Meiotic studies ofElymus nutans andE. jacquemontii (Poaceae,Triticeae) and their hybrids withPseudoroegneria spicata and seventeenElymus species

Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.     

Meiotic analysis ofElymus caucasicus,E. longearistatus,and their interspecific hybrids with twenty-threeElymus species (Triticeae,Poaceae)

Interspecific hybridizations were carried out between the two tetraploidsElymus caucasicus andE. longearistatus, and 23 tetraploids and hexaploids ofElymus containing SH, SY, SYH, and SYW genomes and representing various geographical regions. Meiotic pairing was studied in the two target species and their hybrids. It is concluded from this study that (i) interspecific hybridization is fairly easy to perform although strong reproductive barriers exist between the species; (ii)Elymus caucasicus andE. longearistatus are allotetraploids, and share the diverged SY genomes; (iii) the divergence of SY genomes is correlated with the geographic distance between theElymus spp. studied.     

The chromosomal locations and linkage relationships of the structural genes for the prolamin storage proteins (secalins) of rye

Summary Rye secalins are a polymorphic mixture of polypeptides which are classified into four major groups. Previous studies have shown that the structural genes for two of the groups (the -secalins and 40K -secalins) are located on the short arm of chromosome 1R and those for a third group (the high molecular weight secalins) on the long arm of the same chromosome. Analysis of F₂ grain from crosses between inbred lines of S. cereale shows that the structural genes for the -secalins (designated Sec 1) and the high molecular weight secalins (designated Sec 3) are loosely linked (40.8 ±3.76% recombination, 57.4 ± 11.30 cM). Analysis of wheat rye addition lines shows that the structural genes for the 75K -secalins are present on chromosome 2R. This locus is provisionally designated Sec 2. These genes are probably derived from those for the 40K -secalins by duplication, divergence and translocation. Analysis of secalin fractions from wild species of rye shows that all contain 75K -secalins, indicating that the duplication and divergence, if not the translocation, occurred before speciation of the genus.     

Sex determination in the genus Oreochromis

Summary Sex ratios from 62 single-pair matings of normal broodstock O. aureus were highly heterogeneous with an overall deficit of males (41.4%). Peaks in the sex ratio frequency distribution occurred at 11, 35 and 13 (malefemale). Hybridisation of O. aureus with O. mossambicus, O. spilums and O. niloticus produced highly variable sex ratios, suggesting a complexity of hybrid sex determination. Few valid inferences could be made regarding intraspecific sex determination from these hybrid data. Sex ratios from progeny testing of sex-reversed males (13) and most sex-reversed females (10) provide evidence for female heterogamety in O. aureus. Several aberrant ratios observed suggest Mendelian inheritance of an autosomal recessive gene (F,f), epistatic to the major sex-determining gene (W,Z). Sex ratios of triploids and gynogens support the hypothesis of recombination between the centromere and the major sex-determining locus. Progeny testing of a female mitogyne demonstrated the viability of a novel WW superfemale, which gave only female offspring. Not all data could be explained by a two-factor model of sex determination. Further exceptional sex ratios may be accounted for by rare autosomal or environmental sex-modifying factors. It is concluded that O. aureus has a multifactorial mechanism of sex determination with the underlying primary mechanism of female heterogamety.     

Curdlan and other bacterial (1→3)-β-d-glucans

Three structural classes of (13)--d-glucans are encountered in some important soil-dwelling, plant-associated or human pathogenic bacteria. Linear (13)--glucans and side-chain-branched (13,12)--glucans are major constituents of capsular materials, with roles in bacterial aggregation, virulence and carbohydrate storage. Cyclic (13,16)--glucans are predominantly periplasmic, serving in osmotic adaptation. Curdlan, the linear (13)--glucan from Agrobacterium, has unique rheological and thermal gelling properties, with applications in the food industry and other sectors. This review includes information on the structure, properties and molecular genetics of the bacterial (13)--glucans, together with an overview of the physiology and biotechnology of curdlan production and applications of this biopolymer and its derivatives.     

