TheAzotobacter vinelandii chromosome

The chromosome ofAzotobacter vinelandii was digested with the restriction endonucleasesSpeI (5’-ACTAGT),DraI (5’-TTTAAA) andAsel (5’-ATTAAT) and the products were separated by pulsed-field gel electrophoresis. The sum of the sizes of the restriction fragments comes to around 4.5 megabasepairs. Our earlier studies had revealed the presence of about 80 copies ofnifH, nifD, nifK andleuB genes in a log-phase cell ofA. vinelandii. To determine whether there are multiple identical chromosomes inA. vinelandii or one large chromosome with identical segments joined in tandem, we have subjected gamma-irradiated DNA ofA. vinelandii andEscherichia coli to pulsed-field gel electrophoresis. The results suggest thatA. vinelandii chromosomes contain multiple identical chromosomes of about the same size as that ofE. coli.     

Genetic evidence for the functional redundancy of the calcineurin-and Mpk1-mediated pathways in the regulation of cellular events important for growth inSaccharomyces cerevisiae

Saccharomyces cerevisiae mutants which exhibit phenotypes (calcium resistance and vanadate sensitivity) similar to those of calcineurin-deficient mutants were isolated. The mutants were classified into four complementation groups (crv1,2,3 and4).crv1 was allelic tocnb1, a mutation in the regulatory subunit of calcineurin. The nucleotide sequences ofCRV2 andCRV3 genes which complemented thecrv2 andcrv3 mutations, respectively, are identical to those ofBCK1/SLK1/SKC1/SSP31 andMPK1/SLT2, respectively, which are both involved in the MAP kinase cascade. A calcineurin-deletion mutation (Δcnb1), which by itself has no detectable effect on growth and morphology, enhanced some phenotypes (slow growth and morphological abnormality) ofcrv2 andcrv3 mutants. These phenotypes ofcrv2 andcrv3 mutants were partially suppressed by Ca²⁺ or by overproduction of the calcineurin subunits (Cmp2 and Cnb1). Like the calcineurin-deficient mutant,crv2 andcrv3 mutants were defective in recovery from α-factor-induced growth arrest. The defect in recovery of the Δcnb1 mutant was suppressed by overexpression ofMPK1. These results indicated that the calcineurin-mediated and the Mpk1- (Bck1-) mediated signaling pathways act in parallel to regulate functionally redundant cellular events important for growth.     

DNA base composition of species of the genusSaccharomyces

DNA base compositions (GC content) ofSaccharomyces species are reported and discussed. Several amendments of the four groups given by van der Walt are suggested, viz. the transfer ofS. kluyveri to group 1, and ofS. eupagycus, S. cidri, S. montanus, S. microellipsodes andS. florentinus to group 2. The synonomy ofS. amurcae andS. cidri is suggested. The DNA base compositions revealed two possible pairs of sibling species:S. elegans andS. bailii, with a difference in GC content of 4.1%;S. dairensis andS. servazzii with a difference in GC content of ca. 3%.S. mrakii had a GC content of 47.3–48.5% the highest encountered in this genus and similar to that ofKluyveromyces thermotolerans.     

Polymorphisms of alcohol metabolizing enzyme and cytochrome P4502E1 genes in mongolian population

Although the genetic polymorphism of the alcohol-metabolizing enzymes was extensively studied at the molecular level by many investigators, the genetic polymorphism studies for ethanolmetabolizing enzymes in Mongolians are very rare. The present study was therefore performed to determine the genetic distribution of various forms of alcohol-metabolizing enzymes such as alcohol dehydrogenase 2 (ADH2, currently accepted nomenclature ADH1B), ADH3 (ADH1C), aldehyde dehydrogenase 2 (ALDH2) and cytochrome P4502E1 (CYP2E1) in 300 healthy Mongolian males. Genetic polymorphisms were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) methods. The allele frequencies ofADH2 *1 andADH2 *2 were 0.24 and 0.76;ADH3 *1 andADH3 *2 were 0.92 and 0.08;ALDH2 *1 andALDH2 *2 were 0.96 and 0.04; andCYP2E1 *C andCYP2E1 *D were 0.15 and 0.85, respectively. Compared to the results reported by other investigators, the allele frequencies ofALDH2 *2 andCYP2E1 *C among Mongolian subjects were much lower than among East Asians (Korean, Japanese, and/or Han-Chinese), while those ofADH2 andADH3 were more similar. Interestingly, this study shows that the ineffectiveALDH2 gene (ALDH2*2 allele) among Mongolians is not as common as among East Asians.     

