Germline transmission of exogenous genes in chickens using helper-free ecotropic avian leukosis virus-based vectors

We have used vectors derived from avian leukosis viruses to transduce exogenous genes into early somatic stem cells of chicken embryos. The ecotropic helper cell line, Isolde, was used to generate stocks of NL-B vector carrying theNeo ^r selectable marker and theEscherichia coli lacZ gene. Microinjection of the NL-B vector directly beneath unincubated chicken embryo blastoderms resulted in infection of germline stem cells. One of the 16 male birds hatched (6.25%) from the injected embryos contained vector DNA sequences in its semen. Vector sequences were transmitted to G₁ progeny at a frequency of 2.7%.Neo ^r andlacZ genes were transcribedin vitro in chicken embryo fibroblast cultures from transgenic embryos of the G₂ progeny.     

Studies on systematic embryology inScilla (Hyacinthaceae)

Scilla persica and 5 species of the so-calledS. hohenackeri group, namely,S. furseorum, S. puschkinioides, S. vvedenskyi, S. hohenackeri, andS. greilhuberi, have been investigated embryologically with special reference to embryo sac and endosperm development.Polygonum-type embryo sac development was stated inS. puschkinioides andS. greilhuberi. 8-nucleate, normally structured embryo sacs, which could not be specified further due to sparse availability of the material, were stated inS. furseorum, S. vvedenskyi, andS. hohenackeri. InS. persica the embryo sac develops according to the bisporicAllium-type. In most species endosperm development was stated to be nuclear, exceptS. hohenackeri, where the type could not be specified. Other traits of possible taxonomic significance are the number of layers in the outer integument, which is mostly 4, or 5–6 inS. furseorum, and the occurrence of polyploid versus haploid and early degenerating antipodal nuclei, the latter occurring only inS. persica andS. furseorum. These embryological characters may be useful for assessing taxonomic relationship of the present species with other allied groups withinScilla, in particular, theS. siberica alliance,S. messeniaca, and theS. bifolia alliance. TheAllium-type embryo sac, which occurs inS. persica, is also characteristic for theS. siberica alliance, and may be a common derived character. Lack of antipodal polyploidization, as characteristic forS. persica andS. furseorum, occurs also in theS. siberica alliance, and is perhaps another common derived trait indicating phylogenetic relationship. Nuclear endosperm development is more frequent in spring-flowering squills than helobial development, which has previously been stated inS. messeniaca, some species of theS. siberica alliance, and inS. litardierei. While helobial endosperm may be primitive forHyacinthaceae in general, it may, by reversal, also occur as a derived character, at least in some species of theS. siberica alliance.     

Molecular analysis of theArabidopsis pattern formation geneGNOM: gene structure and intragenic complementation

TheGNOM gene is required for pattern formation along the main body axis of the embryo in the flowering plantArabidopsis thaliana. Mutations in theGNOM gene alter the asymmetric division of the zygote and interfere with the formation of distinct apical-basal regions in the developing embryo. We have isolated theGNOM gene by positional cloning, characterised its structure and determined the molecular lesions in mutant alleles. Although the predicted 163 kDa GNOM protein has a conserved domain in common with the yeast secretory protein Sec7p, it is most closely related in size and overall similarity to the product of the yeastYEC2 gene, which is not essential for cell viability. Four fully complementinggnom alleles carry missense mutations in conserved regions, seven partially complementing alleles have premature stop codon mutations and two non-complementing alleles have splice-site lesions. Our results suggest that the GNOM protein acts as a complex of identical subunits and that partial complementation may involve low levels of full-length protein generated by inefficient translational read-through.Communicated by H. Saedler     

Implications ofrbcL sequence data for higher order relationships of theLoasaceae and the anomalous aquatic plantHydrostachys (Hydrostachyaceae)

Subclass and ordinal relationships ofLoasaceae, a small predominately New World family, are examined usingrbcL sequence data. Sequences were examined for eight of the fifteen genera of theLoasaceae and the morphologically anomalous aquatic genusHydrostachys (Hydrostachyaceae). Parsimony analyses of these sequences, combined with previously publishedrcbL data, indicate thatLoasaceae belong in theCornales, and are the sister group ofHydrangeaceae. This agrees with phylogenies based on chloroplast DNA inverted repeat restriction site, morphological and chemical data. TherbcL trees support the monophyly of theLoasaceae and most generic relationships correspond to current subfamily divisions. TherbcL phylogeny also provides the first suggestion thatHydrostachys is allied with theHydrangeaceae in theCornales.     

