α-and β-Glycosidases in maize roots

Four glycosidases were analyzed in 10 mm apical segments prepared from growing roots (15 mm) of Zea mays L. The pH optima were found to be 5.8 for -glucosidase, 4.4 for -galactosidase, 6.4 for -glucosidase and 6.0 for -galactosidase. The -glucosidase showed 4-fold higher activity than the -galactosidase. The distribution of the -glucosidase activity was signifcantly different from that of the -galactosidase, -glucosidase and -galactosidase.Abbreviations -Glu -glucosidase - -Gal -galactosidase - -Glu -glucosidase - -Gal -galactosidase     

Mutation induction by γ and X-ray irradiation in tissue cultured lotus

Mutations of tissue cultured lotus were induced by treating plantlets with either acute -rays at doses of 0, 2, 3, 4, 5 or 6 krad or X-rays at doses of 0, 1, 2, 3, 4 or 5 krad. The 2-krad dose of either - or X-ray treatments resulted in a 50% survival rate. The use of - and X-rays to induce mutation in lotus resulted in 21 altered characteristics. Mutants from 1- and 2-krad of either or X-rays had long secondary roots and numerous adventitious roots. These mutants also exhibited good shoot growth and healthy rhizome development. Most plants treated with 3–5 krad of either - or X-rays exhibited abnormal characteristics including vitrification, chlorosis, deformed petioles and in addition had inhibited growth of lateral buds, secondary roots and rhizomes. All plants treated with 6 krad of -rays died within 4 weeks. Control plants had stoma lengths of 2.56 m and cytological analysis of the root tips confirmed the diploid chromosome number of 16. Two groups of aneuploid cells were achieved using irradiation at doses of 3 and 4 krad of either - or X-ray. Chromosome numbers were 2n=18 and 20 with associated stoma lengths of 3.43 and 4.34 m, respectively. Abnormal stomata (cyclocytic and deformity) were observed in plants treated with 4 krad of -ray.     

Ultrastructure of four types of striated muscle fibers in the atlantic hagfish (Myxine glutinosa,L.)

Summary Four types of striated muscle fibers with distinctive ultrastructure were defined in the Atlantic hagfish (Myxine glutinosa, L.): white, intermediate, and red fibers of m. parietalis, and red fibers of m. craniovelaris.White fibers are thick, contain very few mitochondria and fat vacuoles, and possess distinct and separate myofibrils with thin Z-disks and distinct M-lines. Intermediate fibers are thinner, possess largely similar myofibrils that often are even better separated due to a higher content of fat vacuoles and especially mitochondria and glycogen granules. Red fibers of m. parietalis contain large amounts of mitochondria, fat vacuoles, and glycogen granules. Their myofibrils possess M-lines, and although branching more, the myofibrils of red fibers conform with a Fibrillenstruktur pattern like those of white and intermediate fibers. Red fibers of m. craniovelaris are very thin, possess many smaller fat vacuoles, and large amounts of mitochondria and glycogen granules. The myofibrils are significantly thinner than in m. parietalis fibers, run as quite independent well separated units, possess thicker Z-disks, and lack M-lines. Large amounts of myosatellite cells are associated with these red fibers.Triads are located near A/I-junctions in all four fiber types and occur irregularly, the density of triads being different in the various fiber types.We are indebted to Dr. Finn Walvig, Biological Station, University of Oslo, Drøbak, for supply of hagfishes, and we also wish to thank Dr. Jan K. S. Jansen, Institute of Physiology, University of Oslo, for valuable suggestions during this study.     

