黑木耳种内杂交子的鉴定技术*

采用原生质体技术,获得黑木耳(Auricularia auricula)栽培菌株He-1的单核化菌株H1、H2、H3和栽培菌株Ju-1的单核化菌株J1、J2、J3,将H1、H2、H3分别与J1、J2、J3配对杂交,核相观察确认H2J1、H2J2和H2J3均为双核体。酯酶同工酶分析表明,H2J1、H2J2和H2J3不仅具有相应的亲本单核体共有的酶带,而且具有两个亲本各自的特异性标记酶带。RAPD分析表明,引物S30和S62对杂交子H2J1、H2J2和H2J3的扩增图谱中不仅包含相应的亲本单核体所共有的DNA带,而且包含亲本单核体各自的特异性DNA带。拮抗和栽培试验表明,杂交子H2J1、H2J2、H2J3与双核体亲本He-1和Ju-1的菌落之间有窄细的黑色拮抗线,子实体形态上有较明显差异。     

Rates and roles of cyclic and alternative electron flow in potato leaves

Measurements of 810 nm transmittance changes in leaves, simultaneously with Chl fluorescence, CO(2) uptake and O(2) evolution, were carried out on potato (Solanum tuberosum L.) leaves with altered expression of plastidic NADP-dependent malate dehydrogenase. Electron transport rates were calculated: J(C) from the CO(2) uptake rate considering ribulose-1,5-bisphosphate (RuBP) carboxylation and oxygenation, J(O) from the O(2) evolution rate, J(F) from Chl fluorescence parameters and J(I) from the post-illumination re-reduction speed of PSI donors. In the absence of external O(2), J(O) equaled (1.005 +/- 0.003) J(C), independent of the transgenic treatment, light intensity and CO(2) concentration. This showed that nitrite and oxaloacetate reduction rates were very slow. The Mehler-type O(2) reduction was evaluated from the rate of electron accumulation at PSI after the O(2) concentration was decreased from 210 to 20 mmol mol(-1), and resulted in <1% of the linear flow. J(F) and J(I) did not differ from J(C) while photosynthesis was light-limited, but considerably exceeded J(C) at saturating light. Then, typically, J(F) = 1.2 J(C) and J(I) = 1.3 J(C), and J(F) -J(C) and J(I) -J(C) depended little on CO(2) and O(2) concentrations. The results showed that the alternative and cyclic electron flow necessary to compensate variations in the ATP/NADPH ratio were only a few percent of the linear flow. The data do not support the requirement of 14H(+)/3ATP by the chloroplast ATP synthase. We suggest that the fast PSI cyclic electron flow J(I) - J(C), as well as the fast J(F) - J(C) are energy-dissipating cycles around PSI and PSII at light saturation.     

Variations in the amount of glucose phosphate isomerase in lymphocytes and erythrocytes from A/J and C57BL/6J mice

In a comparative study of A/J (Gpi-1a) and C57BL/6J (Gpi-1b) mice, we observed that erythrocytes of A/J mice exhibited significantly higher glucose phosphate isomerase (GPI) activity compared to erythrocytes of C57BL/6J mice on a per cell, per gram of protein, or per gram of hemoglobin basis. Higher GPI activity per cell was detected for peripheral blood lymphocytes of A/J compared to C57BL/6J mice. (A/J X C57BL/6J)F1 mice expressed erythrocyte and peripheral blood lymphocyte GPI activities intermediate to those of the parental mouse strains. The GPI activities of spleen lymphocytes from A/J, C57BL/6J, or (A/J X C57BL/6J)F1 mice were not significantly different from each other. The higher activity in the A/J mice could be due to GPI of a higher catalytic rate or to the presence of more GPI molecules. In order to distinguish these two possibilities, GPI was purified to homogeneity from both strains of mice. The specific activities (activity per milligram of protein) of the purified enzymes from the two strains were found to be similar, indicating that GPI from the A/J strain was not a more active enzyme. Antibody to the purified enzymes was prepared and used in an enzyme-linked immunosorbent assay (ELISA) to compare the relative amounts of enzyme molecules in cells of A/J and C57BL/6J mice. Results of the ELISA tests on peripheral blood lymphocytes indicated that A/J mice contain more molecules of GPI per cell and, therefore, have a higher GPI activity than C57BL/6J mice.     

