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181.
The green lacewing, Chrysoperla carnea (Stephens), is an important natural enemy of various crop pests, especially aphids. In the Japanese fauna, there are two types of larval forms, A and B, characterized by different head capsule markings. The Type A form is distributed throughout Japan, but the Type B form has a more limited distribution. Adults use abdominal vibration as a communication signal (courtship song) during mating. We analyzed oscillograms of these songs among several Japanese populations of C. carnea. The courtship songs of types A and B are distinctly different from one another. We then performed crossing tests between the two types. Copulation between same-type pairings was much more likely than between different-type pairings. We also analyzed courtship songs of European C. carnea sensu stricti, introduced to Japan as a natural enemy of crop pests. The song of these introduced green lacewings appeared to differ from either type of Japanese C. carnea. The two types of C. carnea are likely to be different species, and also distinct from C. carnea sensu stricti of Europe. 相似文献
182.
Renault-Mihara F Okada S Shibata S Nakamura M Toyama Y Okano H 《The international journal of biochemistry & cell biology》2008,40(9):1649-1653
Spinal cord injury (SCI), despite considerable progress in palliative care, has currently no satisfying therapeutic leading to functional recovery. Inability of central nervous system severed axons to regenerate after injury is considered to originate from both limited intrinsic capabilities of neurons and inhibitory effect of the local environment. Precisely, the so-called "glial scar" formed by reactive astrocytes in response to injury exerts a well-known axon-outgrowth inhibitory effect. However, recent studies revealed that role of reactive astrocytes after SCI is more complex. During the first weeks after injury, reactive astrocytes indeed protect the tissue and contribute to a spontaneous relative functional recovery. Compaction of the lesion center and seclusion of inflammatory cells by migrating reactive astrocytes seem to underlie this beneficial effect. Stimulation of reactive astrocytes migration in the sub-acute phase of SCI might thus represent a new approach to improve the functional outcome of patients. 相似文献
183.
Mrp antiporters catalyze secondary Na(+)(Li(+))/H(+) antiport and/or K(+)/H(+) antiport that is physiologically important in diverse bacteria. An additional capacity for anion flux has been observed for a few systems. Mrp is unique among antiporters in that it requires all six or seven hydrophobic gene products (MrpA to MrpG) of the mrp operon for full antiporter activity, but MrpE has been reported to be dispensable. Here, the membrane complexes formed by Mrp proteins were examined using a cloned mrp operon from alkaliphilic Bacillus pseudofirmus OF4. The operon was engineered so that the seven Mrp proteins could be detected in single samples. Membrane extracts of an antiporter-deficient Escherichia coli strain expressing this construct were analyzed by blue native-sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mrp complexes of two sizes were identified containing all seven Mrp proteins. Studies of the single nonpolar mrp gene deletions in the construct showed that a subcomplex of MrpA, MrpB, MrpC, and MrpD was formed in the absence of MrpE, MrpF, or MrpG. By contrast, MrpE, MrpF, and MrpG were not observed in membranes lacking MrpA, MrpB, MrpC, or MrpD. Although MrpA and MrpD have been hypothesized to be the antiporter proteins, the MrpA-to-D complex was inactive. Every Mrp protein was required for an activity level near that of the wild-type Na(+)/H(+) antiporter, but a very low activity level was observed in the absence of MrpE. The introduction of an MrpE(P114G) mutation into the full Mrp complex led to antiport activity with a greatly increased apparent K(m) value for Na(+). The results suggested that interactions among the proteins of heterooligomeric Mrp complexes strongly impact antiporter properties. 相似文献
184.
Sang-Gyu Seo Seung-Won Kang Ie-Sung Shim Wook Kim Shinsuke Fujihara 《Plant Growth Regulation》2009,57(3):251-258
To understand the factors that induce floral senescence in Hibiscus syriacus L., we have investigated the effects of various chemical agents on flower senescence at two different flowering stages, before
and after full bloom, as well as the relationship between flower longevity and endogenous ethylene production before full
bloom. Treatments with ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), and ethephon enhanced floral senescence, while
aminoethoxyvinylglycine (AVG) promoted flower longevity regardless of treatment timing. Although ethanol slightly extended
flower longevity, abscisic acid (ABA), nitric oxide, boric acid and sucrose, which have been reported to affect flower longevity
or senescence, had no effect on H. syriacus floral senescence. The polyamine spermine (SPM), methylglyoxal-bis(guanylhydrazone) (MGBG), an inhibitor of SPM biosynthesis,
and cycloheximide (CHI) accelerated flower senescence when applied before full bloom, but had no effect when applied after
full bloom. SPM, MGBG and CHI treatments resulted in enhanced ethylene production during flower opening, and the promotion
of flower senescence is mediated by ethylene production prior to full bloom. Furthermore, endogenous ethylene, spontaneously
produced before blooming, was closely associated with floral senescence. These results suggest that ethylene production during
flower opening plays a key role in determining the timing of Hibiscus flower senescence. 相似文献
185.