Natural enemies ofTomicus Piniperda andIps acuminatus (Col,scolytidae) onPinus sylvestris near orléans,france: Temporal occurrence and relative abundance,and notes on eight predatory species

Ips acuminatus (Gyllenhall) andTomicus piniperda (L.) were the main scolytid beetles in Scots pine,Pinus sylvestris L., outbreak areas near Orléans, France during 1978-1979.Ips acuminatus attacked thin-bark logs whileT. piniperda attacked thick-bark logs. More than 150 species of insects were associated with these scolytids. Forty-five species (31 predators and 14 parasitoids) were confirmed as natural enemies of bark beetles. Three predators were abundant:Thanasimus formicarius L. (Col.: Cleridae),Rhizophagus depressus (F.) (Col.: Rhizophagidae) andMedetera spp. (Dipt.: Dolichopodidae). The first two were especially frequent in galleries ofT. piniperda, whileMedetera spp. were more abundant in galleries ofI. acuminatus. The main parasitoids wereRhopalicus tutela (Walker) andR. brevicornis Thomson (Hym.: Pteromalidae),Coeloides abdominalis Zetterstedt andC. melanostigma Strand,Dendrosoter middendorfi Ratzeburg andD. hartigii Ratzeburg, andSpathius rubidus Rossi (Hym.: Braconidae). These parasitoids are polyphagous. However,C. abdominalis was obtained fromT. piniperda but not fromI. acuminatus, while 5.rubidus andD. hartigii were obtained fromI. acuminatus but not fromT. piniperda. Temporal and relative abundance of natural enemies ofT. piniperda andI. acuminatus were studied. The predatorsR. depressus andT. formicarius had complementary limiting effects on bark beetles as adults and larvae ofR. depressus fed mainly on scolytid eggs, whileT. formicarius adults attacked scolytid adults and the clerid larvae preyed upon scolytid larvae. The predatory pressure applied byT. formicarius andR. depressus toT. piniperda early during the spring was later complemented by a series of parasitoids and other predators. This sequential timing of the natural enemies ofT. piniperda suggests that the interactions among the guild are more complementary than adverse. Differential timing of the natural enemies in logs infested byI. acuminatus and some evidence of competition between the predatorsMedetera spp. and parasitoids suggested a less effective control of this scolytid. Number and duration of larval instars were determined, and measurements of predatory activity were made forThanasimus formicarius, Rhizophagus depressus,Hypophloeus fraxini Kugelann (Col.: Tenebrionidae),Platysoma frontale Paykull (Col.: Histeridae), andXylocoris cursitans (Fallen) (Het.: Anthocoridae). Predatory activity was evaluated for last instar larvae and adults ofScoloposcelis obscurella (Zetterstedt) (Het.: Anthocoridae), and for last instar larvae ofMedetera sp. andLonchaea collini Hackman (Dipt.: Lonchaeidae)     

Revision of the bulbous Iridaceae of North America

The native bulbous Iridaceae of North America excluding Mexico comprise seven species in four genera. The type species ofAlophia Herb. (1836) is shown to belong toEustylis Engelm. & Gray (1836), hence the latter genus is reduced to synonymy. The well known genusAlophia (sensu auct. non Herb.) (Herbertia Sweet) now takes the nameTrifurcia. As a result of the new interpretation ofAlophia, new combinations are made for the North American and Latin American species ofTrifurcia andAlophia. New chromosome counts are given forNemastylis floridana (2n = 56) andTrifurcia lahue (2n = 56).     

Notes on calycophyllous Rubiaceae. Part I. Morphological comparisons of the genera Chimarrhis,Bathysa, and Calycophyllum,with new combinations and a new species,Chimarrhis gentryana

A comparison of some genera of the Condaminecae (Rubiaceae) with a few taxa of closely related tribes (Rondeletieae, Calycophylleae, and Cinchoneae) revealed that some species ofChimarrhis (Condamineeae s. 1.),Bathysa (Rondeletieae), andCalycophyllum (Calycophylleae) are often misassigned to genera. The taxonomic significance of calycophylls is discussed; the generic boundaries ofChimarrhis, Bathysa, andCalycophyllum are reevaluated; and their similarities and differences are discussed. As a result, a new calycophyllous species ofChimarrhis from the Amazon,C. gentryana, is described, two of its species are transferred toBathysa (B. Bathysoides, B. perijaënsis), and one species ofBathysa (B. difformis) is reduced to synonymy underChimarrhis (C. turbinata).     

