{"title":"Electron microscopy of the novel barley yellow streak mosaic virus","authors":"Nancy L. Robertson, Thomas W. C","doi":"10.1016/0889-1605(89)90051-7","DOIUrl":"10.1016/0889-1605(89)90051-7","url":null,"abstract":"<div><p>Unique particles of barley yellow streak mosaic virus (BYSMV) were detected in diseased barley, wheat, and several species of grass. They appeared to be about 64 nm in width and from 127 nm to an astonishing 4000 nm in length. Individual particles were circular in transverse section. The outermost layer of each particle seemed to be a membrane-like envelope. The internal structure of many particles was bead-like. Some particles had centers that were translucent. The BYSMV particles were distributed throughout the leaf, sheath, root, and own organs of barley. Virus particles were present in all cell types of the epidermis, mesophyll, phloem, and xylem. However, mesophyll cells contained the greatest number of particles. Most BYSMV particles occurred in large clusters of quasi-parallel arrays. Both individual and groups of particles were located within the cavities of ER elements. Ribosomes were attached to some outer surfaces of the ER bounding membrane. BYSMV particles are unique because they do not resemble any in presently classified groups or families of plant viruses: they are, however, similar to those of some unclassified viruses that infect insects.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 2","pages":"Pages 139-146"},"PeriodicalIF":0.0,"publicationDate":"1989-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90051-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13777751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hendrica A. Akster , Henk L.M. Granzier , Bruno Focant
{"title":"Differences in I band structure, sarcomere extensibility, and electrophoresis of titin between two muscle fiber types of the perch (Perca fluviatilis L.)","authors":"Hendrica A. Akster , Henk L.M. Granzier , Bruno Focant","doi":"10.1016/0889-1605(89)90048-7","DOIUrl":"10.1016/0889-1605(89)90048-7","url":null,"abstract":"<div><p>I bands of perch muscle contain crosslinks that interconnect the thin filaments as well as the connecting filaments and link them to the membrane systems and to other intermyofibrillar material. In shortened sarcomeres cross connections seem to pile up in the I band and at the A/I band junction. Sarcomeres of red fibers, which in another study are reported to have steep passive stress-strain curves, were pulled apart when they were stretched by about 40% of their slack length. Sarcomeres of white fibers could be stretched by almost 100% and still display filament alignment. Sarcomeres of the red fibers also differed from those of white fibers in the distance over which connecting filaments could be discerned, the presence of an extra transverse filament in their NI lines, the electrophoretic mobility of titin, and the titin/actin ratio.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 2","pages":"Pages 109-121"},"PeriodicalIF":0.0,"publicationDate":"1989-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90048-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53919266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthias Aivirein , Roland Dürr , Hanspeter Winkler , Giorgio Travaglini , Roger Wepf , Heinz Gross
{"title":"STM of freeze-dried and PtIrC-coated bacteriophage T4 polyheads","authors":"Matthias Aivirein , Roland Dürr , Hanspeter Winkler , Giorgio Travaglini , Roger Wepf , Heinz Gross","doi":"10.1016/0889-1605(89)90054-2","DOIUrl":"10.1016/0889-1605(89)90054-2","url":null,"abstract":"<div><p>STM imaging was carried out on the outer surface of bacteriophage T4 type III polyheads, after freeze-drying and coating with a thin conducting film. By taking advantage of the high resolution power of the STM especially in the <em>z</em>-direction (i.e., perpendicular to the support), an apparent surface topography of only about 1 nm height was resolved. The average capsomere morphology was determined by correlation averaging. Because of the high signal-to-noise ratio of the tunneling data, only a few unit cells were needed to reveal a stable average. Both the topology as well as the absolute height of the polyheads have been reproduced in several experiments. The influence of the tip geometry on the STM topographs is discussed.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 2","pages":"Pages 170-177"},"PeriodicalIF":0.0,"publicationDate":"1989-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90054-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53919433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Cejka, A.Ghiretti Magaldi , G. Tognon , G. Zanotti , W. Baumeister
{"title":"The molecular architecture of extracellular hemoglobin of Eophila tellinii","authors":"Z. Cejka, A.Ghiretti Magaldi , G. Tognon , G. Zanotti , W. Baumeister","doi":"10.1016/0889-1605(89)90035-9","DOIUrl":"10.1016/0889-1605(89)90035-9","url":null,"abstract":"<div><p>The molecular shape of the extracellular hemoglobin of the annelid worm <em>Eophila tellinii</em> was investigated by electron microscopy of negatively stained single molecules and of two-dimensional crystalline arrays. While the single molecules show the characteristic double hexagons, approx 28 nm in diameter and 19 nm in height, the molecules in the crystals are only 7–8 nm in height according to the 3D reconstruction. This is attributed to a dissociation of the hemoglobin complex; we present evidence that dissociation may proceed to the level of the main subunit from which half-molecules are reassembled. 3D reconstructions of two different crystal forms yield almost identical results and provide some information about the mass distribution within the main subunit. The presence or absence of the “central subunit” is tentatively interpreted in terms of a gross conformational change which entails a redistribution of mass also in the main subunit.