Reviews

Books reviewed in this article:
Root Development and Function. Ed. by P. J. G regory , J. V. L ake and D. A. R ose
Modern Methods in Plant Analysis. Volume 3. Gas Chromatography/Mass Spectrometry. Edited by H. F. L inskens and J. F. J ackson
Genetic Differentiation and Dispersal in Plants. Edited by P. J acquard , G. H eim and J. A ntonovics
Tropical Forest and its Environment . By K. A. L ongman and J. J enik
Ecology of Biological Invasions. Edited by R. H. G roves and J. J. B urdon
Ecology of Microbial Communities: 41st Symposium of The Society for General Microbiology. Ed. by M. F letcher , T. R. G. G ray and J. G. J ones     

Reviews

Transport of photoassimilates. Ed. by D. A. B aker and J. A. M ilburn.
Plant Lipids : Targets for Manipulation (British Plant Growth Regulator Group, Monograph No. 17). Ed. by N. J. P infield and A. K. S tobart.
Experimental Techniques in Plant Disease Epidemiology. Ed. by J. K ranz and J. R otem.
The Names of Plants. By D. G ledhill
Plant Form and Vegetation Structure. Ed. by M. J. A. W erger , P. J. M. V an der A art , H. J. D uring and J. T. A. V erhoeven.
Vegetation Structure in Relation to Carbon and Nutrient Economy. Ed. by J. T. A. V erhoeven , G. W. H eil and M. J. A. W erger .
Diversity and Pattern in Plant Communities. Ed. by H. J. D uring , M. J. A. W erger and J. H. W illems .     

Book reviews

Book reviews in This Article:
Detection of Bacterial Endotoxins with the limulus amebocyte lysate Test (1987). Edited by Stanley W. Watson, Jack Levin & Thomas J. Novitsky.
Computers in Microbiology (1987). Edited by J.D. Rant, R.K.A. Feltham & W. Shepherd.
Molecular Strategies of Parasite Invasion (1987). Edited by N. Agabian, H. Goodman & N. Nogueira.
Footrot in Ruminants (1986). Edited by D.J. Stewart, J.E. Peterson, N.M. McKern & D.L.
Bacterial Protein Toxins (1986). Edited by P. Falmagne, J.E. Alouf, F.J. Fehrenbach, J. Jeljaszewicz & M. Thelestam.
Carbon Substrates in Biotechnology (1987). Edited by J.D. Stowell, A.J. Beardsmore, C.W. Keevil & J.R. Woodward.     

Binding of the J 1 Adhesion Molecules to Extracellular Matrix Constituents

The J1 glycoproteins can be obtained in multiple forms in the soluble fraction of developing and adult mouse brain tissue. They are recovered as two forms of apparent molecular weights of 160,000 and 180,000 (J1-160) from adult mouse brain and as forms of apparent molecular weights of 200,000 and 220,000 (J1-220) from developing brain. J1-160 and J1-220 share common epitopes but are considered as separate entities, with J1-220 being immunochemically closely related if not identical to tenascin. Based on the observation that J1 immunoreactivity appears on basement membrane and interstitial collagens after denervation of the neuromuscular junction in adult rodents, we became interested in investigating the binding properties of J1 glycoproteins to extracellular matrix constituents in vitro. Both J1-160 and J1-220 bound to collagens type I-VI and IX but not to laminin, fibronectin, bovine serum albumin, or gelatin under hypotonic buffer conditions. Under isotonic buffer conditions, J1-220 bound to all collagen types, whereas J1-160 bound only to collagen types V and VI with values that could be examined by Scatchard analysis. Binding of J1-220 to collagens displayed two binding constants (KD) between 1.5 and 4.4 X 10(-9) and 1.8 and 5.5 X 10(-8) M, respectively, under hypotonic buffer conditions and a single KD of 2.1-8.0 X 10(-8) M under isotonic buffer conditions. Binding of J1-160 to collagens had an apparent KD of 1.9-8.0 X 10(-9) M under hypotonic buffer conditions. Under isotonic buffer conditions, binding constants of J1-160 to collagen types V and VI were approximately 2 X 10(-8) M. Binding of J1-220 to collagen type I could be inhibited by J1-220, J1-160, and collagen type VI but not by fibronectin or gelatin. Conversely, binding of J1-160 was inhibited by J1-220, J1-160, and collagen type VI (in order of decreasing efficacy of competition). J1-160 and J1-220 were retained on a heparin-agarose column and eluted in a salt gradient at approximately 0.5 M NaCl. The formation of the J1-heparin complexes was inhibited 100-fold more efficiently by heparin than by chondroitin sulfate. These experiments show that J1 glycoproteins resemble in many respects the extracellular matrix constituents fibronectin, laminin, vitronectin, and von Willebrand factor.     

