harbor symbiotic dinoflagellate algae of the genus Symbiodinium. Corals generally show a brownish coloration due to algal photosynthetic pigments, such as peridinin and chlorophylls a and c₂ present in in situ Symbiodinium spp. However, under increased seawater temperatures, corals become pale through the loss of Symbiodinium spp. cells and/or the loss of photosynthetic pigments of in situ Symbiodinium spp. (Glynn, 1993, 1996; Hoeghguldberg, 1999; Fitt et al., 2001; Coles and Brown, 2003). This phenomenon is so-called coral bleaching. Since a healthy algae-coral symbiotic relationship is important for coral survival (Yellowlees et al., 2008), severe coral bleaching leads to the mortality of corals and even the destruction of entire coral reef ecosystems. The frequency and intensity of coral bleaching have been increasing since the early 1980s, and it is predicted to become more severe in the future due to ongoing global climate change and warming (Hughes et al., 2003). Coral reef ecosystems are in serious decline, with an estimated 30% already severely damaged, and it is predicted that globally as much as 60% of the world’s coral reef ecosystems may be lost by 2030 (Hughes et al., 2003).Coral bleaching caused by heat stress is at least partially attributed to the photobleaching of photosynthetic pigments in Symbiodinium spp. within corals (Kleppel et al., 1989; Porter et al., 1989; Fitt et al., 2001; Takahashi et al., 2004; Venn et al., 2006). The photobleaching commonly occurs in photosynthetic organisms under conditions where the absorbed light energy for photosynthesis is in excess of the capacity to use it, particularly under environmental stress conditions in high light (Niyogi, 1999). In cultured Symbiodinium spp. cells, heat stress-associated algal photobleaching is attributed to the loss of major light-harvesting proteins, such as the peridinin-chlorophyll a-binding proteins and the chlorophyll a-chlorophyll c₂-peridin protein complexes (Takahashi et al., 2008). A recent study has also demonstrated that the heat stress-associated loss of light-harvesting proteins in Symbiodinium spp. is attributed to suppression of the de novo synthesis of light-harvesting proteins but not acceleration of the photodamage and subsequent degradation of light-harvesting proteins (Takahashi et al., 2008). High-temperature sensitivity of Symbiodinium spp. cells to photobleaching differs among Symbiodinium spp., and this is at least partially attributed to the thermal sensitivity of the de novo synthesis of light-harvesting proteins (Takahashi et al., 2008).Heat stress-associated photobleaching in Symbiodinium spp. follows severe photoinhibition of PSII (Takahashi et al., 2008). The extent of photoinhibition is a result of the dynamic balance between the rate of photodamage to PSII and the rate of its repair. In plants and green algae, the PSII repair process is primarily composed of the degradation and the de novo synthesis of the D1 proteins in photodamaged PSII protein complexes (Aro et al., 1993; Takahashi and Murata, 2008; Takahashi and Badger, 2011). However, this differs in Symbiodinium spp., in that the photodamaged PSII can be repaired without the de novo synthesis of D1 proteins (Takahashi et al., 2009b). Furthermore, a part of photodamaged PSII is repaired without protein synthesis (Takahashi et al., 2009b), indicating that Symbiodinium spp. have a unique PSII repair mechanism. In Symbiodinium spp. found within corals and also in culture, heat stress accelerates photoinhibition at least partially through the suppression of PSII repair (Warner et al., 1999; Takahashi et al., 2004, 2009b). However, the sensitivity of PSII repair to heat stress differs among Symbiodinium spp. and is strongly related to the sensitivity of PSII to photoinhibition under heat stress (Takahashi et al., 2009b).The high-temperature sensitivity of corals to bleaching is changed by their growth temperature, and this is suggested to be due to changing in situ Symbiodinium spp. populations from heat-sensitive to heat-resistant ecotypes (Baker, 2001, 2003; Baker et al., 2004; Berkelmans and van Oppen, 2006; Jones et al., 2008; Jones and Berkelmans, 2010). However, thermal tolerance of the population might also be enhanced by thermal acclimation mechanism(s) associated with both the corals and Symbiodinium spp., although experimental data that directly support this hypothesis are lacking. In this study, we examine the effect of increased growth temperature (thermal acclimation treatment) on the extent of heat stress-associated algal photobleaching using cultured Symbiodinium spp. Our results demonstrate that Symbiodinium spp. commonly have thermal acclimation mechanisms that enhance the high-temperature tolerance of PSII and alleviate heat stress-associated photobleaching. Our results strongly suggest that thermal acclimation of Symbiodinium spp. plays a role in alleviating algal photobleaching-associated coral bleaching under heat stress.     