Phyletic and evolutionary relationships ofBrachyscome lineariloba (Compositae)

A comparison of karyotypes ofBrachyscome breviscapis (2n = 8),B. lineariloba cytodemes E (2n = 10), B (2n = 12) and C (2n = 16) suggests that these species have a homoelogous basic set of four chromosome pairs, two large pairs and two small, and that theB. lineariloba cytodemes E, B and C are related toB. breviscapis by successive additions of small chromosomes. A pronounced asynchrony of chromosome condensation between these large and small chromosomes has been observed. In the artificial hybrids betweenB. dichromosomatica (2n = 4) ×B. breviscapis, and theB. lineariloba cytodemes, theB. dichromosomatica chromosomes are similar in size and condensation behaviour to the small chromosomes ofB. breviscapis and ofB. lineariloba cytodemes E, B and C. Meiotic pairing in these hybrids also demonstrates the strong affinities between these chromosomes. It is suggested thatB. breviscapis may be of amphidiploid origin between a species with two large early condensing chromosome pairs and another,B. dichromosomatica-like species with two small late condensing pairs. It seems most likely that the additional small and late condensing chromosomes inB. lineariloba cytodemes E, B and C are derived from theB. dichromosomatica-like parent, and that each addition increases vigour, fecundity and drought tolerance, allowing these cytodemes to colonize more open and arid environments. Transmission of the univalents in the quasidiploidB. lineariloba cytodeme E was verified as being via the pollen, and not via the embryo sacs.The cytology ofBrachyscome lineariloba (Compositae, Asteroidae), 10.     

Phylogenetic analysis ofUlmaceae

A phylogenetic analysis of theUlmaceae, Cannabaceae, Barbeyaceae, andBroussonetia of theMoraceae produced nine equally parsimonious trees with 127 steps. TheUlmoideae (Ulmaceae, sensuGrudzinskaya) are a monophyletic group and distinct from theCeltidoideae. The genusAmpelocera occupies an isolated taxonomic position among the celtidoids. The similarity ofAmpelocera to the fossil celtidoid flowerEoceltis of North America suggests thatAmpelocera posesses an archaic suite of characters, and occupies a primitive position among the celtidoids, theCannabaceae and theMoraceae. The relationships among the other celtidoid taxa,Cannabaceae, andBroussonetia are problematic. TheCannabaceae andBroussonetia of theMoraceae are nested within the celtidoids suggesting that this is a paraphyletic group. The close, but unresolved, relationship of the celtidoids to theMoraceae andCannabaceae observed in this analysis, and the appearance of the celtidoids in the fossil record prior to the ulmoids suggests that the evolutionary relationship of the ulmoids and celtidoids may be more distant than current taxonomic treatments reflect.     

The phylogenetic relationships ofByblis andRoridula (Byblidaceae-Roridulaceae) inferred from partial 18S ribosomal RNA sequences

The phylogenetic relationships of the angiosperm generaByblis andRoridula have been the subject of ongoing taxonomic controversy. Twenty-eight taxa of varying degrees of alleged relationship, including 3 members of theWinteraceae (as an outgroup), were investigated using partial sequences of 18S rRNA (small subunit) and also compared against the morphological data set fromHufford's (1992) cladistic treatment of 80 members of theRosidae-Asteridae. The morphological analysis placed the two genera in a clade with theSarraceniaceae in theCorniflorae-Asterid group as a sister taxon to anEricales-Hydrangeales clade. The 18S rRNA analysis supports the recently publishedrbcL DNA analysis ofAlbert & al. (1992), withRoridula joined to taxa in the lowerRosidae, butByblis joining instead to members of theAsteridae near theSolanaceae. Comparisons for congruence between the three analyses placeByblis in the higher Asterid group near theSolanaceae, andRoridula possibly nearer theSarraceniaceae andEricales. These results imply that the traditional morphological characters used to relate the two genera are possibly the result of convergence towards similar ecological and life-history strategies rather than synapomorphies.     

The embryology ofStegnospermataceae,with a discussion on its status,affinities and systematic position

The embryology ofStegnosperma halimifolium andS. watsonii has been studied in detail. The tapetum is of the secretory type and its cells become multinucleate. Simultaneous cytokinesis in the pollen mother cells follows meiosis. The ripe pollen grains are 3-celled. The ovule is crassinucellate, bitegmic and amphitropous, with the micropyle formed by the inner integument alone. The female archesporium is one celled, and the parietal tissue 3–5 layered. The embryo sac development conforms to thePolygonum type. A central strand, 6 or 7 cells thick, differentiates inside the nucellus and extends from the base of the embryo sac to the chalazal region. The endosperm is nuclear. The embryogeny conforms to the Caryophyllad type. The seed coat is formed by the outer epidermis of the outer integument and the inner epidermis of the inner integument. Based on this evidence and other data, the status of the genus as an independent family,Stegnospermataceae (Stegnospermaceae) is confirmed. Apparently, it forms a connecting link betweenPhytolaccaceae andCaryophyllaceae.     

