Identification and distribution of profilin in tomato (Lycopersicon esculentum Mill.)

Profilin is a G-actin monomer-binding protein which has been shown to participate in actin-based tipgrowth of animal cells. The abundance of profilin in pollen and its occurrence in several vegetable foods raises the question of the role of profilin in plants. First, its distribution throughout various parts of the plant needs to be determined. This paper describes observations on the presence of profilin in the tomato plant (Lycopersicon esculentum Mill.). The distribution of profilin in flower buds, stems, leaves, roots, and fruits of tomato was determined by immunoblotting and by tissue printing, showing that profilin is present in most if not all parts of the tomato plant.We gratefully acknowledge the help provided by Dr. A.T. Jagendorf and the donation of tomato seeds and maize pollen by N. Eanetta and Dr. M. Smith, respectively. The use of Dr. R. Wayne's SZH ILLD dissecting microscope is gratefully acknowledged. This work was aided by helpful discussions with C.S. Combs, Dr. C.A. Conley, and Dr. J. Andersland. This work was supported by a Hatch grant and NRI Competitive Grants Program/USDA 94-37304-1046 to MVP. This material is based upon work supported under a National Science Foundation Graduate Research Fellowship to DWD.     

Lateral connections between heart muscle cells as revealed by conventional and high voltage transmission electron microscopy

Summary The lateral surfaces of heart muscle cells are interconnected by a varied and extensive network of structures that exist in addition to intercalated discs. Ultrastructural images of this network are vastly improved over those from epoxy-embedded material, particularly for low density components, through the application of a method for removing the embedding matrix from thin or thick sections that are then stereoscopically analyzed with standard or high voltage transmission electron microscopy. The connections include cables, 3–20 nm in diameter, multi-strand cables, 10–40 nm-granules, meshlike mats, and sheets, all extensively interwoven. It is suggested that intercellular connections of varying strength and distribution aid in the integration of mechanical performance of the large population of myocytes during the contractile cycle of the heart.This study was supported by a grant from NIH Biotechnology Resources through the University of Colorado High Voltage E.M. Laboratory, NIH Research Grant HL 24336, a N.Y. Heart Association Grant-in-Aid, and NIH Research Career Development Award HL 00568I thank Dr. E.H. Sonnenblick for continual aid and encouragement and Dr. R. Terry, Ms. Y. Kress, and Ms. J. Fant for use of facilities. I also thank Dr. K.R. Porter for guidance in the use of the HVEM technique, Dr. J.J. Wolosewick and Dr. M. Fotino for valuable suggestions, and Ms. J. Fleming, Mr. G. Wray, and Mr. G. Charlie of HVEM staff at Boulder. I acknowledge Dr. F. Pepe for use of facilities, Dr. R. Bloodgood for comments, and Mrs. L. Cohen-Gould, Ms. T. Downey, Mr. F. Reingold, Mrs. T. Maio, and Mrs. R. Shamoon for excellent assistance     

The reaction of the preoptic nucleus of Xenopus laevis tadpoles to osmotic stimulation

Summary The development of the preoptic nucleus of Xenopus laevis tadpoles during metamorphosis was studied and the effect of osmotic stimulation on this process investigated. The development of this region was not affected by treatment for one or more days in hypertonic media. It was found that at the end of metamorphosis the neurosecretory cells in the preoptic nucleus are localized in three regions: the rostro-dorsal, the caudo-dorsal and the ventral region. After osmotic stimulation only the neurosecretory cells of the caudo-dorsal region appeared to have reacted, as indicated by their loss of neurosecretory (PIC positive) material. It is concluded that the cells of this region may be involved in the synthesis of the posterior lobe hormones.The author thanks Prof. Dr. J. C. van de Kamer and Dr. F. C. G. van de Veerdonk for their interest and many helpful discussions, Dr. L. Boomgaart and Dr. A. P. van Overbeeke for correcting the English text and Miss C. M. G. van Bemmel for technical assistance.     