<Emphasis Type="Italic">Uncisudis posteropelvis</Emphasis>, a new species of barracudina (Aulopiformes: Paralepididae) from the western North Pacific Ocean

Six specimens (2 flexion larvae: 9.5–10.4mm in notochord length; 4 postflexion larvae: 12.3–18.2mm in standard length) collected from the western North Pacific are tentatively ascribed to the genus Uncisudis of the tribe Lestidiini of the subfamily Paralepidinae (Paralepididae) in sharing remarkably elongate and filamentous pelvic fin rays, their tips reaching the origin of the anal fin. They are described as Uncisudis posteropelvis sp. nov. in uniquely having the insertion of pelvic fins closer to the origin of anal fin than to the posterior end of dorsal fin base among lestidiine species. Addition to this character, the new species has remarkably elongate and filamentous dorsal fin rays, the short distance between anus and origin of anal fin (4.2–6.1% of standard length, SL), the posteriorly located pelvic fins (prepelvic length 69.4–71.5% SL), dorsal fin rays 10, anal fin rays 28–29, myomeres 41–42+38–40=80–81 (vertebrae 38+41=79), and peritoneal pigment spots 11–12. The occurrence of larvae differing in pigment pattern from the present new species suggests another undescribed species of Uncisudis in the western South Pacific.     

A Cytogenetic Study of the Leaf Beetle Genus Cyrtonus (Coleoptera, Chrysomelidae)

The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xy_p male meioformula, three have 2n=40 and 19+Xy_p and one 2n=46 and 22+Xy_p. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.     

Sialic acid-containing lipopolysaccharides in purple nonsulfur bacteria

Lipopolysaccharides (LPS) from a number of purple nonsulfur bacteria and of phylogenetically related species were analyzed for the presence of sialic acid by gas chromatography/mass spectrometry. Species and strains of the genera Rhodobacter, Rhodopseudomonas, Rhodomicrobium, Rhodospirillum, Rhodocyclus and Rhodopila were investigated, sialic acid, however, was found only in the genus Rhodobacter. It occurs in strains of Rhodobacter capsulatus, R. sphaeroides, R. sulfidophilus and R. veldkampii. All these species belong to the -3 subgroup of purple bacteria as defined by 16S rRNA catalogues. Approximately equimolar ratios of sialic acid and of 2-keto-3-deoxy-octonate (KDO) were found in isolated LPSs. Sodium deoxycholate gel electrophoresis of these LPS-samples also suggested a location of sialic acid in the LPS core region. Sialic acid was present only in those LPSs, which exhibited a complete core region.Abbreviations LPS Lipopolysaccharide - Neu5Ac N-acetylneuraminic acid - KDO 2-Keto-3-deoxy-octonate - Neuß2Me neuraminic acid-2-methyl glycoside - DOC sodium deoxycholate - PAGE polyacrylamide gel electrophoresis - HPLC high performance liquid chromatography - TLC thin layer chromatography     

The systematics of Porphyra: character evolution in closely related species

Isozymes, vegetative and reproductive morphology, seasonality, vertical and geographic distributions and chromosomes were compared for six pairs of putative sibling species of Porphyra (P. abbottae/P. torta, P. fallax subsp. fallax/P. fallax subsp. conwayae, P. amplissima/P. cuneiformis, P. fucicola/P. leucostica, P. miniata/P. variegata, P. umbilicalis/P. umbilicalis) and among five species in a complex (P. brumalis, P. kurogii, P. linearis, P. pseudolinearis, and P. purpurea.) Geographic distribution and zymograms for certain proteins showed the greatest change between species pairs: only one pair of species had identical distributions, and most species pairs were disjunct; every species had a different allozyme for GOT-1, whereas all species had apparently identical proteins for phycoerythrin. Seasonality and habitat exhibited moderate differentiation: Northeast Pacific sibling species were characterized by a high intertidal winter species pairing with a mid intertidal spring species, whereas all but one of the other species pairs exhibited nearly identical vertical distributions and seasonalities. There were few changes in morphology: most species pairs had essentially identical morphologies and coloration and the same arrangement of reproductive cells. Chromosome numbers and karyotypes were identical for species pairs and in the species complex. These results provide evidence for different rates of evolution of different characters in the genus Porphyra.     

Protein engineering in the α-amylase family: catalytic mechanism,substrate specificity,and stability

Most starch hydrolases and related enzymes belong to the -amylase family which contains a characteristic catalytic (/)₈-barrel domain. Currently known primary structures that have sequence similarities represent 18 different specificities, including starch branching enzyme. Crystal structures have been reported in three of these enzyme classes: the -amylases, the cyclodextrin glucanotransferases, and the oligo-1,6-glucosidases. Throughout the -amylase family, only eight amino acid residues are invariant, seven at the active site and a glycine in a short turn. However, comparison of three-dimensional models with a multiple sequence alignment suggests that the diversity in specificity arises by variation in substrate binding at the loops. Designed mutations thus have enhanced transferase activity and altered the oligosaccharide product patterns of -amylases, changed the distribution of -, - and -cyclodextrin production by cyclodextrin glucanotransferases, and shifted the relative -1,4:-1,6 dual-bond specificity of neopullulanase. Barley -amylase isozyme hybrids and Bacillus -amylases demonstrate the impact of a small domain B protruding from the (/)₈-scaffold on the function and stability. Prospects for rational engineering in this family include important members of plant origin, such as -amylase, starch branching and debranching enzymes, and amylomaltase.Abbreviations CGTase cyclodextrin glucanotransferase - SBD starch binding domain - TAA taka-amylase A - TIM triose-phosphate isomerase. The mutations are described with the one-letter code, i.e. D164A is a mutant in which A in the mutant is substituted for D in the wild-type.     