Variability in the 11S globulin fraction of seed storage proteins ofHelianthus (Asteraceae)

The seed storage globulins from sixHelianthus and four hybrids were studied using mono and bidimensional gel SDS electrophoresis (+ 2 mercaptoethanol). The polypeptide composition of each subunit was determined. Different pairs are specifically expressed according to the species studied. Three typical patterns were discriminated. All the studied species exhibit five subunits: two of them are expressed in all the species (₁₁ and ₂₂). The subunit corresponding to the ₁₁ pair is present inH. petiolaris and in the three populations ofH. annuus studied. The _2b2 pair is common toH. annuus andH. argophyllus. H. petiolaris presents two specific _2a2 and ₄₄ pairs andH. annuus a specific ₃₃ pair. InH. argophyllus _{11 33} or ₄₄ are never observed but are replaced by ₁₃ and ₃₁ pairs. Some globulins, poorly represented, are of forms but present chains of higher molecular weights (in the range 54–56 kDa). Expressing variations in the banding patterns between these species by the use of a similarity index reveals complete identity between the three populations ofH. annuus. Identity between the twoH. petiolaris studied is also observed.H. annuus andH. argophyllus appear to be closer to each other thanH. petiolaris concerning the seed storage globulins.     

<Emphasis Type="Italic">In vitro</Emphasis> screening of sugarcane to evaluate smut susceptibility

Tissue-cultured plantlets of three sugarcane (Saccharum spp.) cultivars having a known field smut reaction were screened for susceptibility to Ustilago scitaminea H&P Sydow. Plantlets were inoculated with 0.5 l of a suspension of equally mixed quantities of plus and minus mating type sporidia of U. scitaminea at concentrations ranging from 1×10¹ to 1×10⁶ cells. Fungal sori (whips) were produced in cultivar N12 (intermediate) 6weeks following inoculation with 1×10⁵ mixed sporidia and thereafter in cultivar NCo310 (susceptible) but not in cultivar N19 (resistant). Sori bearing teliospores were produced up to 3months following inoculation and incubation at 26°C. No sori were produced at mixed sporidial concentrations lower than 1×10⁵cells. The in vitro soral production in cultivars N19, N12 and NCo310 was 0, 27.5 and 47.5% respectively. Plantlets inoculated with 1×105sporidia of only one mating-type did not produce sori in any of the three cultivars tested. Blind scoring of an unknown sugarcane cultivar by this method corresponded exactly with its field smut rating.     

Effects of supplied cinnamic acids and biosynthetic intermediates on the anthocyanins accumulated by wild carrot suspension cultures

Anthocyanins isolated and characterized from the wild carrot suspension cultures used here were 3-O--D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D<-galactopyranosylcyanidin (1), 3-O-[-D- xylopyranosyl-(12)--D-galactopyranosyl]cyanidin (2), 3-O-(6-O-sinapoyl)--D-glucopyranosyl-(16)-[-D- xylopyranosyl-(12)-]-D-galactopyranos ylcyanidin (3), 3-O-(6-O-feruoyl)--D-glucopyranosyl-(16)-[- D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (4), 3-O-(6-O-coumaroyl)--D-glucopyranosyl-(16)- [-D-xylopyranosyl-(12)-]-D-galactopyrano sylcyanidin (5), 3-O-[6-O-(3,4,5-trimethoxycinnamoyl)]-- D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (6), 3-O-[6-O-(3,4-dime- thoxycinnamoyl)]--D-glucopyranosyl-(16)-[-D-xylopyranosyl-(12)-]-D-galactopyranosylcyanidin (7), 3-O-[(6-O-sinapoyl)--D-glucopyranosyl-(16)--D-galactopyranosyl]cyanidin (8), and 3-O-(-D-galactopyranosyl)cyanidin (9). Except when cinnamic acids were provided in the culture medium, the major anthocyanin present in the two clones examined was 2. When the naturally occurring and some non-naturally occurring cinnamic acids were provided individually in the medium, 1 and 2 were minor components and the anthocyanin acylated with the supplied cinnamic acid, namely 3, 4, 5, 6, or 7 was the major anthocyanin present in the tissue. When caffeic acid was provided the major anthocyanin in the tissue was 4, thereby suggesting that the caffeic acid was methylated before its use in anthocyanin biosynthesis. Other cinnamic acids supplied had limited effects on the anthocyanins accumulated and appeared not to result in the accumulation of new anthocyanins by the tissue. Thus the tissue can use some but not all analogues of sinapic acid to acylate anthocyanins. Additional anthocyanins were detected in extracts of the wild carrot tissue cultures using mass spectrometry (both MS/MS and HPLC/MS). The additional compounds detected have also been found in cultures of black carrot, an Afghan cultivar of Daucus carota ssp. sativa and the flowers of wild carrot giving no evidence for qualitative differences in the anthocyanins synthesized by subspecies, cell cultures from subspecies, or clones from cell cultures. There are major differences in the amounts of individual anthocyanins found in cultures from different subspecies and in different clones from cell cultures. Here anthocyanins without acyl groups were usually found in the tissues and their accumulation is discussed. On the basis of the structures of the isolated anthocyanins, a likely pathway from cyanidin to the accumulated anthocyanins is proposed and discussed.Abbreviations Sin sinapoyl - Fer feruoyl - 4-Coum. 4-coumaroyl - 3,4-MeO₂Cin 3,4-dimethoxyeinnamoyl - 3,4,5-MeO₃Cin 3,4,5-trimethoxycinnamoyl - Cya cyanidin     