Schouler C Taki A Chouikha I Moulin-Schouleur M Gilot P 《Journal of bacteriology》2009,191(1):388-393
Prebiotics such as fructooligosaccharides (FOS) are increasingly being used in some countries for improving human and animal health and as an alternative to antibiotic growth promoters in animals, with various degrees of success. It has been observed that FOS stimulate the proliferation of probiotic bacteria and, at the same time, decrease the population of bacteria associated with disease. This observation assumes that pathogenic bacteria do not metabolize FOS and, therefore, lose their competitive advantage over beneficial bacteria. Here we present evidence that some pathogenic Escherichia coli strains can metabolize FOS and show that this property helps the bacterium colonize the intestine. These findings highlight the potential risk that a high level of prebiotic usage could lead to the emergence of well-adapted pathogenic strains that metabolize prebiotic substances. 相似文献
186.
Masatoshi Nakamoto Shinsuke Muramatsu Shoko Yoshida Masaru Matsuda Yoshitaka Nagahama Naoki Shibata 《Genesis (New York, N.Y. : 2000)》2009,47(5):289-299
Oryzias luzonensis is closely related to the medaka, O. latipes. The sex of both species is determined by an XX‐XY system. However, the testis determining gene (DMY/Dmrt1bY) found in O. latipes does not exist in O. luzonensis. Instead, a different gene is thought to act as a testis determining gene. In this study, we focused the gonadal sex differentiation process in O. luzonensis under different testis determining gene. First, we observed the gonadal development of O. luzonensis histologically. We then analyzed the expression of Sox9a2/Sox9b, Dmrt1, and Foxl2 during early development. Our results suggest that the sexual differentiation of germ cells in O. luzonensis is initiated later than in O. latipes. However, the timing of the sexual differentiation of the supporting cell linage is similar between the species. genesis 47:289–299, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
187.
188.
Yuka Ogata Shinsuke Morioka Kosuke Sano Bounsong Vongvichith Hiroki Eda Hisashi Kurokura Thongkhoun Khonglaliane 《Ichthyological Research》2010,57(4):389-397
The morphological development, including the pigmentation, body proportions, fins, and survival rate for 30 days after hatching, of laboratory-reared larval and juvenile Hypsibarbus malcolmi is described. Body lengths (BL) of larvae and juveniles were 2.0 ± 0.2 (mean ± SD) mm at 1 h after hatching (day 0) and 9.2 ± 0.6 mm on day 16, reaching 12.1 ± 0.9 mm on day 30. Yolk volume decreased linearly, with the yolk being completely absorbed by day 3 in all preflexion larvae (all specimens >3.2 mm BL). Feeding was observed on day 2 in fish which had rapidly undergone complete yolk absorption following mouth and anus opening on day 1, and on day 3 in all remaining fish. Myomere numbers were 20–21 + 11–12 = 31–33, although they were not clearly visible in juveniles. Melanophores were few on the body during days 0–2, but increased with growth and covered the entire upper dorsal body surface during the juvenile stage. Body proportions tended to become constant in juveniles. Notochord flexion began in larvae >5.2 mm BL on day 8, and was completed in larvae >8.4 mm BL on day 14. Specimens with full fin ray complements were initially observed on day 22 (10.4 mm BL in juveniles). All specimens >11.5 mm BL had attained the juvenile stage. A high survival rate of 92.7% was estimated on day 30. 相似文献
189.
Shinozuka T Shimada K Matsui S Yamane T Ama M Fukuda T Taki M Takeda Y Otsuka E Yamato M Mochizuki S Ohhata K Naito S 《Bioorganic & medicinal chemistry》2006,14(20):6789-6806
A novel series of cathepsin K inhibitors derived from Novartis compound I is described. Optimization of the P1, P3, and P1' units led to the identification of 4-aminophenoxyacetic acid 24b with an IC(50) value of 4.8 nM, which possessed an excellent selectivity over other human cathepsins and good pharmacokinetic (PK) properties. Oral administration of compound 24b to ovariectomized (OVX) rats showed a trend toward an improvement of bone mineral density (BMD) in the femur bone. 相似文献
190.