Acquisition of endogenous ecotropic MuLV can occur before the late one-cell stage in the genital tract of SWR/J-RF/J hybrid females

Endogenous ecotropic MuLV proviral loci are acquired by the progeny of some [SWR/J x (SWR/J x RJ/J)F1] N2 hybrid females obtained by two successive backcrosses of RF/J mice onto the SWR/J background. This results most likely from an infection of early embryos or oocytes by MuLV particles originating from maternal tissues. However, the time and site of infection are not yet known. Using oviductal transfers of embryos at the one-cell stage, we show here that three of 88 N3 embryos from [SWR/J x (SWR/J x RF/J)F1] N2 hybrid females transferred to virus-free foster mothers harbored new proviral integrations, whereas none of 61 SWR/J embryos transferred to [SWR/J x (SWR/J x RF/J)F1] N2 hybrid females had acquired any proviruses. These data support the infection of oocyte and/or early one-cell embryo as the initial event leading to new proviral insertions.     

The rabbit kappa 1 b5 immunoglobulin gene: another J region gene cluster with only one functional J gene segment?

Our previous analysis of an immunoglobulin gene encoding the rabbit kappa chain of b4 allotype revealed that of the five J-like sequences in the J kappa cluster of this gene, only one, J2, appeared to be functional. This unusual ratio of J pseudogenes to functional J genes is unique among all J clusters of light and heavy chain genes of all species examined to date, including the cluster from the rabbit kappa 2 isotype, and must have consequences for diversity generation of b4 immunoglobulins. The fact that the only two known b5 J kappa sequences are different from the functional J2 of the b4 allotype prompted investigation of the b5 J kappa cluster to determine whether it resembled the b4 cluster, or the more typical mouse or human J kappa clusters. Our analysis of the b5 gene reveals a J kappa cluster strikingly similar to that of b4; apparent defects occur in all J sequences except J2. Although J2 is apparently functional, it differs from the J2 of the b4 locus by four nucleotide and three amino acid substitutions. The unusually high degree of sequence similarity previously observed between the b4 and b5 loci in the noncoding (vs the coding) regions extends through the newly sequenced DNA segment and remains an enigma.     

Taxonomic revision of Joyeuxilepis Spassky, 1947 (Cestoda: Amabiliidae): redescriptions of J. biuncinata (Joyeux & Baer, 1943), J. decacantha (Fuhrmann, 1913) and J. pilatus Borgarenko & Gulyaev, 1991

Two species of Joyeuxilepis Spassky, 1947 are redescribed from Tachybaptus ruficollis in Bulgaria: J. biuncinata (Joyeux & Baer, 1943) and J. pilatus Borgarenko & Gulyaev, 1991. The syntypes of J. decacantha (Fuhrmann, 1913) from Podiceps cristatus in Sweden and voucher specimens of J. pilatus (identified as 'Tatria decacantha') from T. ruficollis in England (new geographical record) from the British Museum (Natural History) Collection are also re-described. The voucher specimens and cysticercoids of Tatria spp. from dragonfly nymphs in Wales recorded by Rees (1973) were re-examined. Previous records of J. biuncinata, J. decacantha and J. pilatus are critically analysed in view of the present results. The major reliable diagnostic characters for species of Joyeuxilepis are presented and the distinguishing criteria for the three species studied are re-evaluated.     

The transfer of bovine J blood group activity to erythrocytes: chemical nature of transferable and of non-transferable J1

The bovine J blood group substance exists as a glycosphingolipid (ceramide deca-hexoside as well as ceramide dodecahexoside) and as a glycoprotein. The lipidic form occurs in erythrocyte membranes, both forms are found in serum. The lipidic J substances were isolated from erythrocytes and from serum, and identified by thin-layer chromatography with lipidic J substances isolated from spleen. The glycoprotein nature of the non-lipidic J of serum was evident by pronase-catalysed hydrolysis yielding J-active glycopeptides of lower molecular weights. The lipidic J was completely extracted from lyophilized stroma with chloroform/methanol. From lyophilized serum, however. it was completely extracted only in the presence of water, indicating different binding partners in serum and in erythrocyte membranes. The J lipid was incorporated as intact molecule into the erythrocyte membrane by a simple incubation technique. The incorporation was inhibited by various glyc-erophospholipids (called blockers). The J glycoprotein could not be transferred to the erythrocyte membrane. Three methods are descrjbed which are suitable for the preparation of a blocker-free fraction enriched with J lipids from J-positive serum.     

