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1.
The mechanical properties of various differentiated regions of thePorphyra perforata thallus and the effect of LiCl were studied by performing compression and tension tests. Among the various differentiated tissues, the holdfast area was high in its compressive modulus of elasticity and tensile modulus of elasticity, possibly related to its thick matrix. Vegetative non-dividing tissue and vegetative dividing tissue were the most flexible and strong, showing the highest percentage elongation at break and tensile strength. The patch area, which is a transition zone leading to sexually mature tissue, had moderate values of tensile properties. Meanwhile, sexually differentiated male and female tissues had the highest compressive modulus of elasticity and lowest tensile properties. Thes tisues tended to crumble easily. Treatments in LiCl, as used for DNA extraction, resulted in a decrease in both compressive modulus of elasticity (87%) and tensile modulus of elasticity (54%). After treatment of tissue for chromosome staining in a method using LiCl, there was a marked decrease in tensile modulus of elasticity (49%), while the compressive modulus of elasticity remained unchanged. Such mechanical changes verify the softening effect of LiCl on the seaweedP. perforata tissue.Author for correspondence  相似文献   

2.
Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F2 progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.  相似文献   

3.
Summary The three haploid yeast strains T2tmp1-3, T2tmp1-1, and T6tmp1-51 auxotrophic for 5-dTMP differ in their requirement for thymidylate: 72, 16, and 3 g 5-dTMP/ml will restore optimal growth, respectively. Thymidylate low requirement in strain T2tmp1-1 and T6tmp1-51 is termed tlrA and tlrC, respectively. When the growth medium is made 5x10-4 M for 5-dTMP only strain T6tmp1-51 is severely inhibited in RNA and DNA synthesis. This inhibition is reversible after removal of excessive 5-dTMP. The inhibitory characteristic is in marked contrast to thymineless death due to the lack of 5-dTMP in strain T6tmp1-51 where only DNA synthesis stops while RNA synthesis continues. The inhibitory effect of 5x10-4 M 5-dTMP is not due to the 5-dTMP auxotrophy but to the thymidylate low requiring character (tlrC) in strain T6tmp1-51. The arrest of RNA and DNA synthesis by high concentrations of exogenous 5-dTMP suggests a regulatory role of either the monoor triphosphate on nucleoside or nucleotide biosynthesis in yeast.  相似文献   

4.
In order to study the effect of glycosylation on its biological activities and to develop IL-1 with less deleterious effects, N-acetylneuraminic acid (NeuAc) with C9 spacer was chemically coupled to human recombinant IL-1. NeuAc-coupled IL-1 (NeuAc-IL-1) exhibited reduced activities in vitro and receptor-binding affinities by about ten times compared to IL-1. In this study, we examined a variety of IL-1 activities in vivo. NeuAc-IL-1 exhibited a marked reduction in the activity to up-regulate serum IL-6, moderate reduction in the activities to up-regulate serum amyloid A and NOx. However, it exhibited comparable activities as IL-1 to down-regulate serum glucose and to improve the recovery of peripheral white blood cells from myelosuppression in 5-fluorouracil-treated mice. In addition, tissue level of NeuAc-IL-1 was high compared to IL-1. These results indicate that coupling with NeuAc enabled us to develop neo-IL-1 with selective activities in vivo and enhanced tissue level.  相似文献   

5.
-Synuclein, a presynaptic protein of the central nervous system, has been implicated in the synaptic events such as neuronal plasticity during development and learning, and neuronal degeneration under pathological conditions. As an effort to understand the biological function of -synuclein, we examined the expression patterns of -synuclein in various human hematopoietic cells, and in Drosophila at different developmental stages. The -synuclein was ubiquitously expressed in all the tested hematopoietic cells including T cells, B cells, NK cells, and monocytes, as well as in the lymphoma cell lines, Jurkat and K562. A potential -synuclein homologue was also expressed in Drosophila, and its expression appeared to be temporally and spatially regulated during development. Our data suggest that -synuclein may function in invertebrates as well as in vertebrates and its function may not be restricted to the neuron.  相似文献   