Subcellular location of the tetrapyrrole synthesis enzyme porphobilinogen deaminase in higher plants: an immunological investigation

A recombinant plasmid, pArab8, harbouring the cDNA encoding the mature form of the tetrapyrrole synthesis enzyme porphobilinogen deaminase (EC 4.3.1.8; also known as hydroxymethylbilane synthase) from Arabidopsis thaliana (L.) Heynh. has been constructed, and used to transform Escherichia coli. The porphobilinogen deaminase protein from Arabidopsis was overexpressed in this strain, and purified to homogeneity (3000-fold) with a yield of 20%. Antibodies were raised against the purified plant enzyme, and used in Western blot analysis, immunoprecipitation of enzyme activity and immuno-gold electron microscopy. The results indicate that the enzyme is confined to plastids in both leaves and roots. The implications of this finding for plant tetrapyrrole synthesis are discussed.Abbreviations DEAE diethylaminoethyl - FPLC fast protein liquid chromatography - PBG porphobilinogen This work was supported by Science and Engineering Research Council (SERC) and Agricultural and Food Research Council (AFRC) grants to P.M.J. and an AFRC grant to A.G.S. The protein sequencing was carried out by Mr Lawrence Hunt of the SERC MRI Protein Sequencing Unit (Director Dr M.G. Gore) at Southampton University. We acknowledge the Wellcome Foundation for financial support of the Protein and Nucleic Acid Chemistry Facility at the University of Cambridge, where the oligonucleotide primers were synthesised.     

Interaction of vesicular arbuscular mycorrhiza with root knot nematodes in tomato

Summary The interaction between the VA mycorrhizal fungus,Glomus fasciculatus and the root-knot nematodes,Meloidogyne incognita andM. javanica, and their effects on the growth and phosphorus nutrition of tomato was studied in a red sandy loam soil of pH 6.0. Inoculation of tomato roots with root-knot nematodes enhanced infection and spore production byG. fasciculatus. Inoculation of tomato plants withG. fasciculatus significantly reduced the number and size of the root-knot galls produced byM. incognita andM. javanica. Inoculation withG. fasciculatus although improved plant growth and its total phosphorus content compared to the uninoculated plants, the difference were not statistically significant.     

Staphylococcus aureus alpha-toxin-induced pores: Channel-like behavior in lipid bilayers and patch clamped cells

The conductance of pores induced by Staphylococcus aureus -toxin in Lettre cells has been compared to that in bilayers composed of synthetic lipids or Lettre cell membrane constituents. Previously described characteristics of toxin-induced conductance changes in lipid bilayers, namely rectification, voltage-dependent closure, and closure at low pH or in the presence of divalent cations (Menestrina, 1986) are displayed also in bilayers prepared from Lettre cell membranes and in patch clamped Lettre cells. It is concluded that endogenous proteins do not affect the properties of -toxininduced channels significantly and that the relative lack of ion channels in Lettre cells makes them ideal for studies of pore-forming toxins by the patch clamp technique.Dr. Sviderskaya is on leave of absence from the Physiology Institute, University of St. Petersburg, RussiaWe are grateful to Dr. J.P. Arbuthnott and Dr. K. Hungerer for gifts of S. aureus -toxin, to Dr. T.B. Bolton for collaboration with patch clamped cells and to Dr. J.M. Graham for help with the preparation of Lettre cell plasma membranes. This study was supported by the Cell Surface Research Fund, Medical Research Council, Science and Engineering Research Council, UNESCO (Molecular and Cell Biology Network) and The Wellcome Trust.     

Nuclear membranous whorls

Summary Membranous whorls have been seen in the nuclei of peritoneal and testicular cells which had been subjected to various experimental manoeuvres. It seems likely that this is an early manifestation of cell degeneration which is demonstrated readily only by glutaraldehyde fixation, and to that extent can be regarded as a glutaraldehyde artifact. Acknowledgements. This work was supported by grants from the Medical Research Council, and the University of Sheffield Tuberculosis Research Fund, and by a grant to the Department from Unilever Ltd.I am grateful to Professor R. Barer for his advice and criticism, to Dr. G. A. Meek for guidance on electron microscopy, to Dr. E. J. Clegg for permission to use material from joint experiments. Technical and photographic assistance was provided by Messrs. P. GarLick and L. Murgatroyd and by Miss M. Tune.     