11 S seed storage proteins fromHelianthus species (Compositae): Biochemical,size and charge heterogeneity

The seeds of 19 sunflower species were compared on the basis of their protein contents and the relative proportions of their protein fractions. The globulin content varied from 50% to about 70% and the albumin content from 18% to 35% according to the species. The level of intermediateMr polypeptides showed a great variability (9.6 to 24.3%). Comparative studies onMr polymorphism were carried out by means of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of non reduced and/or reduced samples using both mono- and bidimensional procedures. Polypeptide constituents of helianthinin were compared including both number and molecular size (cultivatedH. annuus was used as a standard). Studies focused on differences observed between the major two (Mr 38 000), (Mr 32 000) and (Mr 25 500), (21 000) polypeptides families constituting the main A, B, and C subunits. and polypeptides analyses permit to discriminate easilyH. petiolaris from the other species. Charge polymorphism was studied using isoelectric focusing (IEF) and IEF-PAGE in mono and bidimensional procedures in the presence or absence of 2-mercaptoethanol (2-ME). Only a specific ₄ polypeptide enables an easy discrimination betweenH. petiolaris and all the other species. Detailed nomenclature of the , and , polypeptides constituting the different helianthinin globulin subunits is given via the results of pI andMr analyses. Monodimensional IEF patterns of the more basic albumins (pI > 8.0) appear to provide a more valuable approach to identifying specific protein markers.     

The carotenoids of Flavobacterium strain R1560

The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, -carotene (7,8,7,8-tetrahydro-, -carotene plus 7,8,11,12-tetrahydro-, -carotene), neurosporene, lycopene, -zeacarotene, -carotene, -carotene, -cryptoxanthin, rubixanthin, 3-hydroxy--zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of half-molecule reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.     

Genetic analysis of brown planthopper resistance in twenty varieties of rice,Oryza saliva L.

Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu.     

Analysis of the effect of rye chromosomes 4R, 6R and telomeric heterochromatin on 7R on homologous chromosome pairing in pentaploid hybrids (AABBR,AABBD)

Summary Meiotic pairing in Triticum turgidum cv. Ma (4x) with a mean chiasmata frequency of 27.16 per cell was compared with chiasmata frequencies in its hybrids with several triticale strains, Chinese Spring wheat and its addition lines for Imperial rye chromosomes 4R and 6R. In hybrids between Ma and x Triticosecale cv. Rosner the chiasmata frequency was marginally reduced by an average of 1.25%, by 8.8% in hybrids with x Triticosecale cv. DRIRA HH and by 6.7% with DRIRA EE (lacking 90% telomeric heterochromatin from chromosome arm 7RL). In pentaploid hybrids between Ma and T. aestivum cv. Chinese Spring the reduction was an average of 10.30%, while addition lines with rye chromosome 6R reduced chiasmata frequencies by an average of 7.4% and rye addition line for 4R showed the greatest depression in chiasmata frequency in hybrids by a 25.04% reduction. An interchange difference involving long chromosome segments was observed between Ma and Rosner.Contribution No. 819 Ottawa Research Station     

Carbohydrates of influenza virus. Structure of the oligosaccharides linked to asparagines 406 and 478 in the hemagglutinin of fowl plague virus,strain dutch

Fowl plague virus, strain Dutch, was metabolically labeled withd-[2-³H]mannose, or withd-[6-³H]glucosamine, and the small subunit (HA₂; 0.8 mg in total) of the viral hemagglutinin was isolated by preparative sodium dodecylsulfate-polyacrylamide gel electrophoresis. After proteolytic digestion, the radioactive oligosaccharides were sequentially liberated from the glycopeptides by treatment with different endo--N-acetylglucosaminidases and with peptide:N-glycosidase or, finally, by hydrazinolysis. In this manner, four groups of glycans could be obtained by consecutive gel filtrations and were subfractionated by HPLC. The structures of the individual oligosaccharides were analyzed by micromethylation, by acetolysis or by digestion with exoglycosidases. The major species amongst the high mannose glycans at Ans-406 of the viral glycopolypeptide were found to be Man1-2Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNac1-4GlcNAc and Man1-3(Man1-2Man1-6)Man1-6(Man1-2Man1-2Man1-3)Man1-4GlcNAc1-4GlcNAc, while the complex glycans at Asn-478 are predominantly GlcNAc1-2Man1-3(GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc (lacking, in part, one of the outerN-acetylglucosamine residues) and GlcNAc1-2Man1-3(Gal1-4GlcNAc1-2Man1-6)Man1-4GlcNAc1-4GlcNAc.Abbreviation BSA bovine serum albumin - endo D (F,H) endo--N-acetyl-d-glucosaminidase D (F,H) - HA hemagglutinin (HA₁, large subunit of HA - HA₂ small subunit - FPV fowl plague virus - PNGase F peptide:N-glycosidase F - SDS sodium dodecylsulfate     