6.
Members of the tumor necrosis factor (TNF) receptor (TNFR) superfamily are known to be potent mediators of immune responses. LIGHT is a member of the TNF superfamily, and its receptors have been identified as lymphotoxin receptor (LTR), herpes virus entry mediator (HVEM), and decoy receptor 3 (DcR3). LIGHT can induce either cell death and/or NF-B activation via its interaction with LTR and/or HVEM. In this study, we investigated the effects of LIGHT in human umbilical vein endothelial cells (HUVECs). We demonstrated that both LTR and HVEM, but not DcR3, are present in HUVECs, and LIGHT can induce the secretion of chemokines (IL-8 and GRO-), cell surface expression of adhesion molecules (ICAM-1 and VCAM-1), PGI2 release, and COX-2 expression. However, the LIGHT mutein, LIGHT-R228E, which has been shown to exhibit binding specificity to LTR, could not induce the secretion of GRO-, PGI2, or the expression of COX-2. These results indicate that both LTR and HVEM can discriminatively mediate the expression of different genes in HUVECs, and suggest that LIGHT is a proinflammatory cytokine.  相似文献   

7.
The enzyme, desacetoxyvindoline 4-hydroxylase, was purified to apparent homogeneity from Catharanthus roseus by ammonium sulfate precipitation and successive chromatography on Sephadex G-100, green 19-agarose, hydroxylapatite, -kg sepharose and Mono Q. The 4-hydroxylase was characterized by its strict specificity for position 4 of desacetoxyvindoline suggesting it to catalyze the second to last step in vindoline biosynthesis. The molecular mass of the native and denatured 4-hydroxylase was 45 kDa and 44.7 kDa, respectively, suggesting that the native enzyme is a monomer. Two-dimensional isoelectric focusing under denaturing conditions resolved the purified 4-hydroxylase into three charge isoforms of pIs 4.6, 4.7 and 4.8. The purified 4-hydroxylase exhibited no requirement for divalent cations, but inactive enzyme was reactivated in a time-dependent manner by incubation with ferrous ions. The enzyme was not inhibited by EDTA or SH-group reagents at concentrations up to 10 mM. The mechanism of action of desacetoxyvindoline 4-hydroxylase was investigated. The results of substrate interaction kinetics and product inhibition studies suggest an Ordered Ter Ter mechanism where -kg is the first substrate to bind followed by the binding of O2 and desacetoxyvindoline. Their K m values for -kg, O2 and desacetoxyvindoline are 45 M, 45 M and 0.03 M, respectively. The first product to be released was deacetylvindoline followed by CO2 and succinate, respectively.Abbreviations -kg -ketoglutarate or 2-oxoglutarate - NMT N-methyltransferase - SAM S-adenosyl-l-methionine - TLC thin layer chromatography - VBL vinblastine - VCR vincristine  相似文献   

8.
The gene encoding 5 3 exonuclease domain-deleted Tfi DNA polymerase, named 5 3 Exo Tfi fragment, from Thermus filiformis was expressed in Escherichia coli under the control of the tac promoter on a high-copy plasmid, pJR. The expressed enzyme was purified 27-fold with a 19% yield and a specific activity of 2621 U mg–1 protein. The 5 3 exonuclease domain of Tfi DNA polymerase was removed without significant effect on enzyme activity and stability. PCR conditions for the 5 3 Exo Tfi fragment were more tolerant to the buffer composition as compared to the full-length enzyme.  相似文献   

9.
A simple method for stimulating and maintaining high in vitro multiplication of Narcissus shoot clump cultures was developed. Shoot clumps were subjected either to normal cutting where leaves were trimmed to 20 mm in length at the beginning of each culture passage or to severe cutting where shoot clumps were cut down to the basal plate region removing all green tissue. Severe cutting at the beginning of each culture passage initially doubled the leaf multiplication, compared to normal cutting, but the difference between cutting treatments declined in successive passages. The improvement in leaf multiplication was maintained when shoot clumps were subjected to severe cutting only at every other culture passage, with no cutting in the alternate recovery passages. In vitro multiplication was increased by severe cutting in all seven Narcissus cultivars which were tested.Abbreviations NAA-1 naphthylacetic acid - BAP benzylaminopurine  相似文献   