Interactions between Limonium vulgare and Plantago maritima in the Plantagini-Limonietum on the Boschplaat,Terschelling, The Netherlands

Limonium vulgare and Plantago maritima are growing together over large areas and in varying proportions on the Boschplaat salt marsh. The question is how both species interact and which environmental factors play a role in those interactions.There are indications of different measures of niche differentiation in the Plantagini-Limonietum association related to differences in flooding frequency and substrate. Interactions between both species are described according to three models (related to de Wit's competition model). Mechanisms that may cause niche differentiation are: differences in growth rhythm, in salt tolerance, in rooting depth, in preference to types of substrate, in morphology, in mycorrhizae and diseases.On a small scale (spatial heterogeneity in the marsh and variation in subsequent seasons) Limonium can achieve a bigger portion in the vegetation by occupying open sites faster than Plantago. On a larger scale (the whole marsh, decades) the impossibility of Plantago to germinate and rejuvenate after sedimentation of silt and salinisation of the soil is the determining factor causing an overall decrease of this species (compared with Limonium) and increase of Limonium.The life cycle of both species, criteria for scale in space and time, and the question whether the Plantagini-Limonietum should be considered a syntaxon, are discussed.Nomenclature follows Heukels-van Ooststroom (1977).I like to thank Dr. P. Ketner and Dr. C. J. T. Spitters for their accompaniment and their ideas, so that I was aware of the wood (Boschplaat) for the trees. I also like to thank Drs. A. J. M. Roozen and Prof. Dr. E. van der Maarel for their discussions about this subject on many occasions. Finally I would like to thank Dr. W. G. Beeftink for his ideas and support and Ron Don, Wim van Hooff, Sjef Jansen, Alex Jonker, Annemiek Demon, Wim Heijligers, Marlie Becks and Frans Wilms for providing the basic concept (the Plantagini-Limonietum) and for their help.     

Introduction to General and Generalized Linear Models by MADSEN,H. and TYREGOD,P.

Introduction to General and Generalized Linear Models (H. Madsen and P. Tyregod) Clarice Demétrio Sample Sizes for Clinical Trials (S. A. Julious) Janet Wittes Learning and Inference in Computational Systems Biology. (N. D. Lawrence, M. Girolami, M. Rattray and G. Sanguinetti) Ernst Wit Brief Reports by the Editor Applied Probability, 2nd edition. (K. Lange) Regression Estimators: A Comparative Study, 2nd edition. (M. H. J. Gruber) Common Statistical Methods for Clinical Research with SAS Examples, 3rd edition. (G. A. Walker and J. Shostak)     

The rostral pars distalis of the pituitary gland of the freshwater and marine alewife (Alosa pseudoharengus)

Summary In the alewife the orohypophyseal duct, a remnant of Rathke's pouch, persists in adults as a tube passing from the rostral pars distalis to the pharyngeal region. Its lumen is not open to the buccal cavity. The prolactin cells are situated around the bifurcations of this duct in the rostral pars distalis. Contents from prolactin cells, such as granules, nuclei, mitochondria and Golgi structures were found in these bifurcations. These contents were indistinguishable from those of intact prolactin cells. Evidence of actual release into the duct was often noted. At the presumptive point of release, the cells lining the lumen separate and the contents, probably of an entire prolactin cell, are extruded. The cilia usually found at the point of extrusion arise from prolactin cells. The prolactin cells of freshwater fish were more heavily granulated than those from a marine environment. Prolactin cells of fish entering freshwater streams were not heavily granulated but showed evidence of increased activity. Granule size was not affected by salinity. The ACTH cells are arranged in bands along branches of the neurohypophysis in the rostral pars distalis. No differences in ACTH cells from fish of different salinities were noted.We would like to thank Mr. D. D. Zumwalt of the John G. Shedd Aquarium in Chicago, Dr. E. D. Warner, Mr. R. L. Flayter, Dr. J. G. Stanley of the University of Wisconsin, Milwaukee, Mr. L. Wells of the U. S. Fish and Wildlife Service, Great Lakes Fisheries Laboratory, Ann Arbor, and Mr. L. N. Flagg of the Department of Sea and Shore Fisheries, Augusta, Maine, for their assistance in obtaining the fish used in this study. Dr. T. N. Tahmisian and Mr. G. T. Chubb of Argonne National Laboratories, and Dr. L. M. Srivastava and Dr. V. Bourne of Simon Fraser University, Canada, kindly made electron microscope facilities available. Finally, we wish to thank Mr. W. Goossens and Mr. D. J. DeJong for valuable assistance. This project was supported by a grant from the National Marine Fisheries Service.     