Sarcostemma R.Br. (Apocynaceae — Asclepiadoideae) — a controversial generic circumscription reconsidered: Evidence fromtrnL-F spacers

The polyphyly ofSarcostemma sensu latu, suspected on morphological and karyological reasons is confirmed by analysis of thetrnL-F spacer region. With the exception ofCynanchum montevidense (subgen.Mellichampia, Sundell 1981), Old World and New World taxa belong to different clades.Sarcostemma sensu stricto andPlatykeleba show a strong affinity to Old WorldCynanchum; the affinities ofOxystelma cannot be determined at present.Philibertia andBlepharodon are sister groups, both are sister toFunastrum, andPentacyphus is basal to the New World clade.     

Zur systematischen Stellung mesozoischer und tertiärer Mecopteren einschließlichEoses triassica Tindale (angeblich Lepidoptera) (Insecta,Holometabola)

Eoses triassica Tindale, by many authors regarded as the oldest representative of the Lepidoptera, is a member of the order Mecoptera.Orthophlebia reticulata (Handlirsch 1906), andO. latipennis (Handlirsch 1906) from the Upper Lias of Mecklenburg (Germany) are synonyms ofO. Limnophila (Handlirsch 1906).O. elegans (Handlirsch 1939) is a synonym ofO. vicina (Handlirsch 1939). TheOrthophlebioides-problem is discussed in the light of Handlirsch’s argumentation. Contrary to Handlirsch’s opinion this genus represents the hind wings ofOrthophlebia as previous authors suggested. Reasons are offered for the synonymy ofSynorthophlebia withOrthophlebia andMesopanorpa, respectively.Limfiordia from the Mo-clay of the Limfjord area (Denmark) is not a scorpion-fly but a member of the Fulgoriformes (Auchenorrhyncha).Parachorista Lin 1976 (nom. praeocc, nonParachorista Tillyard 1926) from the Jurassic of China does not belong to the Orthophlebiidae (Mecoptera) but to the Trichoptera.     

Insecticidal effectiveness ofMammea Americana (Guttiferae) extracts on larvae ofDlabrotica Virgifera Virgifera (Coleoptera:Chrysomelidae) andTrichoplusia Ni (Lepidoptera:Noctuidae)

Seed and leaf extracts ofMammea americana (mamey apple) have a historical use as a biopesticide with the active components previously characterized. We reexamined the utility of this natural bioinsecticide in light of existing sources of material as a by-product of the fruit processing industry. Our results addDiabrotica virgifera virgifera andTrichoplusia ni to the list of insects which are susceptible to the insecticidal ingredients ofM. americana and confirms earlier reports of activity againstBlatella germanica, Periplaneta americana, andPlutella xylostella. We report LD5Os for crude hexane extracts ofM. americana leaves and seeds againstT. ni. These materials represent renewable sources of bioinsecticides for agriculture, and should regenerate interest in coumarin-type compounds for novel pesticidal action.     

Mutations in somePolycomb group genes ofDrosophila interfere with regulation of segmentation genes

Mutations in severalPolycomb (Pc) group genes cause maternal-effect or zygotic segmentation defects, suggesting thatPc group genes may regulate the segmentation genes ofDrosophila. We show that individuals doubly heterozygous for mutations inpolyhomeotic and six otherPc group genes show gap, pair rule, and segment polarity segmentation defects. We examined double heterozygous combinations ofPc group and segmentation mutations for enhancement of adult and embryonic segmentation defects.Posterior sex combs andpolyhomeotic interact withKrüppel ² and enhance embryonic phenotypes ofhunchback andknirps, andpolyhomeotic enhanceseven-skipped. Surprisingly, flies carrying duplications ofextra sex combs (esc), that were heterozygous for mutations ofeven-skipped (eve), were extremely subvital. Embryos and surviving adults of this genotype showed strong segmentation defects in even-numbered segments. Antibody studies confirm that expression ofeve is suppressed by duplications ofesc. However,esc duplications have no effect on other gap or pair rule genes tested. To our knowledge, this is only the second triplo-abnormal phenotype associated withPc group genes. Duplications of nine otherPc group genes have no detectable effect oneve. Expression ofengrailed (en) was abnormal in the central nervous systems of mostPc group mutants. These results support a role forPc genes in regulation of some segmentation genes, and suggest thatesc may act differently from otherPc group genes.     