Helical kink and channel behaviour: a comparative study with the peptaibols alamethicin,trichotoxin and antiamoebin

Kinks or bends introduced in peptides and proteins by helical distorter residues such as proline, other imino acids and glycine, especially when these are in close proximity in the sequence, are increasingly recognized as playing an essential role in the gating of channel-forming peptides as well as of physiological ion channels. Peptaibols are useful simple models for the much more complex biological ion channels, especially voltage-gated ones. In this short review, we compare the monomeric structures of three selected peptaibols (alamethicin, trichotoxin and antiamoebin) that widely differ with regards their near-central kink angles and dipolar moment orientations. These structural features are then shown to be correlated to the different patterns of channel activity, both at the macroscopic and single-channel levels of investigation.Presented at the British Biophysical Society–Société Française de Biophysique joint meeting Ion channels: from Biophysics to disorders, held in May 2003, Rennes, France     

Contribution to the knowledge of the enzymatic activity of yeasts of clinical interest

The determination of the enzymatic activity of the yeasts has been applied to the identification of species, specially that ofCandida albicans. In order to know its usefulness in species of clinical interest, we have tested the commercial system API ZYM (Bio Mérieux) on 500 isolated strains of different organic samples, belonging to eight genera and twenty species. All the strains showed positivity to Phosphatase alcaline, Esterase (C4), Esterase lipase (C8), Leucine arylamidase and Phosphatase acid, and negativity to Lipase (C14), Trypsin, Chymotrypsin, -galactosidase, -glucoronidase, -manosidase and -fucosidase. Fourteen enzymatic activity patterns were obtained considering the substrates with variable results for the whole of the strains: Valine arylamidase, Cystine arylamidase, Naphthol-AS-BI-phosphohydrolase, -galactosidase, -glucosidase, -glucosidase and N-acetyl--glucosaminidase. In the majority of the species, the enzymatic profile did not have very specific results since it is usually shared by more than one species.C. albicans is that which presents the greatest number of enzymatic variations, some of these are similar to those of other common clinical species, such asCandida krusei, Candida parapsilosis andCandida tropicalis. This system is proposed as a rapid method for identification and as an epidemiological marker of medically important yeasts.Abbreviations AGL -glucosidase - BGA -galactosidase - BGL -glucosidase - CAA Cystine arylamidase - NAG N.Acetyl--glucosaminidase - PHO Naphthol-AS-BI-phosphohydrolase - VAA Valine arylamidase     

Purification and properties ofβ-fructofuranosidase from Aspergillus japonicus

-Fructofuranosidase fromAspergillus japonicus, which produces 1-kestose (O--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) and nystose (O--d-fructofuranosyl-(21)--d-fructofuranosyl-(21)--d-fructofuranosyl -d-glucopyranoside) from sucrose, was purified to homogeneity by fractionation with calcium acetate and ammonium sulphate and chromatography with DEAE-Cellulofine and Sephadex G-200. Its molecular size was estimated to be about 304,000 Da by gel filtration. The enzyme was a glycoprotein which contained about 20% (w/w) carbohydrate. Optimum pH for the enzymatic reaction was 5.5 to 6. The enzyme was stable over a wide pH range, from pH 4 to 9. Optimum reaction temperature for the enzyme was 60 to 65°C and it was stable below 60°C. The K_m value for sucrose was 0.21m. The enzyme was inhibited by metal ions, such as those of silver, lead and iron, and also byp-chloromercuribenzoate.     