The gonadotropic cells in the adenohypophysis of the blind mexican cave fish,Anoptichthys jordani

Summary The development and activity of the basophils in the meso-adenohypophysis of Anopthichthys jordani were studied in relation to the maturation of the gonads. In addition, pituitaries and ovaries of post-spawning females were studied during a period 0–11 days subsequent to spawning. The large and mainly PAS-positive basophilic cells in the meso-adenohypophysis were the only cell type that showed a correlation with the development and maturation of the ovaries and testes. These cells were subjected to a partial or complete degranulation in females following oviposition, when yolk formation in the ovary was at a maximum. It is concluded that the large PAS-positive basophils in the mesoadenohypophysis have a gonadotropic function and that only one gonadotropic cell type is present in the adenohypophysis of Anoptichthys jordani.This study was partly supported by a grant from the Netherlands Organization for the Advancement of Pure Research (Z.W.O.).I wish to express my gratitude to Prof. Dr. P. G. W. J. van Oordt for his active interest and constructive suggestions. Mr. R. van den Hurk and Miss Tjitske van Soelen provided valuable assistence in the course of the experiments. Mr. H. van Kooten made the photographs. Special thanks are due also to Mr. M. J. van Oosterum and Mr. J. Rowaan; without their capable and constant help it would have been hardly possible to obtain such satisfactory spawning results.     

Isolation and identification of orsellinic acid and penicillic acid produced byPenicillium fennelliae Stolk

Fifteen days-old surface cultures ofPenicillium fennelliae Stolk grown on a modified Czapek medium were analyzed for the production of metabolites. The presence of orsellinic acid, orcinol and penicillic acid was proved by means of chromatographic and physicochemical methods.The author is indebted to Mr. J. A. Weber and Dr. M. J. A. de Bie of the Laboratory of Organic Chemistry, University of Utrecht for measuring the UV and 60 Mc NMR spectra and to Mrs. G.E.E. Snijders-Woldringh, Miss L. Veldstra and Miss H. G. M. Stolwijk of the Institute for Organic Chemistry TNO, Utrecht for running the IR and 100 Mc NMR spectra and for performing the microanalysis.The mass spectra were determined by Mr. W. Heerma of the Analytical Laboratory, University of Utrecht, whom we wish to thank for helpful discussions on the interpretation of the results.The skillful technical assistance of Miss M. van Rietschote is gratefully acknowledged.     

Nematicidal effect of an Amaranthus hypochondriacus L. cystatin (AhCPI) on the root-knot nematode Meloidogyne incognita (Kofoid and White) Chitwood

The root-knot nematode Meloidogyne incognita is one of the most damaging plant parasitic nematodes in the world. In this study, the effect of cystatin from Amaranthus hypochondriacus (AhCPI) as a potential control agent for M. incognita was explored. In vitro bioassays demonstrated that AhCPI affects the growth and development of eggs and the infectivity of juveniles (J2) of M. incognita, such as mortality and slower development, showing characteristic tissue damage. Mortality levels were quantified by Probit analysis, estimating LC₅₀s of 1.4 mg/mL for eggs and 0.028 mg/mL for J2. In planta bioassays showed that infected tomato seedlings treated with 0.056 mg/mL of AhCPI showed a 60% reduction in the number of galls, as compared with untreated J2-inoculated seedlings. Under greenhouse conditions, three applications of 10 mL of AhCPI (1.4 mg/mL) in the soil around the stem of M. incognita-infected tomato plants, reduced the number of galls by 93 ± 8%, as compared to the control M. incognita-infected plants. The application of AhCPI to the infected plants increased the yield (10.7%) of harvested tomato fruits, as compared to infected plants. These results show the potential of AhCPI for the control of M. incognita in tomato plants.     