RAPD DNA fingerprints and terpenoids: clues to past migrations of Juniperus in Arabia and east Africa

Random amplified polymorphic DNAs (RAPDs) and leaf volatile terpenoids were used to compare junipers from Abha, Saudi Arabia with J. excelsa from Greece and J. procera from Addis Ababa, Ethiopia. Both the RAPDs and terpenoids clearly identified the Abha juniper as J. procera. The migration and evolution of J. excelsa or pre-J. excelsa junipers southward from Asia Minor into Africa is discussed. A computer program, PCO3D, is now available for 3-D ordination of RAPDs data. In addition, this research supports the recognition of both J. excelsa and J. procera as separate species.     

Macronutrient diet selection in thirteen mouse strains

The strain distribution for macronutrient diet selection was described in 13 mouse strains (AKR/J, NZB/B1NJ, C57BL/6J, C57BL/6ByJ, DBA/2J, SPRET/Ei, CD-1, SJL/J, SWR/J, 129/J, BALB/cByJ, CAST/Ei, and A/J) with the use of a self-selection protocol in which separate carbohydrate, fat, and protein diets were simultaneously available for 26-30 days. Relative to carbohydrate, nine strains consumed significantly more calories from the fat diet; two strains consumed more calories from carbohydrate than from fat (BALB/cByJ, CAST/Ei). Diet selection by SWR/J mice was variable over time, resulting in a lack of preference. One strain (A/J) failed to adapt to the diet paradigm due to inadequate protein intake. Comparisons of proportional fat intake across strains revealed that fat selection/consumption ranged from 26 to 83% of total energy. AKR/J, NZB/B1NJ, and C67BL/6J mice self-selected the highest proportion of dietary fat, whereas the CAST/Ei and BALB/cByJ strains chose the lowest. Finally, epididymal fat depot weight was correlated with fat consumption. There were significant positive correlations in AKR/J and C57BL/6J mice, which are highly sensitive to dietary obesity. However, absolute fat intake was inversely correlated with epididymal fat in two of the lean strains: SWR/J and CAST/Ei. We hypothesize that the SWR/J and CAST/Ei strains are highly sensitive to a negative feedback signal generated by increasing body fat, but the AKR/J and C67BL/6J mice are not. The variation in dietary fat selection across inbred strains provides a tool for dissecting the complex genetics of this trait.     

Prenatal transmission and pathogenicity of endogenous ecotropic murine leukemia virus Akv.

OBJECTIVE: Mouse strains carrying endogenous ecotropic murine leukemia viruses (MuLV) are capable of expressing infective virus throughout life. Risk of transplacental transmission of MuLV raises concerns of embryo infection and induction of pathogenic effects, and postnatal MuLV infection may lead to tumorigenesis. METHODS: Endogenous ecotropic MuLV-negative SWR/J embryos were implanted into Akv-infected viremic SWR/J mice, into spontaneously provirus-expressing AKR/J mice, and into noninfected SWR/J control mice; virus integration and virus expression were investigated at 14 days' gestation. Tumor development was monitored over 18 months. RESULTS: Of 111 embryos, 20 (18%) recovered from Akv-infected SWR/J mice, which had developed normally, were infected. New proviruses were detected in 10 of 111 (9%) embryos from Akv-infected SWR/J mice, and in 2 of 60 (3%) embryos from AKR/J mice; none expressed viral protein. Of 127 embryos recovered from Akv-infected SWR/J mice, 16 (13%) were dead; 4 of 5 (80%) were infected and expressed viral protein. Of 71 embryos from AKR/J mice, 11 (15%) were dead, and 2 of 2 had virus integration; virus expression was not detected. Numbers of dead embryos recovered from experimentally infected, viremic SWR/J mice and from spontaneously endogenous MuLV-expressing AKR/J mice were significantly higher, compared with numbers from nonviremic SWR/J control mice, and embryo lethality was significantly associated with prenatal provirus expression. Postnatal inoculation of Akv induced lymphoblastic lymphomas in 15 of 24 (61%) SWR/J mice within mean +/- SD latency of 14 +/- 2.4 months. Only 3 of 39 (8%) control mice developed lymphomas (P < 0.005). CONCLUSION: Embryos in MuLV-viremic dams are readily infected, and inappropriate prenatal expression of leukemogenic endogenous retroviruses may play a critical role in embryo lethality and decreased breeding performance in ecotropic provirus-positive mouse strains.     