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 71-81"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90035-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53919166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ontogenetical changes in adipose tissue of the cat: Convertible adipose tissue","authors":"Dragutin Lončar , Björn A. Afzelius","doi":"10.1016/0889-1605(89)90028-1","DOIUrl":"10.1016/0889-1605(89)90028-1","url":null,"abstract":"<div><p>The ultrastructural characteristics of the inguinal, interscapular, and perirenal adipose tissue in kittens and cats were studied. There were no qualitative differences among adipocytes in the three anatomical areas. The only recorded difference was in the amount of lipids stored in the adipocytes in younger stages. Immediately after birth lipids occupied 25% of the volume in the inguinal area, 15% in interscapular fat tissue, and 10% in perirenal fat tissue. At this stage the adipose tissue morphologically resembled brown adipose tissue (BAT) of rodents. Two weeks after birth, lipids accumulated and adipocytes in the inguinal area became unilocular and appeared similar to white adipose tissue (WAT). A similar transition occurred approx 25 days after birth in interscapular fat and approx 6 weeks after birth in the perirenal area. No morphological signs of any cell degradation or destruction, nor any increased activity of preadipocytes, were seen during this conversion from BAT-like to WAT-like adipose tissue. The conversion of the adipose tissue was correlated with a decrease in vascularization and innervation, a loss of intercellular connections, and a changed mitochondrial population. Mitochondria in multilocular adipocytes resembled those in typical BAT which contain uncoupling protein (“UC-mitochondria”). After conversion to unilocular adipocytes the amount of mitochondria was halved, their cristae even more reduced, and their appearance was of a WAT-type (UCP-lacking mitochondria, which are coupled under physiological conditions; “C-mitochondria”). Since this category of adipose tissue differs from both typical brown and white adipose tissue, the name “convertible adipose tissue” (CAT) is proposed. Apparently adipose tissue from comparatively large mammals is of this convertible type.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 9-23"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90028-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13762277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Common sense in electron microscopy about osmium fixation","authors":"Fritiof S. Sjöstrand","doi":"10.1016/0889-1605(89)90027-X","DOIUrl":"10.1016/0889-1605(89)90027-X","url":null,"abstract":"","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90027-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53918841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robert J. Edwards , Margaret A. Goldstein , John P. Schroeter , Ronald L. Sass
{"title":"The Z-band lattice in skeletal muscle in rigor","authors":"Robert J. Edwards , Margaret A. Goldstein , John P. Schroeter , Ronald L. Sass","doi":"10.1016/0889-1605(89)90033-5","DOIUrl":"10.1016/0889-1605(89)90033-5","url":null,"abstract":"<div><p>Previous work with tetanized and relaxed muscle has shown a correlation between active tension and the structure of the Z-band. This suggests that there is a correlation between the cross-bridge binding in the A-band and the structure of the Z-band. Using electron microscopy and optical diffraction we have examined this correlation in glycerinated muscle in rigor and in unstimulated intact muscle. We have found that the Z-bands of muscles in rigor always show the basketweave form, while those of the unstimulated muscles always show the small square form. The basketweave form found in rigor muscles is similar in form and dimension to that found in tetanized muscle. Thus it appears that the small square form of the Z-band is found in physiological states with little cross-bridge binding and the basketweave form is found in states with a high degree of cross-bridge binding.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 59-65"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90033-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13762275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A mechanism for spatial brightness contrast enhancement and a basis for the duplicity of vision","authors":"Fritiof S. Sjöstrand","doi":"10.1016/0889-1605(89)90030-X","DOIUrl":"10.1016/0889-1605(89)90030-X","url":null,"abstract":"<div><p>Cones are connected to bipolar cells connected to rods by processes extending laterally from the cone terminals (<span>Sjöstrand, 1958</span>). The cone connections have been studied further in the rabbit retina. Structurally these connections are typical synaptic connections. It can be deduced that these connections must affect the on responses of bipolar cells connected to rods in such a way that spatial brightness contrast is enhanced. The connections raise the threshold for rod vision and slow down the changes in the membrane potential of on-bipolar cells. These effects offer an explanation for the duplicity of vision.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 39-46"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90030-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13762274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Morphological modifications in stored heterospermatozoa of Oxyloma elegans (Pulmonata: Stylommatophora)","authors":"M.G. Selmi, E. Bigliardi, F. Giusti","doi":"10.1016/0889-1605(89)90036-0","DOIUrl":"10.1016/0889-1605(89)90036-0","url":null,"abstract":"<div><p>The authors describe a peculiar feature of the sperm of <em>Oxyloma elegans</em> (Pulmonata: Stylommatophora) which consists in a paracrystalline body encircling the apical portion of the nucleus. This body has been seen to vanish when spermatozoa are stored in the seminal receptacles after copulation. The meaning of this phenomenon and its possible relationship to capacitation are discussed.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 82-86"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90036-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53919233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sorghum chlorotic spot virus binds to potyvirus cylindrical inclusions in tobacco leaf cells","authors":"W.G. Langenberg , S.A. Lommel , D.E. Purcifull","doi":"10.1016/0889-1605(89)90031-1","DOIUrl":"10.1016/0889-1605(89)90031-1","url":null,"abstract":"<div><p><em>Nicotiana benthamiana</em> can be doubly infected with either potato virus Y or tobacco etch virus and sorghum chlorotic spot virus (SCSV). Immunogold labeling showed that cylindrical inclusions of either potyvirus bind virions of the unrelated rod-shaped furovirus SCSV. Not all cells in doubly infected <em>N. benthamiana</em> plants contained both viruses. In cells infected by the potyviruses but not by SCSV, cylindrical inclusions did not label with the antiserum to SCSV. Numbers of cells infected with SCSV did not increase in doubly infected plants compared to those in plants infected with SCSV alone. Systemic infection of <em>N. benthamiana</em> by either potyvirus was not prevented by SCSV infections. This provides further evidence that unrelated rod-shaped viruses can bind to potyvirus cylindrical inclusion bodies, and that this phenomenon is not limited to graminaceous hosts.</p></div>","PeriodicalId":77743,"journal":{"name":"Journal of ultrastructure and molecular structure research","volume":"102 1","pages":"Pages 47-52"},"PeriodicalIF":0.0,"publicationDate":"1989-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0889-1605(89)90031-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53918998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}