Hectorella: A member of the betalain-suborderChenopodiineae of the orderCentrospermae

Roots ofHectorella caespitosa Hook. f. were induced to produce a red pigment which was shown to be a betalain and not an anthocyanin. These data indicate thatHectorella belongs to theChenopodiineae, the betalain suborder of theCentrospermae, and excludes alignment with the anthocyanin family theCaryophyllaceae.     

Phylogeny of theAsterales sensu lato based onrbcL sequences with particular reference to theGoodeniaceae

TherbcL gene of 25 taxa was sequenced and analyzed cladistically in order to define more precisely the orderAsterales s.l. and to reconstruct the phylogeny ofGoodeniaceae. The cladistic analyses show that theAsterales comprise the familiesAbrophyllaceae, Alseuosmiaceae, Argophyllaceae, Asteraceae, Calyceraceae, Campanulaceae s.l.,Donatiaceae, Goodeniaceae (includingBrunoniaceae),Menyanthaceae, Pentaphragmataceae, andStylidiaceae. Abrophyllaceae, Alseuosmiaceae, Brunoniaceae, andDonatiaceae have previously not been studied in this respect. Within theGoodeniaceae, four groups supported by therbcL data can be distinguished: the genusLechenaultia, theAnthotium-Dampiera-group, the genusBrunonia, and a group formed by the remaining genera, theScaevola-Goodenia-group.     

Characterization of embryo globulins encoded by the maizeGlb genes

Two of the most abundant proteins in maize embryos are saline-soluble, water-insoluble globulins. One is aM _r 63,000 protein encoded by theGlbl gene and the other is aM _r 45,000 component encoded by theGlb2 gene. Both proteins accumulate to high levels during embryo development and are rapidly degraded during the early stages of seed germination. Amino acid composition analysis indicates that these proteins may serve as storage reserves to provide sources of nitrogen and carbon to the germinating embryo. Amino-terminal sequence analysis of the finalGlb1 gene product, GLB1, and its immediate precursor, GLB1′, indicates that the latter is proteolytically cleaved near the amino terminus to form GLB1. In addition to these biochemical studies, we describe the identification of a novel maize variant which lacks the protein product of theGlb2 gene. This contribution from the University of Illinois Agricultural Experiment Station was supported by grants from The Standard Oil Corporation, a wholly owned subsidiary of BP America, Inc., and the U.S. Department of Agriculture (No. 88-37262-3427).     

Further studies of the sieve-element plastids of theCaryophyllales includingBarbeuia,Corrigiola, Lyallia,Microtea, Sarcobatus,andTelephium

The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.     

The<Emphasis Type="Italic"> GAOLAOZHUANGREN2</Emphasis> gene is required for normal glucose response and development of<Emphasis Type="Italic"> Arabidopsis</Emphasis>

Recent studies of glucose (Glc) sensing and signaling have revealed that Glc acts as a critical signaling molecule in higher plants. Several Glc sensing-defective Arabidopsis mutants have been characterized in detail, and the corresponding genes encoding Glc-signaling proteins have been isolated. However, the full complexity of Glc signaling in higher plants is not yet fully understood. Here, we report the identification and characterization of a new Glc-insensitive mutant, gaolaozhuangren2 (glz2), which was isolated from transposon mutagenesis experiments in Arabidopsis. In addition to its insensitivity to Glc, the glz2 plant exhibits several developmental defects such as short stature with reduced apical dominance, short roots, small and dark-green leaves, late flowering and female sterility. Treatment with 4% Glc blocked expression of the OE33 gene in wild-type plants, whereas expression of this gene was unchanged in the glz2 mutant plants. Taken together, our results suggest that the GLZ2 gene is required for normal glucose response and development of Arabidopsis.Mingjie Chen and Xiaoxiang Xia contributed equally to this work.     

Ribosomal RNA sequence comparisons demonstrate an evolutionary relationship betweenZygnematales and charophytes

The nuclear-encoded small subunit ribosomal RNA (rRNA) sequences were determined forGenicularia spirotaenia, Mesotaenium caldariorum, andStaurastrum spec. (Zygnematales) to elucidate the evolutionary position of these green algae. Results of neighbour-joining and maximum parsimony phylogenetic analyses support a monophyletic origin of theZygnematales within the evolutionary assemblage defined by theCharophyceae (sensuMattox & Stewart) and land plants. TheZygnematales/Charophyceae/land plants are evolutionarily distinct from the monophyletic lineage defined by theChlorodendrales, Pseudoscourfieldiales, and theMicrothamniales/Chlorophyceae. In memoriamRobert W. Hoshaw.     