A synopsis of the Juncus hesperius group (Juncaceae, Juncotypus) and their hybrids in western North America

A synopsis of North American species in the Juncus hesperius group is presented. Juncus exiguus, J. hesperius, and J. laccatus form a trio of closely related species in the section Juncotypus, restricted to western North America. They are illustrated and mapped based on extensive field and herbarium studies. A key to North American members of Juncus section Juncotypus, north of Mexico, is presented. Putative hybrids in the group are morphologically intermediate and rare in mixed populations. The following putative hybrid combinations are documented: J. exiguus × J. effusus subspecies pacificus from California; J. exiguus × J. laccatus from California; J. hesperius × J. effusus subspecies pacificus from British Columbia, California, and Washington; J. hesperius × J. laccatus from Washington, and J. hesperius × J. patens from California. Three putative hybrids are illustrated.     

J1/tenascin in substrate-bound and soluble form displays contrary effects on neurite outgrowth

The influence of J1/tenascin adsorbed to polyornithine-conditioned plastic (substrate-bound J1/tenascin) and J1/tenascin present in the culture medium (soluble J1/tenascin) on neurite outgrowth was studied with cultured single cells from hippocampus and mesencephalon of embryonic rats. Neurons at low density grew well on J1/tenascin substrates and extended neurites that were approximately 40% longer than on the polyornithine control substrate after 24 h in vitro. The neurite outgrowth promoting effect of substrate bound J1/tenascin was largely abolished in the presence of mAb J1/tn2, but not by mAb J1/tn1. In contrast to the neurite growth-promoting effects of substrate bound J1/tenascin, neurite outgrowth on polyornithine, laminin, fibronectin, or J1/tenascin as substrates was inhibited by addition of soluble J1/tenascin to the cultures. Neither of the two mAbs neutralized the neurite outgrowth-inhibitory properties of soluble J1/tenascin. In contrast to their opposite effects on neurite outgrowth, both substrate-bound and soluble J1/tenascin reduced spreading of the neuronal cell bodies, suggesting that the neurite outgrowth-promoting and antispreading effects are mediated by two different sites on the molecule. This was further supported by the inability of the mAb J1/tn2 to neutralize the antispreading effect. The J1/tn2 epitope localizes to a fibronectin type III homology domain that is presumably distinct from the putative Tn68 cell-binding domain of chicken tenascin for fibroblasts, as shown by electronmicroscopic localization of antibody binding sites. We infer from these experiments that J1/tenascin contains a neurite outgrowth promoting domain that is distinguishable from the cell-binding site and presumably not involved in the inhibition of neurite outgrowth or cell spreading. Our observations support the notion that J1/tenascin is a multifunctional extracellular matrix molecule.     

Development of in vivo somatic mutation system using antibody against hemoglobin Preparation and use of an anti-hemoglobin antibody for identifying C57BL/6 red cells in artificial mixture of DBA/2 and C57BL/6 red cells

A cellular specific-locus mutation test is described for detecting mutant cells in mammals. The test is based upon the use of specific anti-C57BL/6J mouse hemoglobin antibody that binds hemoglobin “single” (hemoglobin s, present in C57BL/6J mouse) and not hemoglobin “diffuse” (hemoglobin d, present in DBA/2J mouse). Attempts to purify such antibody from pony and rabbit antisera through cross-absorption were unsuccessful. Immunization of LP/J mouse with C57BL/6J hemoglobin produced antiserum that reacted with s hemoglobin but not with d hemoglobin. In a fluorescent antibody technique, this antibody was found to label fixed red blood cells from C57BL/6J mice but not from DBA/2J mice. In a mixture of C57BL/6J and DBA/2J red cells, the C57BL/6J cells could be differentiated by their bright fluorescence from the non-fluorescent DBA/2J cells. Reconstruction experiment with artificial mixtures of DBA/2J and C57BL/6J cells showed that s hemoglobin bearing cells could be detected in DBA/2J red cells at frequencies as small as 0.4×10^?6. Thus, the system is sensitive enough to detect d → s mutation in DBA/2J mice. Amino acid comparison of the globin chains of s and d hemoglobins shows that our antibody can probably detect mutations leading to a substitution of serine or proline by alanine at β²⁰ position and/or a substitution of threonine by alanine at β¹³⁹ position.     