Convolvulus grandiflorus Jacq. (Convolvulaceae) re-examined

Convolvulus grandiflorus Jacq. has been treated as a synonym ofOperculina ventricosa andStictocardia tiliifolia. It is here accepted as identifiable withIpomoea (sect.Calonyction)macrantha which is the correct name for Jacquin’s taxon. Full synonymies ofIpomoea macrantha andOperculina ventricosa are given, along with a comment about a variant occurring in Micronesia.     

Population studies in Goodyera (Orchidaceae) with emphasis on the hybrid origin of G. Tesselata

Morphological, cytological, and paper Chromatographic studies of populations from northern Michigan and examination of herbarium specimens from throughout North America were used to clarify the relationships ofGoodyera oblongifolia, G. repens var.ophioides, andG. tesselata. A canonical analysis of morphological data from mixed populations of these three species depictsG. tesselata as intermediate betweenG. oblongifolia andG. repens var.ophioides. The latter two species are diploid (2n = 30) andG. tesselata is tetraploid (2n = 60). Triploids (2n = ca. 45) were found in two mixed-species populations in northern Michigan.Goodyera tesselata produces three phenolic compounds present inG. oblongifolia and five different compounds present inG. repens var.ophioides. The range ofG. tesselata is confined to glaciated territory (except for two stations) in northeastern North America where the postglacially produced ranges ofG. oblongifolia andG. repens var.ophioides overlap. However,G. tesselata is quite abundant in areas outside the region of sympatry of the other two species. Based on this evidence, it is postulated thatG. tesselata is an allotetraploid species which resulted from hybridization betweenG. oblongifolia andG. repens var.ophioides during early post-Pleistocene. The slightly earlier blooming season ofG. tesselata may have been selected for to provide a measure of reproductive isolation between the tetraploid and its parents and to adapt the new species to the rather short growing season of northeastern North America.     

The mountain forests of british columbia and the american northwest: Floristic patterns and syntaxonomy

An overview of the montane and subalpine forests ofAbies lasiocarpa, Picea engelmannii, Abies amabilis andTsuga mertensiana of northwestern North America is provided based on 541 relevés of forest vegetation from coastal and inland British Columbia, Washington and northwestern Montana. A new classification is proposed based on an examination of the floristic patterns across these communities. Owing to their broadscale floristic similarities, coastal subalpineAbies amabilis-Tsuga mertensiana forests and inland forests ofAbies lasiocarpa, Picea engelmannii, P. glauca, Thuja plicata andTsuga heterophylla are combined into a single order,Thujetalia plicatae. The floristic patterns within this order in turn support the recognition of four alliances. These are (1)Tsugion mertensianae, including coastal and inland subalpine forests ofTsuga mertensiana, Abies amabilis, A. lasiocarpa andPicea engelmannii, with deep winter snowpacks and an often luxuriously developed shrub layer; (2)Abieti-Tsugion heterophyllae all. nov., including mesic inland montaneThuja plicata-Tsuga heterophylla andAbies lasiocarpa-Picea engelmannii forests and related southern borealAbies lasiocarpa-Picea glauca communities; (3)Gymnocarpio-Abietion lasiocarpae, including moist coastal and inland forests dominated by a fern-rich understory andOplopanax horridus; and (4)Lysichito-Chamaecyparidion nootkatensis, which includes wet coastal subalpine forests withLysichiton americanum. A total of five new associations are described, bringing the number of recognized associations within the order to twenty-five. An extensive synonymy and crosswalk to other classification systems is provided.     