10.
Summary Thirteen maize (Zea mays L.) populations including five adapted, five adapted x exotic, two composites of adapted and exotic, and one exotic selected for adaptability were crossed in a diallel mating system. The parents and 78 crosses and nine check hybrids were evaluated for grain yield and plant height in five environments. The Gardner-Eberhart model Analysis II indicated that additive and nonadditive gene effects accounted for 60 and 40% of the total variation among populations, respectively, for grain yield and 86% and 14% of the total variation, respectively, for plant height. Components of heterosis were significant in the combined analysis for both traits. Adapted Corn Belt populations tended to have higher performance in crosses and greater values of variety heterosis than 50% adapted populations. Nebraska Elite Composite, Corn Belt x Mexican, and Corn Belt x Brazilian showed high mean yields in crosses, however, they were not among those with high estimates of variety heterosis. One exotic population (Tuxpeno x Antigua Grupo 2) and three adapted populations [307 Composite, NB(S1)C-3, and NK(S1)C-3] might be combined together to form a high-yielding population. It may be possible to synthesize two useful populations for reciprocal recurrent selection by grouping Tuxpeno x Antiqua Grupo 2, NB(S1)C-3, and NS(FS)LFW-8 into one population and NK(S1)C-3, KrugxTabloncillo, and 307 Composite in the other one.Contribution from the Department of Agronomy, University of Nebraska, Lincoln, NE 68583. Published as Paper No. 8011. Journal Series, Nebr. Agric. Exp. Station. Research was conducted under Project 12-049  相似文献   

11.
Summary A mutant strain of Rhodococcus equi accumulates three metabolites from the androst-4-ene-3,17-dione or from its degradation intermediate, 3a-H-4(3'-propionic acid)-7a-methylhexahydro-1,5-indanedione (MEPHIP). These three metabolites are: 3a-H-4a(3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone--lactone (HIL); 3a-H-4(3'-trans acrylic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (2'-5-hydroxy-MEPHIP); and 3a-H-4(3'-hydroxy-3'-propionic acid)-5-hydroxy-7a-methylhexahydro-1-indanone (3'-hydroxy-HIL). The behaviour of this mutant allows us to propose a pathway for degradation of the intermediates, methylperhydroindanone propionates. However, during this degradation, the side-chain propionate was eliminated by a-oxidation mechanism. Offprint requests to: A. Miclo  相似文献   

12.
Summary Short oligocytidylates can act as templates for the self-condensation of guanosine 5-phosphorimidazolide. In the absence of a catalytic metal ion or in the presence of Pb2+ a noticeable template effect is already observed with the dimer and the yield of long oligomers reaches a plateau with a hexamer template. Short templates give oligomers longers than the template length. The products are predominantly 2-5 linked for the Pb2+-catalyzed reaction while mixed linkages are observed in the uncatalyzed reaction.In the presence of Zn2+, a template effect is first observed with the pentamer and is maximal by the heptamer. The products are predominantly 3-5 linked. Oligomers shorter than or as long as the template are obtained in substantial yield, and longer products in much lower yields.Abbreviations G Guanosine - Gp guanosine 2(3)-phosphate - pG guanosine 5-phosphate - Gp! guanosine cyclic 2,3-phosphate - ImpG guanosine 5-phosphorimidazolide - ImpG* [8-14C]-guanosine 5-phosphorimidazolide - pGp 5-phosphoguanosine 2(3)-phosphate - G2pG guanylyl-[2-5]-guanosine - G3pG guanylyl-[3-5]-guanosine - ImpGpG 5-phosphorimidazolide of GpG - (pG)n (n = 2,3) oligomers of pG - GppG P1, P2-diguanosine 5-diphosphate - GppGpG 5-[guanosine 5-pyrophosphate] of GpG - NH2pG guanosine 5-phosphoramidate - (pG)4+ tetramer and higher oligoguanylates with 5 terminal phosphate - oligo(G) oligoguanylate - Cp cytidine 2(3)-phosphate - Cp! cytidine cyclic 2,3-phosphate - (Cp)n–1 Cp! (n= 2,3,4) oligocytidylates terminated by 5-OH groups and 2,3-cyclic phosphates - oligo(C) oligocytidylate - poly(C) polycytidylic acid - poly(U) polyuridylic acid - poly(C,G) random copolymer of C and G - BAP bacterial alkaline phosphatase (E. coli) - EDTA ethylenediaminetetraacetic acid - Rf chromatographic mobility  相似文献   