Molecular characterization and RAPD analysis of Juniperus species from Iran

The genus Juniperus L. (Cupressaceae), an aromatic evergreen plant, consists of up to 68 species around the world. We classified five species of Juniperus found in Iran using molecular markers to provide a means for molecular identification of Iranian species. Plants were collected (three samples of each species) from two different provinces of Iran (Golestan and East Azarbayejan). The DNA was extracted from the leaves using a Qiagen Dneasy Plant Mini Kit. Amplification was performed using 18 ten-mer RAPD primers. Genetic distances were estimated based on 187 RAPD bands to construct a dendrogram by means of unweighted pair group method of arithmetic means. It was found that J. communis and J. oblonga were differentiated from the other species. Genetic distance values ranged from 0.19 (J. communis and J. oblonga) to 0.68 (J. communis and J. excelsa). Juniperus foetidissima was found to be most similar to J. sabina. Juniperus excelsa subspecies excelsa and J. excelsa subspecies polycarpos formed a distinct group.     

Genetic variation in chloroplast and nuclear ribosomal DNA in Utah juniper (Juniperus osteosperma, Cupressaceae): evidence for interspecific gene flow

Geographic patterns of genetic variation in chlorolast (cpDNA) and nuclear ribosomal (nrDNA) DNA were examined to test the hypothesis of hybridization between Juniperus osteosperma and Juniperus occidentalis in the Great Basin of western Nevada. Noncoding DNA from the trnL-trnF intergenic spacer and the trnL intron of the chloroplast genome was sequenced from seven populations of J. osteosperma and four populations of J. occidentalis sampled over a large proportion of their respective ranges. An adenine nucleotide at position 436 in the aligned sequence and within a Tru 9I restriction site was found to be present in individuals of J. osteosperma sampled from western Colorado and central Utah, but absent in sequences of J. osteosperma sampled from central and western Nevada and all sequences of J. occidentalis. Two hundred fourteen individuals from 34 populations of J. osteosperma and J. occidentalis were then screened for cpDNA haplotype by Tru 9I digestion of the trnL-trnF polymerase chain reaction (PCR) product. Two cpDNA haplotypes were evident, each consisting of restriction fragment profiles that differed solely with respect to the presence or absence of the Tru 9I site encompassing the adenine nucleotide at position 436. One of these haplotypes was monomorphic in J. occidentalis and exhibited a decreasing frequency in J. osteosperma with increasing geographic distance from J. occidentalis in west-central Nevada. Geographic patterns in nuclear ribosomal DNA (nrDNA) variation were examined by restriction fragment analysis and, although spatially more restricted, exhibited patterns of clinal variation similar to those observed in cpDNA haplotype. Genetic relationships based on DNA sequences and geographic patterns of genetic variation in chloroplast and nuclear ribosomal DNA are consistent with morphology in suggesting interspecific gene flow between J. occidentalis and J. osteosperma.     

Diastereoisomeric saponins from Albizia julibrissin

The structures of four new diastereoisomeric triterpenoidal saponins Julibroside J5, J8, J12 and J13 (1-4) isolated from Albizia julibrissin Durazz. (Leguminosae) have been determined on the basis of comprehensive spectroscopic analysis and chemical degradation. Julibroside, J8 and J13 showed marked cytotoxic activities against Bel-7402 cancer cell line at 100 microg/mL.     

Fibroblast-Derived J 1 Adhesion Glycoproteins Show Binding Properties to Extracellular Matrix Constituents Different from Those of Central Nervous System Origin

The J1 extracellular adhesion molecule from mouse brain consists of several immunochemically related glycoproteins of different molecular weights and distinct functional properties. Like the brain J1 glycoproteins, the fibroblast-derived J1 glycoproteins interact with all collagen types tested (collagen G and types I-IV and IX), as measured by binding of 125I-labeled J1 glycoproteins to immobilized collagens. As tested for collagen type I, this binding can be inhibited more effectively by chondroitin sulfate than by heparin. After electrophoretic separation and transfer to nitrocellulose, fibroblast-derived J1 only binds to a limited number of collagen types (collagen types I, VI, and IX and G), whereas brain-derived J1 glycoproteins bind to all collagen types tested (collagen types I-VI and IX and G). These results show that fibroblast-derived J1 glycoproteins, although immunochemically related to J1 glycoproteins from brain, differ from these in their binding specificities to extracellular matrix constituents.     

Contribution to the chromosome numbers of some species of the genus Juncus L. in Slovakia

The study presents chromosome counts of the following species of the genusJuncus from Slovakía:J. sphaerocarpus, J. capitatus, J. subnodulosus, J. atratus, J. alpino-articulatus subsp.alpino-articulatus, J. triglumis, J. castaneus.