Life cycles of 17 riffle-dwelling mayfly species (Baetidae,Heptageniidae, and Ephemerellidae) in central Japan

We described the life cycles of 17 riffle-dwelling mayfly species in a central Japanese stream. Both species of Baetidae (Alainites yoshinensis Gose and Baetis thermicus Uéno) and two of nine species of Heptageniidae (Ecdyonurus scalaris Kluge and Epeorus latifolium Uéno/l-nigrus Matsumura) in this stream were multivoltine (more than one generation per year). Seven other heptageniid species (two unidentified species of Cinygmula, Epeorus aesculus Imanishi, E. curvatulus Matsumura, E. ikanonis Takahashi, E. napaeus Imanishi, and Rhithrogena japonica Uéno) and all six species of Ephemerellidae [Cincticostella elongatula (McLachlan), C. nigra (Uéno), Drunella basalis (Imanishi), D. ishiyamana Matsumura, D. sachalinensis (Matsumura), and D. trispina (Uéno)] were essentially univoltine.     

Host--virus interactions in the control of T4 prereplicative transcription. I. tabC (rho) mutants.

In this paper we describe properties of old (Takahashi, 1978) and new tabC^ts and tabC^cs bacterial mutants. We find that under non-permissive conditions they differently inhibit the synthesis of specific T4 prereplicative gene products. Among such products, that we have been able to identify, are P43 and PrIIA. In contrast, P32 and PrIIB are not affected.Inhibition of P43 (T4 DNA polymerase) synthesis is sufficient to account for depressed DNA synthesis in tabC (Takahashi, 1978).In heterodiploids: (1) all tabC mutants are recessive; (2) all tabC mutants do not complement with each other; (3) at least one, tabC^ts-5521, becomes dominant at 42.6 °C if rho mutant ts15 (Tab⁺) (Das et al., 1976) is situated in trans; (4) tabC^ts-5521 also becomes dominant at 42.6 °C if tabC^cs-110 and tabC^cs-18 are situated in trans (42.6 °C is non-permissive for T4 development on tabC^cs-5521 and permissive for T4 development on tabC^cs mutants).We discuss the possibility that in tabC mutants rho protein is altered and insensitive to T4-specific anti-termination functions. We also discuss a model that accounts for the differential effect of tabC mutants on the synthesis of T4 prereplicative proteins.     

Fossil wood flora of the early Miocene Nawamata formation of Monzen,Noto Peninsula,central Japan

Silicified wood collected from the Lower Miocene Nawamata Formation at two localities, Nakaya and Nigoriike, Monzen-machi, Noto Peninsula, central Japan, were identified. Among the 58 specimens there are two species of conifers and eleven species of dicotyledons:Taxodioxylon cunninghamioides (Watari) Watari andT. sequoianum (Merckl.) Gothan (both Taxodiaceae),Carya protojaponica Watari (Juglandaceae),Pterocarya rhoifolia Siebold et Zucc. (Juglandaceae),Ostrya monzenensis sp. nov. (Betulaceae),Quercus anataiensis (Watari) Watari (Fagaceae),Liquidambar hisauchii comb. nov. (Hamamelidaceae),Prunus iwatense (Watari) Takahashi et Suzuki (Rosaceae),Gleditsia paleojaponica comb. nov. (Leguminosae),Acer watarianum Takahashi et Suzuki (Aceraceae),Meliosma mio-oldhami sp. nov. (Sabiaceae),Reevesia miocenica Watari (Sterculiaceae), andFraxinus notoensis sp. nov. (Oleaceae). The fossil wood floras at the two localities are compared to the Daijima Flora, and warm-and/or cool-temperate mesic forests are suggested to occur in the Early Miocene of Monzen.     