13.
Summary Endopeptidase zymograms of the translocation line Indis revealed the presence of several major and minor bands that had differential expression in coleoptile and seed tissues. While Indis lacks Ep-D1a, which is present in the parental cultivar Inia 66, it also may not express any of the Th. distichum bands. The Indis zymogram was found to be identical to that of an isogenic line of Inia 66 possessing Lr19. Since the absence of an Ep-D1a product appears to be linked to the 7DL translocation, it is possible to use the null condition as a marker for both the Lr19 or Indis translocations. The Indis translocation also did not show recombination with the cn-D1 chlorophyl mutant on 7DL, confirming that a part of 7D was involved. The results of a telocentric mapping experiment involving the 7D telosomes indicated that in Indis a chromosome segment from Th. distichum replaced a large section of 7DL of Inia 66.  相似文献   

14.
Summary Expression of -crystallin, a lens-specific protein, in 6-day-old chick embryonic brain cells was examined in situ and in vitro. The presence of minute amounts of -crystallin and its mRNA (-mRNA) in brain cells in situ was demonstrated by immunoblot and Northern blot analysis. In spreading cultures of the brain cells, -crystallin and -mRNA showed a significant increase from their in situ level. Immunohistological staining (peroxidase antiperoxidase) with monospecific anti-serum against -crystallin revealed that -producers were both epithelial cells and dendritic cells. Neither lentoidogenesis nor -crystallin expression was observed. Stimulation of -crystallin synthesis in cultured brain cells differed when compared with transdifferentiating cultures of neural retina cells. In the latter, -crystallin synthesis occurred concomitantly with differentiation of morphologically distinct lens cells containing -crystallin.  相似文献   

15.
In a previous study, cDNA microsatellite markers were described in apricot (Prunus armeniaca L.). Specific PCR primers were designed to amplify the microsatellite-containing regions from genomic DNA in different Prunus species. In the present work, cDNA microsatellite markers were developed in the hexaploid Prunus domestica L. species and polymorphism was ascertained in a segregating plum population. Co-dominant mendelian segregation of alleles was demonstrated and microsatellite polymorphism displayed up to 6 alleles per SSR locus per individual. Parentage lineage of three full-sib European plum cultivars (cv. Cacanska najbolja, Cacanska rana and Cacanska lepotica) was reconstructed by the analysis of the above nuclear SSR markers, completed by four chloroplastic microsatellite loci. The six most informative nuclear loci enabled discrimination between the three Cacak cultivars and unrelated individuals as well as the previously proposed parents, Wangenheim and Pozegaca. Data obtained support previous evidence that these cultivars originated from the Stanley cultivar. However, SSR analysis finally excluded Wangenheim as the other possible parent. Based on the results obtained with nuclear and chloroplast SSR loci, we propose the origin of those three Cacak cultivars in a cross between Stanley as the mother plant and Ruth gerstetter as the pollinator. Furthermore, we demonstrate the utility of these apricot SSR markers for genotype fingerprinting of the hexaploid plum cultivars.  相似文献   

16.
Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu.  相似文献   

17.
Crude extracts of Rhodospirillum rubrum catalyzed the formation of acid-volatile radioactivity from (35S) sulfate, (35S) adenosine-5-phosphosulfate, and (35S) 3-phosphoadenosine-5-phosphosulfate. An enzyme fraction similar to APS-sulfotransferases from plant sources was purified 228-fold from Rhodospirillum rubrum. It is suggested here that this enzyme is specific for adenosine-5-phosphosulfate, because the purified enzyme fraction metabolized adenosine-5-phosphosulfate, however, only at a rate of 1/10 of that with adenosine-5-phosphosulfate. Further, the reaction with 3-phosphoadenosine-5-phosphosulfate was inhibited with 3-phosphoadenosine-5-phosphate whereas this nucleotide had no effect on the reaction with adenosine-5-phosphosulfate. For this activity with adenosine-5-phosphosulfate the name APS-sulfotransferase is suggested. This APS-sulfotransferase needs thiols for activity; good rates were obtained with either dithioerythritol or reduced glutathione; other thiols like cysteine, 2-3-dimercaptopropanol or mercaptoethanol are less effective. The electron donor methylviologen did not catalyze this reaction. The pH-optimum was about 9.0; the apparent K m for adenosine-5-phosphosulfate was determined to be 0.05 mM with this so far purified enzyme fraction. Enzyme activity was increased with K2SO4 and Na2SO4 and was inhibited by 5-AMP. These properties are similar to assimilatory APS-sulfotransferases from spinach and Chlorella.Abbreviations APS adenosine-5-phosphosulfate - PAPS 3-phosphoadenosine-5-phosphosulfate - 5-AMP adenosine-5-monophosphate - 3-AMP adenosine-3-monophosphate - 3-5-ADP 3-phosphoadenosine-5-phosphate (PAP) - DTE dithiorythritol - GSH reduced glutathione - BAL 2-3-dimercaptopropanol  相似文献   

