Ecdysteroids inLimulus larvae

Summary Free ecdysteroids were extracted from intermolt and premolt larvae ofLimulus polyphemus in the first posthatch stage, purified by TLC and HRLC, and assayed by RIA and theLimulus bioassay 20-hydroxyecdysone appears to be a principal ecdysteroid and occurs at least 3 times higher a concentration in premolt vs intermolt animals.Supported by NSF grant GB-40620.Acknowledgments. We are indebted to Prof. G. R. Wyatt for the antibody, Prof. K. Nakanishi for use of his laboratory for HRLC separations, and to Dr David King for the³H-ecdysone and for performing radio-TLC analyses.     

Expression of the mutant gene for L-gulono-gamma-lactone oxidase in scurvy-prone rats

A mutant strain of Wistar rats with L-gulono-gamma-lactone oxidase deficiency has recently been established. To investigate this deficiency by DNA and RNA blot hybridization analyses, a fragment of a previously cloned cDNA encoding rat L-gulono-gamma-lactone oxidase was used as a probe. When genomic DNA of the mutant rat was digested with several restriction enzymes, the probe hybridized to fragments of the same sizes as those produced from DNA of normal rats. Poly(A)+RNA from the liver of the mutant rat was found to contain an L-gulono-gamma-lactone oxidase-specific mRNA of a normal size at a comparable level to that of normal rats. An in vitro translation experiment revealed that the mRNA programmed the synthesis of an enzyme protein which had the same molecular weight as that of the translational product of the normal mRNA, although the amount synthesized was markedly reduced as compared with that synthesized with the normal mRNA. In accordance with this observation, a very low but definite degree of L-gulono-gamma-lactone oxidase activity was detected in the microsomes of the mutant rat by a newly developed, highly sensitive method.     

Calcitonin-like peptide in the shrimpPalaemon serratus (Crustacea,Decapoda) during the intermolt cycle

Summary A molecule immunologically related to salmon calcitonin has been detected in the hemolymph of the shrimpPalaemon serratus. Its concentration varies inversely with the calcium level during the molt cycle; a maximum (14 ng/ml) is found in the post-molt stage and a minimum (0.5 ng/ml) during the premolt stage.     

盐酸戊乙奎醚对大鼠感染性脑水肿AQP4表达的影响

目的：研究盐酸戊乙奎醚对感染性脑水肿保护作用的机制。方法：采用左颈内动脉注射脂多糖复制大鼠感染性脑水肿模型,将84只雄性SD大鼠随机分为对照组（C组）、水肿组（I组）、盐酸戊乙奎醚治疗组（P组）。检测6h、12h、24h、48h时各组大鼠脑组织含水量、病理形态;脑组织SOD活性、MDA含量;免疫组化法及RT—PCR法检测AQP4蛋白分布与AQP4mRNA含量。结果：（1）与C组相比,I组、P组脑含水量、MDA含量均升高,同时SOD活性、AQP4蛋白、AQP4mRNA表达均减少（P〈0．01）。与对应时间点P组相比,I组脑含水量、MDA含量均升高,同时SOD活性、AQP4蛋白、AQP4mRNA表达均减少,于24h达高峰,48h仍在较高水平（P〈0．01）。（2）脑组织光镜检查：I组大鼠脑组织损伤严重,P组损伤明显减轻。结论：盐酸戊乙奎醚能在一定程度上可减轻感染所致的脑组织损伤,上调AQP4表达,对脑水肿有一定治疗作用,其机制可能与抗氧化作用有关。     

Expression of the mutant gene for L-gulono-γ-lactone oxidase in scurvy-prone rats

A mutant strain of Wistar rats with L-gulono--lactone oxidase deficiency has recently been established. To investigate this deficiency by DNA and RNA blot hybridization analyses, a fragment of a previously cloned cDNA encoding rat L-gulono--lactone oxidase was used as a probe. When genomic DNA of the mutant rat was digested with several restriction enzymes, the probe hybridized to fragments of the same sizes as those produced from DNA of normal rats. Poly(A)⁺RNA from the liver of the mutant rat was found to contain an L-gulono--lactone oxidase-specific mRNA of a normal size at a comparable level to that of normal rats. An in vitro translation experiment revealed that the mRNA programmed the synthesis of an enzyme protein which had the same molecular weight as that of the translational product of the normal mRNA, although the amount synthesized was markedly reduced as compared with that synthesized with the normal mRNA. In accordance with this observation, a very low but definite degree of L-gulono--lactone oxidase activity was detected in the microsomes of the mutant rat by a newly developed, highly sensitive method.Acknowledgments. The authors thank Dr Susumu Makino, Shionogi Research Laboratories, Shionogi & Co., Ltd, Japan, for his kind donation of normal (ODS- +/+) and ODS (ODS-od/od) rats. This work was supported in part by Grant-in-Aid (59570103) for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

Etude de l'influence d'une microsporidiose sur les électrophorégrammes (protéinogramme et zymogramme) des protéines de l'hémolymphe deCarcinus mediterraneus (Crustacé, Brachyoure)

Summary The use of the method of concentration gradient of polyacrylamide gel, electrophoresis has permitted to reveal a difference in zymograms when studying the hemolymph of healthy crabs and that of crabs parasitized by the muscular microsporidaThelohania, maenadis., The zymograms of the parasitized crabs present an increase in chymotrypsin activity and variations in the zones of esterase activity.

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Contribution n^o 1 du Centre de Parasitologie et de Pathologie comparées de l'Université des Sciences et Techniques du Languedoc, F-34060 Montpellier Cédex.     

Proopiomelanocortin expression in the skin during induced hair growth in mice.