Taxonomic review of the genus Xenolecanium Takahashi and description of the new genus Takahashilecanium Kondo (Hemiptera: Coccidae; Coccinae, Paralecaniini)

The genus Xenolecanium Takahashi is reviewed and transferred from the subfamily Myzolecaniinae to the Coccinae (tribe Paralecaniini). The type species Xenolecanium mangiferae Takahashi is redescribed, and Xenolecanium takahashii Kondo sp. nov. from Indonesia is described based on the adult female and first instar nymph. A taxonomic key is provided to separate adult females of the two species of Xenolecanium. Xenolecanium rotundum Takahashi is transferred to become the type species of a new monotypic genus, Takahashilecanium Kondo, which is also placed in the Paralecaniini. The morphological justification for placing Xenolecanium and Takahashilecanium in the Paralecaniini is discussed, and we provide a taxonomic key for separating both genera from all other members of the Paralecaniini.     

Notch signal is sufficient to direct an endothelial conversion from non-endothelial somitic cells conveyed to the aortic region by CXCR4

During the early formation of the dorsal aorta, the first-forming embryonic vessel in amniotes, a subset of somitic cells selected as presumptive angioblasts, migrates toward the dorsal aorta, where they eventually differentiate into endothelial cells. We have recently shown that these processes are controlled by Notch signals (Sato, Y., Watanabe, T., Saito, D., Takahashi, T., Yoshida, S., Kohyama, J., Ohata, E., Okano, H., and Takahashi, Y., 2008. Notch mediates the segmental specification of angioblasts in somites and their directed migration toward the dorsal aorta in avian embryos. Dev. Cell 14, 890-901.). Here, we studied a possible link between Notch and chemokine signals, SDF1/CXCR4, the latter found to be dominantly expressed in developing aorta/somites. Although CXCR4 overexpression caused a directed migration of somitic cells to the aortic region in a manner similar to Notch, no positive epistatic relationships between Notch and SDF1/CXCR4 were detected. After reaching the aortic region, the CXCR4-electroporated cells exhibited no endothelial character. Importantly, however, once provided with Notch activity, they could successfully be incorporated into developing vessels as endothelial cells. These findings were obtained combining the tetracycline-inducible gene expression method with the transposon-mediated stable gene transfer technique. We conclude that Notch activation is sufficient to direct naïve mesenchymal cells to differentiate into endothelial cells once the cells are conveyed to the aortic region.     

Negative Phototaxis from Blue Light and the Role of Third Rhodopsinlike Pigment in Halobacterium Cutirubrum

Wild-type cells of Halobacterium cutirubrum show phototaxis. In negative phototaxis the cells are repelled by blue-near ultraviolet light, and in positive phototaxis the cells are attracted to green-red light. The extent of the responses are measured by monitoring the changes in the reversal frequency of the swimming direction of cells using a computer-linked automated method as described previously (Takahashi, T., and Y. Kobatake, 1982, Cell. Struct. Funct., 7:183-192). When the intensity of the background light (illumination for the observation) was dramatically reduced, the sensitivity of the cells to the repellent light decreased markedly. This result has been previously explained by Bogomolni and Spudich (1982, Proc. Natl. Acad. Sci. USA, 79:6250-6254), who proposed that the photoreceptor for negative phototaxis is the long-lifetime intermediate in the photocycle of slow-rhodospin. The behavioral response in the negative phototaxis is dependent upon the intensity of the actinic light and the background light. This agrees quantitatively with our model based on the aforementioned hypothesis.     

Sequential production of two biopolymers-levan and poly-ε-lysine by microbial fermentation

Sequential fermentation for the production of two invaluable biopolymers, levan and poly-ε-lysine (ε-PL), has been successfully developed. It involves fermentation of Bacillus subtilis (natto) Takahashi in sucrose medium to produce levan, separation of levan product from small remaining sugar molecules by ultrafiltration and fermentation of the remnant from levan production by Streptomyces albulus to produce ε-PL. In the process, 50-60 g/L of levan was produced (100% recovery after precipitation by ethanol). The remnant from levan production with glucose adjusted to 30 g/L and with combined use of yeast extract (10 g/L), (NH₄)₂SO₄ (2 g/L) and basal salts was proven to be suitable for ε-PL production. 4.37 g/L of ε-PL accumulation (85% recovery after purification) was reached in 72 h using two-stage fermentation with control of pH. The process of using remnant (waste) from levan fermentation for the second biopolymer (ε-PL) production is unprecedented and the products obtained are environmental-friendly.     