18.
Summary Specific antisera to -melanotropin (-MSH) and corticotropin (ACTH 1-39) were used to obtain immunocytochemical evidence for the differential localization of -MSH and ACTH in the secretory granules of corticotropes of rat anterior pituitary. The specificity of the antisera was established by binding 131I-labeled -MSH and ACTH 1-39 to their respective antisera. Double-labeling immunocytochemistry (for -MSH, ferritin; for ACTH, colloidal gold) was performed. Some secretory granules were labeled with ferritin particles (-MSH), whereas others contained gold particles (ACTH). Only a few granules showed both ACTH and -MSH. In typical corticotropes (stellate in form with a small number of secretory granules aligned along the cell periphery) only some of the secretory granules that were labeled with anti-ACTH serum were also immunoreactive to anti--MSH. In atypical corticotropes (polygonal in shape and containing a large number of secretory granules) almost all of the immunoreactive ACTH secretory granules were also positive to anti--MSH serum. An intermediate type of corticotrope was observed containing a small number of secretory granules, almost all of which were labeled with anti--MSH. Thus, rat anterior pituitary corticotropes may be classified into three types according to the distribution and content of -MSH. The light-microscopic immuncytochemistry provided similar results.  相似文献   

19.
Summary The inheritance of two mutants of flax (Linum usitatissimum), having altered proportions of the C18 polyunsaturated fatty acids, linoleic and linolenic, was examined. Both lines, M1589 and M1722, are homozygous for a single gene mutation which reduces linolenic acid content from 34% to 22% and raises linoleic acid from 15% to 27%. Genetic analysis of crosses involving M1589, M1722 and their parental cultivar Glenelg revealed that these mutations are in different unlinked genes and exhibit additive (codominant) gene action. The symbolsLn1 andLn2 are proposed for the mutated genes in M1589 and M1722, respectively. Recombinant genotypes homozygous for the mutant alleles at both loci are very low in linolenic acid (2%) and high in linoleic acid (48%), with unaltered proportions of other fatty acids. The complete inverse correlation between linoleic and linolenic acids (r=-0.98) indicates that the mutations block the synthesis of linolenic acid at the linoleic desaturation step.  相似文献   

20.
Résumé Nous avons fait élever des larves d'Anergates atratulus par des ouvrières deMyrmica laevinodis à 22°C. Pour y parvenir, il n'est pas utile de faire hivernerensemble les larves d'Anergates et les ouvrières deMyrmica. La présence de larves autochtones n'empêche pas lesMyrmica d'élever des larves d'Anergates. Dans toutes les expériences lesMyrmica ont été soumises au fridavant de recevoir des larves d'Anergates. Aucune reine deMyrmica n'a été utilisée dans ces expériences.Sur les 64 larves d'Anergates que nous avons utilisées, 38 se sont transformées en imagos. C'est au début de l'adoption et au moment des métamorphoses que périrent la plupart des 26Anergates perdus. Les femelles vécurent en général 2 ou 3 jours et cherchèrent très tôt à quitter le nid natal. Les mâles vécurent 2 à 3 semaines.
Summary Larvae ofAnergates atratulus were experimentally reared by workers ofMyrmica laevinodis, at 22°C. An overwintering of both larvae ofAnergates and workers ofMyrmica is not necessary for the success of that experiment. The presence of larvae ofMyrmica does not keep theMyrmica from rearing larvae ofAnergates. The workers ofMyrmica have been cooled, in all the experiments, before receiving larvae ofAnergates. No queen ofMyrmica have been used in that experiments.38 of the 64 larvae ofAnergates used became imagos. Most of the 26 lostAnergates died at the beginning of the adoption and during the metamorphosis. The females lived generally 2 or 3 days and tried, very early, to leave their native nest. The males lived 2 or 3 weeks.

Anergates atratulus Myrmica laevinodis, 22 . bmecme Anergates Myrmica. Myrmica Anergates. Myrmica Anergates. Myrmica . 64 Anergates , 38 . 26 Anergates 2 3 . 2 3 .
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