Phylogenetic relationship of zeins and coixins as determined by immunological cross-reactivity and Southern blot analysis

Zeins from Zea mays L cv. Maya and coixins from Coix lacryma-jobi L. cv. Adlay were fractionated to obtain -, -, and -zein and -, -, and -coixin. The -coixins were composed of 4 polypeptide classes of 27 kDa (C1), 25 kDa (C2), 17 kDa (C4) and 15 kDa (C5) with solubility properties very similar to those of the 22 kDa and 19 kDa -zeins. Like the -zeins, the C1 and C2 -coixins corresponded to 80% of total Coix prolamins. The fraction corresponding to -coixin contained only one protein band of 22 kDa (C3). This coixin fraction has solubility properties similar to those of -zein and represents 15% of the total coixin. The -zein fraction was composed of a major 17 kDa protein band, while the -coixin fraction consisted of a mixture of - and -coixins.Polyclonal antibodies raised against C1 recognized C1 and C2 and cross-reacted strongly with the 22 kDa -zein, as did C4 and C5 antisera. The antiserum against -coixin showed strong cross-reaction with -zein. The homology between coixins and zeins was further investigated by using Southern hybridization analyses. The genomic DNA of maize and Coix were digested with several restriction enzymes and probed with cDNA clones representing 19 and 22 kDa -zeins as well as the 28 and 16 kDa -zeins. The Coix genome showed complex cross-hybridization sequences with the 22 kDa -zein cDNA, while no cross-hybridization was observed with the 19 kDa cDNA clone. The cDNA clone representing the 28 kDa -zein cross-hybridized with only one band of Coix genomic DNA, in contrast to the three bands observed in maize. This same Coix sequence also cross-hybridized with the cDNA clone representing the 16 kDa -zein. The relevance of these findings are discussed in the context of the origin of zein and coixin genes.     

Dicentric chromosomes in monolayers of human lymphocytes produced by monochromatized synchrotron radiation with photon energies from 1.83 keV to 17.4 keV

A systematic approach was used to examine the induction of dicentric chromosomes in human lymphocytes irradiated in vitro with monochromatized synchrotron radiation produced with photon energies in the range from 1.83 keV to 17.4 keV. To avoid potential confounding factors that could influence the outcome of the experiments, only blood from one individual was used. Since for the irradiation experiments with these low photon energies the local dose variations would become unacceptable, monolayers of lymphocytes attached within 3 h PHA stimulation have been used. The culture conditions ensured that the chromosome analysis could be performed exclusively in metaphases of the first cell cycle in vitro. There is a strong indication for a systematic change of the coefficient of the linear quadratic dose-response relationship from 1.83 keV (=1.26±0.28) with increasing energy up to 6.9 keV (=8.24±0.41) and a decrease with further increase of energy up to 17.4 keV (=3.83±1.72). A tendency for a systematic change of the coefficient seems to be present at energies of 6.9 keV (=8.04±0.40) and 4.8 keV (=9.48±1.57) as well as at energies of 3.10 keV (=2.99±0.51) and 1.83 keV (=0.40±0.25). These results agree in essence with the previously published large data set from Sasakis laboratory.     

On age morphological changes of males of Chydoridae (Cladocera)

Summary Young and adult males of 11 species of Chydoridae are studied, their figures being published here (fig. 1–15). The necessity is stressed to distinguish young forms of males and gynandromorphic individuals.Pleuroxus balatonicus is considered to be described from the population ofPleuroxus unicatus having under Balaton Lake conditions retarded transformation of young males into adult form, and accordingly having unusually numerous young males. \qO\qs\qn\qo\qv\qn\qy\ye \qr\ye\qz\qu\ql\Qj\qt\qa\qt\qy 11 (. 1–15). . , Pleuroxus uncinatus , Pleuroxus balatonicus.     