Evidence for corticotropin releasing factor (CRF) synthesis in the preoptic nucleus of Xenopus laevis tadpoles

Summary For the study of the hypothalamo-hypophysial system of Xenopus laevis tadpoles, hypothalamic lesions were made by means of the electrocoagulation technique. Lesioning of the ventral region of the preoptic nucleus resulted in a decrease of the number of ACTH cells in the pars distalis of the pituitary gland and in a diminution of the PAS-positive reaction of these cells. In addition, regeneration of the neurosecretory cells of the ventral region of the preoptic nucleus observed 6 weeks after lesioning was accompanied by the reappearance of normal PAS-positive ACTH cells in the pars distalis. It is suggested that the neurosecretory cells of the ventral region of the preoptic nucleus of Xenopus laevis tadpoles are related to the ACTH synthesizing cells, probably by producing CRF.Dedicated to Prof. Dr. med. W. Bargmann on the occasion of his 70th birthdayThe authors thank Prof. Dr. J.C. van de Kamer for his interest, Prof. Dr. P.G.W.J. van Oordt for his many helpful comments, and Messrs. H. van Kooten, E. van der Vlist, J.J. van der Vlis and M.C.A. van Pinxteren for preparing the illustrations     

Polygalacturonase expression during leaf abscission of normal and transgenic tomato plants

Polygalacturonase (PG, EC 3.2.1.15), an enzyme commonly found in ripening fruit, has also been shown to be associated with abscission. A zone-specific rise in PG activity accompanies the abscission of both leaves and flowers of tomato (Lycopersicon esculentum Mill.) plants. Studies of transgenic plants expressing an antisense RNA for fruit PG indicate that although the enzyme activity in transgenic fruit is < 1 % of that in untransformed fruit, the PG activity in the leaf abscission zone increases during separation to a similar value to that in untransformed plants. The timing and rate of leaf abscission in transgenic plants are unaffected by the introduction of the antisense gene. A polyclonal antibody raised against tomato fruit PG does not recognise the leaf abscission protein. Furthermore a complementary DNA (cDNA) clone (pTOM6), which has been demonstrated to code for fruit PG, does not hybridise to mRNA isolated from the abscission-zone region of tomato leaves. These results indicate that the PG protein in abscission zones of tomato is different from that in the fruit, and that the gene coding for this protein may also be different.Abbreviation PG polygalacturonase The authors of this paper are grateful to David Jackson of the John Innes Institute, Norwich, UK for his assistance with the in-situ hybridisation work. This research was supported by an Agricultural and Food Research Council Post-Doctoral award to J.E.T., and by a grant to D.G. from the Science and Engineering Research Council Biotechnology Directorate in association with ICI seeds. The work was carried out under Ministry of Agriculture, Food and Fisheries licences.     

Assessment of some genetic non-MHC differences with GVHR-induced anti-listeria activity of macrophages

Parental cells A injected into (A × B)F₁ heterozygotes induce a graftversus-host reaction (GVHR) which induces systemic activation of anti-Listeria-bactericidal capacity of host macrophages. When donor lymphocytes differ from parent A with respect to various non-H-2 genetic markers, they may or may not be able to induce a GVHR. Some, but not all, known and some unknown non-H-2 differences can be assessed by this method within nine to 12 days. The method is described and some of the following non-H-2 differences are shown to influence GVHR-induced macrophage activation: male H-Y antigen, H-3 or H-4 (but not H-1 or H-9), and as yet underlined differences that apparently exist between mouse substrains of the same or similar designation, but obtained from different breeding establishments.Abbreviations used in this paper: H histocompatibility - GVHR graft-versus-host reaction - MHC major histocompatibility gene complex - SCRF Scripps Clinic and Research Foundation - J Jackson Laboratory - St Strong Foundation - Cum Cumberland View Farm - Ola Olac - Gh Dr. G. Haughton, Chapel Hill - Sal Dr. M. Cohn, La Jolla.