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.     

AT-1 Receptor and Phospholipase C Are Involved in Angiotensin III Modulation of Hypothalamic Noradrenergic Transmission

SUMMARY 1. We previously reported that angiotensin III modulates noradrenergic neurotransmission in the hypothalamus of the rat. In the present work we studied the effects of angiotensin III on norepinephrine release and tyrosine hydroxylase activity. We also investigated the receptors and intracellular pathways involved in angiotensin III modulation of noradrenergic transmission.2. In rat hypothalamic tissue labeled with [³H]norepinephrine 1, 10, and 100 nM and 1 M losartan (AT1 receptor antagonist) had no effect on basal neuronal norepinephrine release, whereas 10 and 100 nM and 1 M losartan partially diminished norepinephrine secretion evoked by 25 mM KCl. The AT2 receptor antagonist PD 123319 showed no effect either on basal or evoked norepinephrine release. The increase in both basal and evoked norepinephrine output induced by 1 M angiotensin III was blocked by 1 M losartan, but not by 1 M PD 123319.3. The phospholipase C inhibitor 5 M neomicin inhibited the increase in basal and evoked norepinephrine release produced by 1 M angiotensin III.4. Tyrosine hydroxylase activity was increased by 1 M angiotensin III and this effect was blocked by 1 M LST and 5 M neomicin, but not by PD 123319. On the other hand, 1 M angiotensin III enhanced phosphatidyl inositol hydrolysis that was blocked by 1 M losartan and 5 M neomicin. PD 123319 (1 M) did not affect ANG III-induced phosphatidyl inositol hydrolysis enhancement.5. Our results confirm that angiotensin III acts as a modulator of noradrenergic transmission at the hypothalamic level through the AT1-phospholipase C pathway. This enhancement of hypothalamic noradrenergic activity suggests that angiotensin III may act as a central modulator of several biological processes regulated at this level by catecholamines, such as cardiovascular, endocrine, and autonomic functions as well as water and saline homeostasis.     

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.     

The impact of domestication on the genetic variability in the orange carrot,cultivated Daucus carota ssp. sativus and the genetic homogeneity of various cultivars

Summary Isozyme analysis of wild and domesticated accessions indicated that domestication of the cultivated carrot Daucus carota ssp. sativus resulted in an insignificant reduction of all genetic variability and genetic distance estimates. Although they are less variable genetically, cultivated forms maintain a high proportion of observed heterozygosity. Relative to the overall genetic variability of the species, samples from four common cultivars Red Cored Chantenay, Scarlet Nantes, Danvers Half Long and A Plus demonstrated a high degree of genetic similarity. This is attributed to the recent development of orange cultivars and the limited gene pool utilized in their development.     

Steroid Polyols from the Far Eastern Starfish Henricia sanguinolenta and H. leviuscula leviuscula

Two new asterosaponins, (20R)-3-O--D-(2-O-methylxylopyranosyl)-24-propylcholest-4-ene-3,6,8,15,16,29-hexaol (sanguinoside A) and (20R,24S)-3-O--D-(2,3,4-tri-O-methylxylopyranosyl)-5-cholestane-3,4,6,8,15,24-hexaol (sanguinoside B), were isolated from two species of Pacific Far Eastern Starfish Henricia sanguinolenta and H. leviuscula leviuscula, collected in the Sea of Okhotsk. Both glycosides contain aglycones with pentahydroxysteroid nuclei of similar structures, which are substituted at the 3-hydroxy group with differently methylated -D-xylosyl residues. Sanguinoside A has an unusual structure of its aglycone side chain, whereas sanguinoside B has a unique permethylated carbohydrate chain. In addition, laevisculoside G, a known glycoside, was identified in the H. leviuscula starfish. The structures of the isolated glycosides were established by interpreting their spectral data and by comparing their spectral characteristics with those of known compounds.