Further cytogenetic analyses of the Croatian triploid shallot “Ljutika” (Allium cepa var.viviparum, Alliaceae) and its comparison with the Indian triploid “Pran”

Feulgen and silver-stained karyotypes and meiosis of two triploid viviparous onion forms (Allium cepa var.viviparum), the Croatian Ljutika and the Indian Pran, were comparatively analyzed. The results of chromosome measurements show that Ljutika and Pran are karyologically not identical, although significant similarities were found in the morphology of their chromosomes. Five geographically distant clones of Ljutika showed good agreement in the number and gross morphology of the chromosomes and in the number and position of NORs and interphase nucleoli. Heterotrivalents were predominant in meiosis of Ljutika but a relatively high frequency of higher multivalents together with univalents and bivalents were also observed. The relationship between Ljutika and Pran and their possible origin are discussed.     

Production of a novel syrup containing neofructo-oligosaccharides by the cells of Penicillium citrinum

A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.     

Enzymatic basis for sialyl-Tn expression in human colon cancer cells

Sialyl-Tn antigen (SA2-6 GalNAc-Ser/Thr) is expressed as a cancer-associated antigen on the surface of cancer cells and its expression correlates with a poor prognosis in patients with colorectal and other adenocarcinomas. To understand the enzymatic basis of sialyl-Tn (STn) antigen expression, we used two clonal cell lines, LSB and LSC, derived from LS174T human colonic cancer cells. LSC cells express only the truncated carbohydrate antigen Tn (GalNAc-Ser/Thr) and sialyl-Tn on their mucin molecules, whereas LSB cells express elongated oligosaccharide chains. Both cell lines demonstrated similar activities of glycosyltransferases involved in the biosynthesis of elongated and terminal structures of complex O-glycans. However, LSC cells were unable to synthesize core 1 (Gal1-3GalNAc-) because the ubiquitous enzyme activity of UDP-Gal:GalNAc-R 3-Gal-transferase (core 1 3-Gal-transferase) was lacking. Core 1 3-Gal-transferase could not be reactivated in LSC cells by treatment with sodium butyrate or by in vivo growth of LSC cells in nude mice. In contrast, LSB cells were able to synthesize and process core 1 and core 2 (GlcNAc1-6 (Gal1-3) GalNAc-). LSC cells represent the first example of a non-hematopoietic cell line which lacks core 1 3-Gal-transferase activity. The lack of core 1 3-Gal-transferase in LSC cells explains why they are incapable of forming the common mucin O-glycan core structures and are committed to synthesizing the short Tn and STn oligosaccharides. These findings suggest that the activity of core 1 3-Gal-transferase is an important determinant of the STn phenotype of colon cancer cells.     

Subcellular localization of calcium in sporangiophores of Phycomyces blackesleeanus

The in situ localization of Ca²⁺ in stage I sporangiophores of the fungus Phycomyces blakesleeanus was achieved with the potassium pyroantimonate technique. Precipitates of calcium-antimonate were present in mitochondria, vacuoles, endoplasmic reticulum and adjacent cytoplasm, Golgi-like bodies, and nuclei but not cell walls. Material treated with the calcium chelator EGTA lacked these precipitates. The preferential localization of Ca²⁺ in mitochondria, endoplasmic reticulum and vacuoles suggests that these organelles modulate the level of this cation in sporangiophores of P. blakesleeanus.Abbreviations EGTA ethyleneglycol-bis-(-aminoethyl ether) N,N, tetraacetic acid     

Tissue culture ofKarwinskia humboldtiana—a plant producing toxins with antitumoural effects

