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1.
All olfactory receptors identified in teleost fish are expressed in a single sensory surface, whereas mammalian olfactory receptor gene families segregate into different olfactory organs, chief among them the main olfactory epithelium expressing ORs and TAARs, and the vomeronasal organ expressing V1Rs and V2Rs. A transitional stage is embodied by amphibians, with their vomeronasal organ expressing more ‘modern’, later diverging V2Rs, whereas more ‘ancient’, earlier diverging V2Rs are expressed in the main olfactory epithelium. During metamorphosis, the main olfactory epithelium of Xenopus tadpoles transforms into an air-filled cavity (principal cavity, air nose), whereas a newly formed cavity (middle cavity) takes over the function of a water nose. We report here that larval expression of ancient V2Rs is gradually lost from the main olfactory epithelium as it transforms into the air nose. Concomitantly, ancient v2r gene expression begins to appear in the basal layers of the newly forming water nose. We observe the same transition for responses to amino acid odorants, consistent with the hypothesis that amino acid responses may be mediated by V2R receptors.  相似文献   

2.
Summary Pressmud, a sugar factory waste, was fermented with methanogenic bacteria in an anaerobic fermenter for 40 days at 31±2°C. The pressmud residue obtained after fermentation was used as a source for the extraction of phytosterols. The anaerobic digestion degraded the organic matter and resulted in enrichment of phytosterols from 0.33% in the pressmud to 3.05% in the residue. Refluxing of 100 g of residue with benzene, petroleum ether, and ethanolic KOH (1051) yielded 8 g of soft cake, which on further fractionation with methylcyanide and isopropanol gave three fractions: 1) a crude mixture of phytosterols, 2) resin, and 3) undigested organic matter. The crude mixture of phytosterols after purification on neutral alumina followed by GLC analysis resulted in the separation of 68.7% of -sitosterol, 18.4% of stigmasterol and 12.9% of campesterol and brassicasterol together. Phytosterols were extracted more easily from fermented than from unfermented samples, because of biodegration of lipophilic compounds by the methanogenic bacteria.Acknowledgments. S.K.S. and J.C.S. are thankful to the authorities of the U.G.C., New Delhi, for the award of Teacher-fellowships. R.C.S., R.A.K.S. and D.K.M. are thankful to the authorities of the C.S.I.R., New Delhi, for providing R.A., S.R.F., and J.R.F., respectively. Reprint request to S.N.M.  相似文献   

3.
Summary Under the action of the appropriate synthase from ripe tomatoes a 11 mixture of (3S, 4R)-[3,4-2H2] and (3R, 4S)-[3,4-2H2]-(2S)-adenosylmethionine is transformed into a 11 mixture of the two meso forms of [2H2]-1-aminocyclopropanecarboxylic acid, a result which proves the operation of an inversion mechanism and which is consistent with direct nucleophilic displacement of the leaving group in the substrate.  相似文献   

4.
Summary In the human leukemia K-562(S6) cell line (a) the accumulation ofa-globin chains is low or absent, (b) -globin gene expression is correlated with expression of -chains and (c) the genes responsible for the terminal cell division are not operated within 8–12 cell cycles, while K-562 (S6) cells are fully induced to erythroid differentiation.This work was supported by grants from the Italian National Research Council (C.N.R.) G. R. is a recipient of a fellowship from the National Committee for Nuclear Energy, Rome. Address for reprint requests: R. G., Centro di Studi Biochimici, Via L. Borsari 46, I-44100 Ferrara.  相似文献   

5.
Summary Biological activity of enantiomerically pure juvenile hormones was assayed by topical application on allatectomizedBombyx fourth instar larvae. JHs tested were (10R)-JH I [methyl (2E,6E,10R,11S)-10,11-epoxy-3,11-dimethyl-7-ethyl-2,6-tridecadienoate], (10S)-JH I [methyl (2E, 6E, 10S, 11R)-10,11-epoxy-3,11-dimethyl-7-ethyl-2,6-tridecadienoate], (10R)-JH III [methyl (2E,6E,10R)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate] and (10S)-JH III [methyl (2E,6E,10S)-10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate]. Among these compounds, natural (10R)-JH I was most active and the dose needed to induce 50% larval molting was 0.04 g/larva; it was approximately 12,000 times more active than unnatural (10S)-JH I. Though natural (10R)-JH III showed slight biological activity, it was only one three-thousandth of that of (10R)-JH I. Unnatural (10S)-JH III exhibited no biological activity at the levels assayed.  相似文献   