We demonstrate for the first time a hair cycle-dependent gene and protein expression of proopiomelanocortin in mouse skin in vivo. Northern blot detected POMC mRNA with an apparent size of 0.9 kb in anagen but not telogen skin. Western blot emphasized a specific protein of 30-33 kDa recognized by anti beta-endorphin in late but not early anagen or telogen skin. By immunocytochemistry, beta-endorphin antigen was localized in the sebaceous gland in a hair cycle dependent manner.     

Hybridization histochemistry

Summary The location of gene expression by hybridization histochemistry is being applied in many areas of research and diagnosis. The aim of this technique is to detect specific mRNA in cells and tissues by hybridization with a complementary DNA or RNA probe. Requirements for optimal specificity, sensitivity, resolution and speed of detection may not all be encompassed in one simple technique suitable for all applications, thus appropriate procedures should be selected for specific objectives. With reference to published procedures and our own extensive experience, we have evaluated fixatives, probes, labels and other aspects of the technique critical to the preservation and hybridization in situ of mRNA and detection and quantition of hybrids.     

Hybridization histochemistry

The location of gene expression by hybridization histochemistry is being applied in many areas of research and diagnosis. The aim of this technique is to detect specific mRNA in cells and tissues by hybridization with a complementary DNA or RNA probe. Requirements for optimal specificity, sensitivity, resolution and speed of detection may not all be encompassed in one simple technique suitable for all applications, thus appropriate procedures should be selected for specific objectives. With reference to published procedures and our own extensive experience, we have evaluated fixatives, probes, labels and other aspects of the technique critical to the preservation and hybridization in situ of mRNA and detection and quantitation of hybrids.     

Increase in acid phosphatase activity during fertilization of a teleost egg

Summary Acid phosphatase activity was localized at the periphery of the yolk globules in the egg of the teleost,Catostomus commersoni. In addition, a 3-fold increase in acid phosphatase activity was associated with fertilization and pronucleus formation.I thank Dr C. W. Huver for use of facilities.     

Expression and immunolocalisation of odorant-binding and chemosensory proteins in locusts

We have identified, cloned and expressed a new chemosensory protein (CSP) in the desert locust Schistocerca gregaria belonging to a third sub-class of these polypeptides. Polyclonal antibodies stained a band of 14 kDa, as expected, in the extracts of antennae and palps of the adults, but not in the 4th and 5th instars. In the related species Locusta migratoria, instead, the same antibodies cross-reacted only with a band of apparent molecular mass of 35 kDa in the extract of 1st–5th instars, but not in the adults. The recombinant protein binds the fluorescent probe N-phenyl-1-naphthylamine, but none of the compounds so far reported as pheromones for S. gregaria. The expression of the odorant-binding protein (OBP) and of CSPs of sub-classes I and II was also monitored in antennae, tarsi, palpi, wings and other organs of solitary and gregarious locusts in their nymphal and adult stages. OBP was found to be antenna specific, where it is expressed at least from the 3rd instar in both solitary and gregarious locusts. CSPs, instead, appear to be more ubiquitous, with different expression patterns, according to the sub-class. Immunocytochemistry experiments revealed that OBP is present in the sensillum lymph of sensilla trichodea and basiconica, while CSP-I and CSP-III were found in the outer sensillum lymph of sensilla chaetica and in the sub-cuticular space between epidermis and cuticle of the antenna. Sensilla chaetica on other parts of the body showed the same expression of CSP-I as those on the antenna.Received 11 Janury 2005; received after revision 21 February 2005; accepted 18 March 2005X. Jin and A. Brandazza contributed equally to this work.     

Ciliary structures in the branchial unicellular glands of the grass shrimp,Palaemonetes pugio

Summary A unicellular exocrine gland possessing an epicuticular ductule occurs in grass shrimp gills. This gland displays ultrastructural changes in relation to the molt cycle. These changes include an increase in the quantity of secretory granules during late premolt, and the development of ciliary axonemes in relation to ductule formation.This investigation was supported in part by grant CR-807417 from the U.S. Environmental Protection Agency.     

Proopiomelanocortin expression in the skin during induced hair growth in mice

We demonstrate for the first time a hair cycle-dependent gene and protein expression of proopiomelanocortin in mouse skin in vivo. Northern blot detected POMC mRNA with an apparent size of 0.9 kb in anagen but not telogen skin. Western blot emphasized a specific protein of 30–33 kDa recognized by anti -endorphin in late but not early anagen or telogen skin. By immunocytochemistry, -endorphin antigen was localized in the sebaceous gland in a hair cycle dependent manner.     

Functions and transport of silicon in plants

Silicon exerts beneficial effects on plant growth and production by alleviating both biotic and abiotic stresses including diseases, pests, lodging, drought, and nutrient imbalance. Recently, two genes (Lsi1 and Lsi2) encoding Si transporters have been identified from rice. Lsi1 (low silicon 1) belongs to a Nod26-like major intrinsic protein subfamily in aquaporin, while Lsi2 encodes a putative anion transporter. Lsi1 is localized on the distal side of both exodermis and endodermis in rice roots, while Lsi2 is localized on the proximal side of the same cells. Lsi1 shows influx transport activity for Si, while Lsi2 shows efflux transport activity. Therefore, Lsi1 is responsible for transport of Si from the external solution to the root cells, whereas Lsi2 is an efflux transporter responsible for the transport of Si from the root cells to the apoplast. Coupling of Lsi1 with Lsi2 is required for efficient uptake of Si in rice. Received 21 December 2007; received after revision 29 April 2008; accepted 15 May 2008