Isolated embryos ofKarwinskia humboldtiana were cultured in vitro. The growth of embryos and development to plantlets on woody plant medium supplemented with indole-3-acetic acid 6.10^-2 mol l^–1, gibberellic acid (GA₃) 3.10^-2 mol l^–1, and 6-benzylaminopurine (BA) 2 mol l^–1 was obtained. Multiplication of shoots and rooting of excised shoots has been achieved. Callus formation on modified Murashige-Skoog medium supplemented with 1-naphthaleneacetic acid 10 mol l^–1, GA₃ 14 mol l^–1, and kinetin 5 mol l^–1 on hypocotyls, or on root cultures on medium supplemented with 2.4-dichlorophenoxyacetic acid 10 mol l^–1 and BA 10 mol l^–1 was induced.Abbreviations BA 6-benzylaminopurine - 2,4-d 2,4-dichlorophenoxyacetic acid - GA₃ gibberellic acid - IAA indole-3-acetic acid - NAA 1-naphthaleneacetic acid - TEM transmission electron microscopy     

Rapid plant regeneration of pea using thidiazuron

A simple and rapid pea regeneration procedure was developed. An average of up to 20 shoots formed from hypocotyl explants of cvs. Sugar Ann and Patriot cultured on Murashige and Skoog basal medium supplemented with 0.5 or 1.0 M thidiazuron (N-phenyl-N-1,2,3-thiadiazol-5-ylurea). Hypocotyls of Puget and Sugar Daddy did not respond. Regenerated shoots rooted rapidly when cultured on Murashige and Skoog basal medium containing either 2.0 M -naphthaleneacetic acid or 1.0–2.0 M indole-3-butyric acid. Seeds were harvested from regenerated plants after only 9–11 weeks.Abbreviations BAP 6-benzyladenine - 2,4-d 2,4-dichlorophenoxy acetic acid - GA₃ gibberellic acid - IBA indole-3-butyric acid - MS Murashige and Skoog (1962) medium - NAA -naphthaleneacetic acid - TDZ thidiazuron (N-phenyl-N-1,2,3-thiadiazol-5-ylurea)     

The spermatozoon of Oikopleura dioica Fol (Larvacea,Tunicata)

Summary The spermatozoon of Oikopleura dioica is about 30 m long, with a spherical head, about 1 m wide, a 3 m long and 1 m wide midpiece, and a 25 m long tail with a tapered end piece. The head contains a nucleus with the chromatin volume limited to about 0.1 m³. A small acrosome is found in an anterior inpocketing, and a flagellar basal body in a posterior inpocketing of the nucleus. The midpiece contains a single mitochondrion with the flagellar axoneme embedded in a groove along its medial surface. The flagellar axoneme has the typical 9 + 2 substructure, and the basal body the typical 9+0 substructure. A second centriole and special anchoring fibres are absent.     

The pancreatic islets of the teleost Scorpaena scropha

Summary The principal pancreatic islets of the teleost Scorpaena scropha are found ultrastructurally to contain four different kinds of parenchymal cells, viz. ₁-(= D), ₂-, -and agranular cells. The -cells show considerable variations in the shape of the secretory granules. A peculiar feature is that many of these granules are composed of fibrillar subunits, often in parallel arrangement. All -granules are surrounded by membranes and between the membrane and the granule core there is a moderately wide electron lucent space. The electron density of the cytoplasm in the -cells varies somewhat. The ₂-cells possess typical secretory granules with an electron dense core and a closely applied membrane. The secretory granules in the ₁-cells show also a closely applied membrane but a less dense core. Also in the -cells the electron opacity of the cytoplasm varies. The agranular cells are mainly characterized by low cytoplasmic electron density, narrow cisterns of endoplasmic reticulum and sometimes a laminated Golgi complex. Small immature secretory granules are occasionally seen in the cytoplasm of these cells. The significance of the fibrillar -granules remains obscure.This work was supported by grants from the Nordic Insulin Fund, the Town of Umeå, the Swedish Medical Research Council (Project No. B69-12X-718-04A), and by a postdoctoral fellowship from the United States Public Health Service.