J1-160 and J1-180 are oligodendrocyte-secreted nonpermissive substrates for cell adhesion

The glia-derived J1 extracellular matrix glycoproteins have been referred to as J1-160/J1-180 (the developmentally late appearing lower molecular weight group) and J1-200/J1-220 (the developmentally early appearing higher molecular group immunochemically related to tenascin). Members of the two groups show distinct cross-reactivities. To characterize the structural and functional differences between these J1 glycoproteins, two monoclonal antibodies were generated which recognize only the members of the lower molecular weight group. The two antibodies detect immunochemical similarities among the members of the lower molecular weight group, but do not react with J1/tenascin. J1-160 and J1-180 are specifically expressed by differentiated oligodendrocytes in culture and by myelin of the central nervous system and have not been found in the peripheral nervous system nor in any other organ of the adult mice tested. Electron microscopic examination of rotary-shadowed J1-160 and J1-180 reveals, respectively, dimeric and trimeric (tribrachion) kink-armed rodlike structures, which are linked by disulfide bridges. J1-160/J1-180 are nonpermissive substrates for the attachment and spreading of early postnatal small cerebellar neurons, astrocytes, and fibroblasts. In a mixture with laminin, J1- 160/J1-180 are nonpermissive substrates for neurons, but not for astrocytes or fibroblasts. The repulsive effect toward neurons can be neutralized by one of the monoclonal antibodies, but not by the other. These observations are discussed in the context of cell interactions during regeneration in the mammalian nervous system.     

Reviews

Book Reviewed in this article:
Carbon Partitioning within and between Organisms. Ed. by C.J. P ollock , J. F. F arrar & A. J. G ordon .
Mycorrhizas in Ecosystems. Ed. by D. J. R ead , D. H. L ewis , A. H. F itter & I. J. A lexander .
Methods in Comparative Ecology: a Laboratory Manual. Ed by G. A. F. H endry & J. P. G rime .
Climate Modes of the Phanerozoic. By L. A. F rakes , J. E. F rancis & J. A. S yktus .
The Evolution of Asexual Reproduction in Plants. By M. M ogie .     

Systematics of Juniperus section Juniperus based on leaf essential oils and random amplified polymorphic DNAs (RAPDs)

The composition of the leaf essential oils of all the species of Juniperus in sect. Juniperus (=sect. Oxycedrus) are reported and compared (J. brevifolia, J. cedrus, J. communis, J. c. var. saxatilis, J. c. var. oblonga, J. formosana, J. oxycedrus, J. o. subsp. badia, J. o. subsp. macrocarpa, J. o. subsp. transtagana, J. rigida, J. r. subsp. conferta, J. sibirica, J. taxifolia and J. t. var. lutchuensis). In addition, DNA fingerprinting by RAPDs was utilized. Based on these data, several taxa remained at the same taxonomic level: J. brevifolia, J. cedrus, J. communis, J. c. var. saxatilis, J. formosana, J. oxycedrus, J. rigida, J. r. var. conferta, and J. taxifolia. However, several taxa exhibited considerable differentiation that warranted their recognition at the specific level: J. oblonga M.-Bieb. (=J. communis var. oblonga), J. badia H. Gay (=J. oxycedrus subsp. badia), J. macrocarpa Sibth. and Sm. (=J. oxycedrus subsp. macrocarpa), J. navicularis Gand. (=J. oxycedrus subsp. transtagana), J. sibirica Brugsd. (=J. communis var. saxatilis in part), and J. lutchuensis Koidz. (= J. taxifolia var. lutchuensis).     

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.     

The telomeric GGGTTA repeats of Trypanosoma brucei contain the hypermodified base J in both strands.

We have previously shown that nuclear DNA of bloodstream from Trypanosoma brucei contains a novel base beta-glucosyl-hydroxymethyluracil, called J. Base J is enriched in minichromosome fractions but not in the minichromosome internal repeats, suggesting the association of J with telomeric DNA. To test whether J is present in the long telomeric (GGGTTA)n repeat arrays, which are 2-26 kb in T.brucei, we have purified these arrays both by hybrid selection and by isolating 2-26 kb fragments from DNA digested with multiple restriction enzymes. We find that in purified telomeric repeats approximately 13% of T is replaced by J, compared to 0.8% in total DNA, and we estimate that approximately 50% of the total J is in these repeats. Highly purified complementary strands of the repeats were obtained by alkaline CsCl equilibrium centrifugation. In the (TAACCC)n strand 14% of T was replaced by J. In the (GGGTTA)n strand approximately 36% of the second T was replaced by J; the first T was not detectably replaced. Modified bases have not been found in telomeric repeats before. How the bulky base J affects telomere function and structure in bloodstream form trypanosomes remains to be determined.     