6.
Summary A one-step synthesis of hexahydrocannabinoid analogs (HHC) is described making use of the condensation of phenolic ketones and aldehydes with citronellal in the presence of pyridine.Grateful thanks are accorded to Drs L. Chopard and S. Selvavinayakam for spectral measurements and Dr I. Fleming for useful discussion.R. Mechoulam and Y. Gaoni, Recent advances in the chemistry of Hashish, in: Progress in the Chemistry of Organic natural products, vol. 25, p. 175. Ed. L. Zechmeister. Springer Verlag, Wien 1967; R. Mechoulam, Marijuana Chemistry and Pharmacology, metabolism and clinical effects. Academic Press, New York 1973; R. Mechoulam, N. K. McCallum and S. Burstein, Chem. Rev.76, 75 (1976).  相似文献   

7.
Summary The epidermis, which lines the uropygial invaginations and which then forms the primary and secondary buds, is separated from the mesenchyma by an uninterrupted basal lamina. Between the end of the internal morphogenesis and the beginning of the secretory activity, direct intertissular contacts are established through the gaps in the basal lamina. They appear to be related to the induction of glandular differentiation.Ce travail a été réalisé avec l'aide financière de la D. G. R. S. T. (action concertée D. G. R. S. T. Biologie de la Reproduction et du Développement, contrat No. 75-7-0803).  相似文献   

8.
Summary A simple method to prepare chromosome spreads of hydra is described. Chromosome counts for a non-symbiotic brown hydra,Hydra vulgaris attenuata, and the Swiss strain of a symbiotic green hydra indicated a diploid number of about 2n=30 in each case. It is suggested that chromosome number may be used to define hydra species more precisely.This work was done while A. R. and M. R. were on leave in Oxford. We thank Prof. D. C. Smith F. R. S. for providing laboratory facilities. We wish to thank Prof. Smith and Dr A. E. Douglas for reading earlier drafts of this paper.  相似文献   

9.
Summary The activity of the pure 10R (=natural) and 10S enantiomers of juvenile hormone III (JH III) was determined in 3 different bioassays, and the relative binding affinity of the 2 enantiomers to the haemolymph JH-binding protein of the cockroachNauphoeta cinerea was measured. In theGalleria wax test, a local morphogenetic assay, the 10R enantiomer was 5240 times more active than, the 10S enantiomer, 1Galleria unit corresponding to 0.42 pg of 10R-JH III as compared to 2.2 ng for 10S-JH III. In a systemic morphogenetic assay with the cockroachNauphoeta cinerea 380 times less 10R enantiomer was necessary in order to induce detectable juvenilisation (58 ng 10R and 22 g 10S) and in a systemic gonadotropic assay withNauphoeta cinerea 255 times less 10R was needed to induce vitellogenin synthesis in 50% of the insects (6.7 ng 10R and 1710 ng 10S). In the JH-binding protein assay 10R-JH III had an affinity for the JH-binding protein (lipophorin) which was approximately 46 times higher than that of 10S-JH III.  相似文献   

10.
Summary Structures of iselin and iliensin have been revised. The structure (Ib) is secured for iselin by a direct comparison (m.p., UV, IR, PMR) with archangelin. The synthesis of iliensin (IIb) has been effected through the condensation of xanthotoxol (II, R=OH) and -cyclolavandulyl bromide (III). The synthetic product has been shown to be identical with natural iliensin.We thank Dr S.Z. Qasim and Dr M.S. Chadha for the spectral data and C.S.I.R. for a research fellowship to J.V.  相似文献   

11.
Summary Gonadectomy, or injections of testosterone or 17- estradiol, had no apparent effect on the rate of regeneration or histological appearance of limb regenerates in the newt,Notophthalmus viridescens. Neither promotion, nor inhibition of limb regeneration was observed.This work was supported by a grant from the National Research Council of Canada to S.R.S.  相似文献   

12.
Summary On the basis of comparative chemical and spectral data, the structure of the major saponin, luzonicoside, from the starfishEchinaster luzonicus has been elucidated as2. This is a further example of a novel class of steroidal cyclic glycoside from starfish of the genusEchinaster. Its structure includes a 7, 3,6-dioxygenated-23-oxosteroidal moiety, already found in the saponins ofEchinaster sepositus, and a trisaccharide moiety, -D-galactopyranosyl-(12) -L-arabinopyranosyl-(12)--D-glucuronopyranosyl, bridging C-3 and C-6 of the steroid.This contribution is part of the Progetto Finalizzato Oceanografia e Fondi Marini del C.N.R., Roma.Acknowledgments. We wish to thank Mrs M. Pusset, Laboratoire des Plantes Médicinales du C.N.R.S., Nouméa, for the extraction of starfish and the divers of the Centre Q.R.S.T.O.M. de Nouméa for collection.  相似文献   

13.
Zusammenfassung Es werden Einzelheiten für den Gebrauch von Spirostan und Furostan, wenn nötig durch die Präfixe 5, 5, 25R und 25S modifiziert, für die Benennung der Steroid-Sapogenine bekanntgegeben. Diese Vorschläge sollen als formale Grundlage zur Nomenklatur gelten.