Insertion mutations at the maizeOpaque2 locus induced by transposable element familiesAc, En/Spm andBg

Eight independently isolated unstable alleles of theOpaque2 (O2) locus were analysed genetically and at the DNA level. The whole series of mutations was isolated from a maize strain carrying a wild-typeO2 allele and the transposable elementActivator (Ac) at thewx-m7 allele. Previous work with another unstable allele of the same series has shown that it was indeed caused by the insertion of anAc element. Unexpectedly, the remaining eight mutations were not caused by the designatedAc element, but by other insertions that are structurally similar or identical to one of two different autonomous transposable elements. Six mutations were caused by the insertion of a transposable element of theEnhancer/Suppressor-Mutator (En/Spm) family. Two mutations were the result of the insertion of a transposable element of theBergamo (Bg) family. Genetic tests carried out with plants carrying the unstable mutations demonstrated that all were caused by the insertion of an autonomous transposable element.     

Molecular analysis of theBg-rbg transposable element system ofZea mays L.

Summary The two components of theBg-rbg transposable element system of maize have been cloned. TheBg element, isolated from the mutable allelewx-m32 :: Bg is inserted in the intron of theWaxy (Wx) gene between exons 12 and 13. The length of the element is of 4869 bp.Bg has 5 by terminal inverted repeats, and generates upon insertion an 8 by direct duplication of the target sequence. Both ends of theBg element contain a 76 by direct repeat adjacent to the terminal inverted repeats. The hexamer motif TATCG_kC ^G is here repeated several times in direct or inverse orientation. Therbg element was isolated from the mutable alleleo2m(r) where it is located in the promoter region of theOpaque-2 (O2) gene.rbg is approximately 4.5 kb in length, has terminal inverted repeats identical to those of theBg element, and is also flanked by an 8 by direct duplication at the target site. LikeBg, rbg carries the 76 by direct repeats. Restriction enzyme analysis reveals that, compared toBg, the receptor element is distinguishable by small deletion and insertion events. Sequence data indicate that not more than 75% homology exists at the DNA level between therbg element and the autonomousBg element.     

Relationships, circumscription, and biogeography of Arcytophyllum (Rubiaceae) based on evidence from cpDNA

A cladistic analysis was performed using nucleotide sequence variation in therps16 intron and thetrmL-F region (plastid DNA).Arcytophyllum belongs in a subclade of the tribe Spermacoceae (s.l.) together with the American species presently classified in the generaHedyotis andHoustonia. This subclade is morphologically characterized by cymbiform seeds.Arcytophyllum is the sister group of all AmericanHedyotis andHoustonia and it is suggeste that these latter would be most conveniently treated as a single genus, the correct name of which would beHoustonia.Arcytophyllum should be circumscribed such that it excludesA. serpyllaceum, which is not a member of theArcytophyllum-Houstonia clade but more closely related toBouvardia. The phylogeny that was reconstructed suggests that the ancestral area of theArcytophyllum-Houstonia clade is the South American tectonic plate.     

Serologische Untersuchungen zur Gliederung derBrassicaceae

The serological investigations support the opinion ofJanchen (1942) to combine the generaBunias, Isatis, andSisymbrium in the tribeSisymbrieae; Cheiranthus, Erysimum, andMatthiola in the tribeHesperideae; andBrassica, Crambe, Sinapis, andSuccowia in the tribeBrassiceae. They further underline the central position of theSisymbrieae and the isolated position of theHeliophileae. In accordance withEigner (1973) theBrassiceae are placed closer to theSisymbrieae than inJanchen; the same holds for thePringleeae. No serological justification could be found to uniteArabis andBarbarea in the tribeArabideae, andAlyssum andLunaria in theAlysseae. From the antigen-systems used among the representatives ofJanchen's Lepidieae the generaLepidium andNeslia show remarkable correspondence both toCamelina andThlaspi, but not toCochlearia which appears distant fromCamelina andThlaspi also.

Teil 1/Part 1.     

Heliantheae sensu lato (Asteraceae), clades and classification

The interrelationships within theHeliantheae s. lato and the closely relatedEupatorieae are analyzed and discussed. The basis to this discussion is a cladistic analysis of 141 morphological characters (172 apomorphic states) scored for 97 genera. TheHeleniae s. lato, a subgroup of theHeliantheae s. lato, are paraphyletic, and a monophyletic group corresponding largely to theHeliantheae s. str. is recognized. TheEcliptinae sensuRobinson are polyphyletic. TheCoreopsidinae form an ingroup in theHeliantheae s. str. TheTageteae (Pectidinae) and theMadieae (Madiinae) are two separate branches within the helenioid assemblage of taxa.