Postembryonic development of Antygomonas incomitata (Kinorhyncha: Cyclorhagida)

Postembryonic development in the kinorhynch species Antygomonas incomitata was examined using scanning electron microscopy. The morphology of the six juvenile stages, J‐1 to J‐6, varies at numerous details, but they can also be distinguished by a few key characters. Juvenile stage 1 by its composition of only nine trunk segments; J‐2 by the combination of possessing 10 trunk segments, but no cuspidate spines on segment 9; J‐3 by the presence of cuspidate spines on segment 9, but only one pair of cuspidate spines on segment 8; J‐4 by the combination of 10 trunk segments only, but having two pairs of cuspidate spines on segment 8; J‐5 by possessing 11 trunk segments and same spine compositions as adults but is still maintaining postmarginal spiculae; J‐6 specimens closely resemble adults and are most easily identified by their reduced trunk lengths. New segments are formed in a growth zone in the anterior part of the terminal segment. The complete number of segments is reached in J‐5. Development of cuticular head and trunk structures are described through all postembryonic stages and following developmental patterns could be outlined: the mouth cone possesses outer oral styles from J‐1, but in J‐1 to J‐3, the styles alternate in size. Scalids of the introvert are added after each molt, and scalids appear earliest in the anterior rings, whereas scalids in more posterior rings are added in older postembryonic stages. The early J‐1 stage is poor in spines and sensory spots and both structures increase in number after each molt. The complete spine composition is reached in J‐4, whereas new sensory spots appear after all molts, inclusive the final one from J‐6 to adult. Sensory spots in the paraventral positions often appear as Type 3 sensory spots but are through development transformed to Type 2. This transformation happens earliest on the anterior segments. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

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。     

BOOK REVIEWS

Book reviewed in this article:
Central Pennsylvania Halloween Customs . Scientific direction by MAURICE A. MOOK, produced by D. P. DUVALL, L. P. GREENHILL, and C. CONKLIN
L'Aubrac filmed by JEAN-DOMINIQUE LAJOUX
L'Homme des Burons , filmed by J. D. LAJOUX
Le Forgeron des Hermaux , filmed by J. D. LAJOUX
Fléaux en cadence , filmed by J. D. LAJOUX
Foires d'Aubrac ou le Langage des Gestes , filmed by J. D. LAJOUX
Le Joug filmed by J. D. LAJOUX     

Genetic determinants of resistance to ectromelia (mousepox) virus-induced mortality.

Resistance to ectromelia (mousepox) virus-induced mortality was examined in crosses between susceptible DBA/2J, A/J, and BALB/cByJ mice and resistant C57BL/6J and AKR/J mice. Depending on the cross, resistance to mousepox virus was shown to be determined by one or more independently assorting autosomal loci with dominant alleles for resistance in AKR/J and C57BL/6J mice and recessive alleles in A/J, BALB/cByJ, and DBA/2J mice. A sexual dimorphism in resistance to disease was also observed.     

BOOK REVIEWS

Book reviewed in this article:
TASMANIAN FRESHWATER FISHES. By Wayne Fulton.
ADVANCES IN MARINE BIOLOGY, Volume 26. Edited by J. H. S. Blaxter and A. J. Southward.
THE SEAFOOD INDUSTRY. Edited by Roy E. Martin and Georqe J. Flick.
ADVANCES IN MARINE BIOLOGY, Volume 27. Edited by J. H. S. Blaxter and A. J. Southward.     

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.     

J chain in Rana catesbeiana high molecular weight Ig

A polypeptide homologous to human and mouse J chain has been identified in the high molecular weight (HMW) Ig of the bullfrog, Rana catesbeiana. In previous studies, we had detected a component that was similar in size to mammalian J chains and that, relative to L chains, migrated rapidly to the anode in alkaline-urea PAGE; however, its mobility was less than that of mammalian J chains. We now demonstrate that this component is covalently linked to the H chain of R. catesbeiana HMW Ig. All of the disulfide bridges of this polypeptide, like those of human and mouse J chain, can be cleaved by reducing agents even in the absence of denaturing solvents. The putative frog J chain was isolated by a procedure that did not require preliminary purification of the HMW Ig. The chain differed in amino acid composition from L chains but resembled J chains from several other species. Tryptic peptides were isolated and sequenced. Except for a single heptapeptide, the peptides could be aligned by virtue of their similarity to segments of human and mouse J chain. Of the 116 residues that were placed, 55 were identical with residues in human J chain and 60 with residues in mouse J chain. The six cysteine residues identified in the frog J chain are at the same positions as six of the eight cysteines in the human and mouse J chains. The results indicate significant conservation in structure between amphibian and mammalian Ig J chains.