A summary of the personal views of the authors, Presented by the authors to anad hoc Committee on Steroid Nomenclature (sponsored by the National Academy of Sciences and the National Research Council, and supported by a grant from the U.S. Air Force Office of Scientific Research) that met in Columbus, Ohio, October 13–15, (1961), under the chairmanship ofR. C. Elderfield.  相似文献   

14.
Summary Hexoprenaline potentiated the14C-aminopyrine uptake (a reliable index of H+ generation) of isolated rat gastric cells stimulated by 10–6–10–4 mol/l carbachol, and inhibited that in response to 10–4 mol/l histamine without and in the presence of propranolol. It is concluded that hexoprenaline acts as a partial agonist on parietal cell H2-receptors and that -adrenoceptor activation may functionally modualte gastric acid secretion.Acknowledgments. S. Maliski, Institute of Rheumatology, Warszawa, held a fellowship of the Alexander v. Humboldt-Foundation. The study was supported by the Deutsche Forschungsgemeinschaft. The skilful technical assistance of Mrs R. Maier and Mr R. Beer is gratefully acknowledged.  相似文献   

15.
Summary Viable cerebellar perikarya of mixed cell type obtained from 7–9-day-old rats were maintained in monolayer culture for up to 12 days. During this time extensive neurite formation and outgrowth occurred. The large majority of the cells developing in culture were tentatively identified as granule neurons. This identification was based on the large number isolated from the starting tissue, and the cells general morphological features in culture such as perikaryal and nuclear size, the bipolar nature of neurite extension, and their migratory behaviour.D.N. Currie was supported by a grant from Hoechst Pharmaceuticals, Ld, U.K.J.C. was supported by an S.R.C. Grant to S.P.R. RoseThe authors would like to thank Kathleen Tear for excellent technical assistance and members of the Brain Research Group for helpful discussions.  相似文献   

16.
Summary The chlorophyll a and protein contents of invertebrates containing autotrophic symbionts are indices of symbiont and host biomass, respectively, and the chlorophyll a content per unit protein is a good measure of symbiont: host ratio. For three different associations, the chlorophyll a content per unit protein is 0.01–0.02 g g–1.The hydra andE. viridis were provided by M. H. Christopher and J. R. Turner. I thank Professor D. C. Smith, Dr J. B. Searle and Dr T. A. V. Rees for the valuable comments on drafts of this paper. This work was supported by research grants from S.E.R.C.  相似文献   

17.
Summary Highly purified human 2 macroglobulin (1.2–10 mg/ml) was shown to inhibit phytohemagglutinin-induced or antibody-induced lysis of chicken erythrocytes by polymorphonuclear neutrophils. Inhibition was not associated with impaired contact between effector and target cells but rather with the antiprotease activity of 2 macroglobulin.This study was supported by D.G.R.S.T. contract No 77-7-1381.  相似文献   

18.
Summary A monospecific antiserum has been prepared in rabbits against purified -antigen, a 100,000 mol.wt glycoprotein found on the surface of mouse L-cells. This antiserum has been employed to demonstrate the presence of -antigenic determinants selectively on the surface of mouse T-, but not B-lymphocytes.We thank Drs A. Christopher and R. Hunt for advice during the course of these studies. This work was supported by grants from the U.S. Public Health Service and the American Cancer Society.  相似文献   

19.
Summary Cyanidin-3--glucoside was shown to be an important factor of resistance in cottonGossypium hirsutum L. leaves to the tobacco budwormHeliothis virescens (Fab.). This provides a potential basis for achieving insect resistance in non-glanded cotton and other crops infested byHeliothis.In cooperation with the Mississippi Agriculture and Forestry Experiment Station, Mississippi State. Mention of a trademark, proprietary product or vendor does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.  相似文献   

20.
Riassunto I tre Sirenidi viventi hanno 46, 52 e 64 cromosomi; il corredo diS. lacertina sembra tetraploide (4n=52). Viene fatta l'ipotesi che anche i corredi delle altre due specie derivino per (allo-)poliploidia da corredi a minor numero cromosomico, come si ritrovano nelle famiglie superiori dell'Ordine.

Research carried out through a contribution from the C.N.R.  相似文献   

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