Role of genes O and P in the replication of bacteriophage lambda DNA.

DNA replication in coliphage λ occurs in two stages. The first round of replication generates mainly circular progeny DNA by a double-branched θ-type replicative form (Ogawa et al., 1968; Schnös &; Inman, 1970). In the late stage of λ DNA replication, however, σ-type rolling-circle replicative form DNA molecules, which produce multigenomic linear concatemers, are primarily found (Takahashi, 1974).At both early and later times, a temperature shift of λ Ots or Pts infected cells from 32 °C (permissive) to 43 °C (non-permissive temperature) caused a rapid reduction of the rate of radioactive precursor incorporation into λ DNA, showing that the gene O and P products are essential for the continuation of λ DNA synthesis. Observations on the molecular fine structure of the replicating fork after a temperature shift revealed characteristic long “single-strand connections” and single-strand “whiskers” at the branch point. These observations suggest that λ gene O and P products are directly involved in the propagation of daughter strands.     

Toward a more International and Reputable Journal

Editors in 2004 In 2004 I, Hiroo Fukuda (University of Tokyo), was appointedto be the Editor-in-Chief of Plant and Cell Physiology (PCP).As my first task I have added four overseas and four domesticEditors: John Harada (University of California, Davis), FumihikoKatagiri (University of Minnesota, from July), Jiayang Li (ChineseAcademy of Science), Eberhard Schäfer (Freiburg University,from July), Ikuko Hara-Nishimura (Kyoto University), FumihikoSato (Kyoto University), Ichiro Terashima (Osaka University)and Hideyuki Takahashi (Tohoku University, from July). I would like to take     

Functional response and reproductive attributes of the aphidophagous ladybird beetle,Harmonia dimidiata (Fabricius) in oak trees of sericultural importance

Harmonia dimidiata (Fabricius) (Coleoptera: Coccinellidae) is the dominant predator of the aphid species Cervaphis quercus Takahashi. This aphid is a serious pest of oak trees in several parts of north-east India. Young leaves of oak trees are used in sericulture by rural people and by industry in several parts of north-east India. The effect of different aphid densities on food consumption and fecundity of H. dimidiata was studied in the laboratory. Female beetles were maintained from the time of eclosion till death at a fixed density of 25, 50, 75,100 or 125 aphids. Both the functional response and the reproductive numerical response showed the upper asymptote at 100 adult aphids/female. At this density, females matured earlier and produced more eggs over a longer reproductive period. At lower prey densities, females matured late and they either did not produce eggs or produced fewer eggs. At the higher prey densities, females did not produce more eggs than the asymptote. Results suggested that H. dimidiata are an effective predator of C. quercus aphids on oak trees and could be exploited as a biological control agent in the rising phase of aphid population growth.     

桑粉虱形态研究

研究描述了容易与杨梅粉虱混淆的重要害虫桑粉虱Pealius mori(Takahashi)成虫、卵、1～4龄若虫及蛹的形状、分类特征,包括成虫的体长、体色、触角、单眼、复眼、口器、翅、足及雌雄外生殖器;卵的形状、大小、卵色及卵柄;1～4龄若虫及蛹的形状、大小、体色、体周的刚毛、触角、口器、足、管状孔、盖瓣、舌状器及腹沟等。并比较桑粉虱与杨梅粉虱的主要分类特征。     

GNOM-Mediated Vesicular Trafficking Plays an Essential Role in Hydrotropism of Arabidopsis Roots