New genera and species of ericaceae (Vaccinieae) from Costa Rica and Panama

Two new monotypic genera,Didonica andUtleya, are described, withD. pendula from Panama andU. costaricensis from Costa Rica.Disterigma trimera (Panama),D. utleyorum (Costa Rica, Panama, Colombia, and Ecuador),Lateropora santafeensis (Panama),Lysiclesia panamensis (Panama),Macleania talamancensis (Costa Rica),Themistoclesia costaricensis (Costa Rica) andT. horquetensis (Panama),Vaccinium costaricense andV. orosiense (both from Costa Rica) and V.jefense (Panama) are all described as new. New combinations are provided for the PanamanianVaccinium floccosum (=Symphysia floccosa) and the West IndianVaccinium racemosum (=Symphysia racemosa). Keys are provided for the Central American species ofDisterigma andThemistoclesia, the species ofLateropora andLysiclesia, and the Costa Rican and Panamanian species ofVaccinium. Six new species are illustrated.     

Chromosome numbers of Orthocarpus and related monotypic genera (Scrophulariaceae: Subtribe castillejinae)

A chromosome number ofn=12 is reported for the three monotypic genera of subtribe Castillejinae:Clevelandia beldingii, Gentrya racemosa, andOpicopephalus angustifolius. Chromosome numbers ofOrthocarpus correspond mostly with current infrageneric classification. SubgenusTriphysaria hasn=11.Orthocarpus sectionsCastillejoides andCordylanthoides, which are closely related toCastilleja (x=12) and the three monotypic genera above, haven=12 with aneuploid reductions ton=10 inO. linearilobus andn=11 inO. lacerus (a species also withn=12). Tetraploids are found in two species.O. brevistylus (n=24) andO. hispidus (n=12, 24). The polyploid.O. laciniatus (n=36, 48) of Peru is postulated to be of hybrid origin between a species ofCastilleja andOrthocarpus attenuatus. SubgenusOrthocarpus sectionOrthocarpus, which hasn=14 in all species except.O. bracteosus (n=15), stands apart both morphologically and in chromosome number from the remainder of the genus.     

Fatty acids and sterols of selected hyphochytriomycetes and chytridiomycetes

The fatty acids and sterols of eight Chytridiomycetes and two Hyphochytriomycetes, and fatty acids of the OomycetePythium gracile, were analyzed by gas-liquid chromatography. In addition to the fatty acids anticipated for fungi, the two Hyphochytriomycetes (Hyphochytrium catenoides andRhizidiomyces apophysatus) and four of the Chytridiomycetes (Catenaria anguillulae, Blastocladiella emersonii, Monoblepharella sp., andAllomyces macrogynus) contained arachidonic acid as a major fatty acid of the polar lipid fraction, and this fatty acid was detected as a minor component ofRhizophlyctis rosea andSpizellomyces punctatum. Eicosapentaenoic acid constituted 4.6% of the polar lipid fatty acids inMonoblepharella sp., and trace amounts were detected in several other species. Both the gamma (ω-6) and alpha (ω-3) isomers of linolenic acid were detected in all of the species analyzed. Cholesterol was the predominant (≥73%) sterol ofB. emersonii, R. rosea, A. macrogynus, andChytridium confervae, and a minor (<12%) component ofC. anguillulae, andH. catenoides. The major sterols of the other species included lanosterol (C. anguillulae, 45%), stigmasta-5,22-dien-3β-ol (H. catenoides, 51%), 24-ethyl-cholesterol (S. punctatum, 38%;H. catenoides, 17%;Monoblepharella sp., 70%; andR. apophysatus, 84%), 24-methyl-cholesterol (H. catenoides, 23%;R. apophysatus, 14%;S. punctatum, 53%), and 24-methylene cholesterol (Rhizophydium sphaerotheca, 51%). Neither ergosterol nor fucosterol was detected in any of the species studied.     

TheAspergillus nidulans geneschsA andchsD encode chitin synthases which have redundant functions in conidia formation

We previously isolated three chitin synthase genes (chsA, chsB, andchsC) fromAspergillus nidulans. In the present work, we describe the isolation and characterization of another chitin synthase gene, namedchsD, fromA. nidulans. Its deduced amino acid sequence shows 56.7% and 55.9% amino acid identity, respectively, with Cal1 ofSaccharomyces cerevisiae and Chs3 ofCandida albicans. Disruption ofchsD caused no defect in cell growth or morphology during the asexual cycle and caused no decrease in chitin content in hyphae. However, double disruption ofchsA andchsD caused a remarkable decrease in the efficiency of conidia formation, while double disruption ofchsC andchsD caused no defect. Thus it appears thatchsA andchsD serve redundant functions in conidia formation.