Roots respond not only to gravity but also to moisture gradient by displaying gravitropism and hydrotropism, respectively, to control their growth orientation, which helps plants obtain water and become established in the terrestrial environment. As gravitropism often interferes with hydrotropism, however, the mechanisms of how roots display hydrotropism and differentiate it from gravitropism are not understood. We previously reported MIZU-KUSSEI1 (MIZ1) as a gene required for hydrotropism but not for gravitropism, although the function of its protein was not known. Here, we found that a mutation of GNOM encoding guanine-nucleotide exchange factor for ADP-ribosylation factor-type G proteins was responsible for the ahydrotropism of Arabidopsis (Arabidopsis thaliana), miz2. Unlike other gnom alleles, miz2 showed no apparent morphological defects or reduced gravitropism. Instead, brefeldin A (BFA) treatment inhibited both hydrotropism and gravitropism in Arabidopsis roots. In addition, a BFA-resistant GNOM variant, GN^M696L, showed normal hydrotropic response in the presence of BFA. Furthermore, a weak gnom allele, gnom^B/E, showed defect in hydrotropic response. These results indicate that GNOM-mediated vesicular trafficking plays an essential role in hydrotropism of seedling roots.Stationary growth is a distinct feature of plants and distinguishes them from other organisms. Plants have evolved a variety of mechanisms for responding to environmental cues, which enables them to survive in the presence of limited resources or environmental stresses. One of the most important growth adaptations plants have acquired is tropism, growth response that involves bending or curving of plant organs toward or away from a stimulus. For example, roots display tropisms in response to environmental cues such as gravity, light, touch, and moisture (Darwin and Darwin, 1880; Takahashi, 1997; Correll and Kiss, 2002; Monshausen et al., 2008). Gravitropism has been the subject of intense study, while other tropic responses of roots have been less well characterized. There is some evidence of hydrotropism in roots, but this response has proven difficult to differentiate from gravitropism, as the latter always interferes with hydrotropism (Jaffe et al., 1985; Takahashi, 1994; Takahashi, 1997). The demonstration of true hydrotropism in roots has facilitated the identification of some of the physiological aspects of hydrotropism and its existence in a wide range of plant species. However, the underlying mechanisms that regulate hydrotropism remain unknown. The limited supply of water and precipitation in many parts of the world greatly affects agriculture and ecosystems. Elucidating the molecular mechanism of hydrotropism in roots is therefore important not only for understanding how terrestrial plants adapt to changes in moisture, but also for improving crop yields and biomass production.The isolation and analysis of hydrotropism-deficient mutants using the model plant species Arabidopsis (Arabidopsis thaliana) represents a potent tool for dissecting the molecular mechanism of hydrotropism. Previously, we isolated an ahydrotropic mutant of Arabidopsis, mizu-kussei1 (miz1), and showed that MIZ1 encodes a protein of unknown function (Kobayashi et al., 2007). In light of both the physiological features of hydrotropism, as well as what we have learned from genetic studies of other tropisms, it is unlikely that miz1 alone governs the hydrotropic response. In support of this, we have identified a second ahydrotropic mutant, miz2, a unique allele of gnom that confers ahydrotropic but not agravitropic growth, which implies distinct roles of vesicular trafficking between hydrotropism and gravitropism in roots.     

The aphid Ceratovacuna nekoashi (Hemiptera: Aphididae: Hormaphidinae) and its allied species in Korea,Japan and Taiwan

The aphid Ceratovacuna nekoashi and its allied species have been a taxonomically difficult group. They form peculiar “cat's‐paw” galls (called “Nekoashi” in Japanese) on Styrax trees and also use Microstegium grasses as their secondary hosts. Through sampling aphids from both Styrax galls and Microstegium grasses in South Korea, Japan and Taiwan, and sequencing their DNA, we made it clear that four distinct species occur in these regions: C. nekoashi (Sasaki), C. oplismeni (Takahashi), C. orientalis (Takahashi) and C. subtropicana sp. nov. In Korea, C. nekoashi forms galls on both S. japonicus and S. obassia, whereas in Japan the species forms galls on the former but not on the latter; our molecular analyses unequivocally indicated the occurrence of a single species in South Korea and mainland Japan. Aphids of the four species on the secondary host were morphologically discriminated from one another. The identity of the primary‐ and secondary‐host generations was also clarified for each species. All four species were found to produce second‐instar sterile soldiers in their Styrax galls, and first‐instar soldiers were found in colonies of C. subtropicana on the secondary host.