Testis-specific β2 tubulins are identical in Drosophila melanogaster and D. hydei but differ from the ubiquitous β1 tubulin

In Drosophila as in many organisms tubulins are encoded by a gene family. We have determined the complete nucleotide sequences coding for the 1 and 2 tubulins of Drosophila melanogaster and the 2 tubulin of D. hydei, and found these insect tubulins to be highly conserved and like tubulins of other organisms. This is discussed with reference to the possible functional domains of these proteins. — The 1 tubulin gene of Drosophila is constitutively expressed, whereas the 2 tubulin is expressed specifically in the testes. In D. melanogaster the amino acid sequences of these proteins are 95% homologous, differing at only 25 positions. In the testes the 2 tubulin participates in different microtubules as shown by genetic analysis (Kemphues et al. 1982). Interestingly, all of the amino acids characteristic of the testis-specific 2 tubulin are also present in the corresponding gene of D. hydei. Of special interest is the high degree of conservation of the carboxy-terminal domain in these functionally equivalent tubulins.     

Evolution of thedec-1 eggshell locus inDrosophila. I. Restriction site mapping and limited sequence comparison in themelanogaster species subgroup

Summary We have analyzed 18 kb of DNA in and upstream of thedefective chorion-1 (dec-1) locus of the eight known species of themelanogaster species subgroup ofDrosophila. The restriction maps ofD. simulans, D. mauritiana, D. sechellia, D. erecta, andD. orena are shown to have basically the restriction map ofD. melanogaster, whereas the maps ofD. teissieri andD. yakuba were more difficult to align. However, the basic amount of DNA and sequence arrangement appear to have been conserved in these species. A small deletion of varying length (65–200 bp) is found in a repeated sequence of the central transcribed region ofD. melanogaster, D. simulans, andD. erecta. Restriction site mapping indicated that thedec-1 gene is highly conserved in themelanogaster species subgroup. However, sequence comparison revealed that the amount of nucleotide and amino acid substitution in the repeated region is much larger than in the 5 translated region. The 5 flanking region showed noticeable restriction site polymorphisms between species. Based on calculations from the restriction maps a dendrogram was derived that supports earlier published phylogenetic relationships within themelanogaster species subgroup except that theerecta-orena pair is placed closer to themelanogaster complex than toD. teissieri andD. yakuba.     

Genetic Linkage Maps of the Guppy (Poecilia reticulata): Assignment of RAPD Markers to Multipoint Linkage Groups

Genetic linkage maps of the guppy (Poecilia reticulata) were constructed from independent crosses between the Tuxedo strain and a feral line (Wildtype). Segregation patterns of random amplified polymorphic DNA (RAPD) markers and phenotypic markers were investigated in F₂ offspring of Tuxedo × Wildtype and Wildtype × Tuxedo crosses. Among the 300 and 276 RAPD markers scored for the respective crosses, linkages were identified for 230 and 212, respectively. The Tuxedo × Wildtype and Wildtype × Tuxedo maps spanned 2100 Kosambi centiMorgans (cM_K) and 1900 cM_K, respectively, in 28 linkage groups. Average marker resolution was 10 cM_K. Genome length was estimated at 4410 cM_K and 4060 cM_K for the respective crosses, with an average physical distance of 166 kbp/cM_K. Several RAPD markers were closely linked to or mapped onto the loci for the sex-determining region (SdR), and the sex-linked black caudal-peduncle (Bcp) and red tail (Rdt) genes. These primary linkage maps are the initial step toward the construction of a composite high-density map to facilitate map-based cloning and marker-assisted selection of quantitative trait loci that are essential for the development of comprehensive breeding programs for the guppy.     

über die biologie blutsaugender simuliiden (diptera) I. Besamungsrate der ♀♀ beim blütenbesuch und anflug auf den blutwirt

Zusammenfassung Außer an ihren Blutwirten findet man die bei uns heimischen Simuliiden regelmäßig im Frühjahr auf der Weißweide (Salix alba), im Sommer auf den gelbgrünen Blüten und Früchten des Pastinak (Pastinca sativa) und im Herbst auf den grünen Blüten des Efeu (Hedera helix). Die Blüten zumindest von Pastinak und Efeu werden von allen Simuliidenarten selektiv angeflogen. Die übrigen Umbelliferen bleiben, auch wenn sie in unmittelbarer Nähe von Pastinak wachsen, unberührt. Efeu wird auch dann reichlich angeflogen, wenn er in einzelnen Stöcken an entlegenen Plätzen wächst. Alle von Simuhiden nachweislich direkt angeflogenen Blüten haben eine in der Natur unauffällige, entweder gelbe, gelbgrüne oder rein grüne Farbe und offene Nektarien. Aus diesen Gründen scheint mindestens beim Anflug auf Efeu und Pastinak eine olfaktorisch gesteuerte Orientierung vorzuliegen. Sie ist offenbar viel spezifischer als die vorwiegend optische Orientierung derselben Simuliidenarten nach ihren Blutwirten.Durchschnittlich sind etwa doppelt soviele wie auf Blüten anzutreffen. Abends und nachts sowie an kalten, regnerischen Tagen findet man mehr Simuliiden auf Pastinak als an sonnigen Tagen. Die auf Blüten angetroffenen der mammalophilen Simuliidenarten Wilhelmia salopiensis, W. equina, Boophthora erythrocephala und Odagmia ornata sind durchschnittlich zu 90% besamt, die der ornithophilen Art Eusimulium latipes nur zu 32%. Bei allen Arten fanden sich auf Blüten stets auch einige mit Blut im Mitteldarm oder legereifen Eiern im Abdomen. Der Blütenbesuch kann demnach vor und nach dem Blutsaugen stattfinden.Beim Anflug auf den Blutwirt sind die der genannten mammalophilen Arten ebenfalls zu rund 98% besamt, die von E. latipes wiederum nur zu 53%. Das Verhalten dieser Art, welche auch nachts Blut saugt, scheint von dem der mammalophilen Arten hinsichtlich der Geschlechterfindung erheblich abzuweichen.Das bekannte tagesperiodische Anflugsverhalten der auf ihren Säugetierblutwirt mit je einem Maximum nach Sonnenaufgang und vor Sonnenuntergang läßt sich auch bei den zugehörigen feststellen, wean man berücksichtigt, daß die den Blutwirt nicht direkt anfliegen, sondern ihn nur umschwärmen.Das Anflugsverhalten der und ist von der Änderung der Lichtintensität in der Zeiteinheit (Wolfe u. Peterson 1960), das Schwarmverhalten der allein von der absoluten Tageshelligkeit (Wenk 1965b) abhängig. Die Kopulation kann demnach einerseits morgens und abends in der Nähe des Blutwirtes und andererseits tagsüber beim Schwärmen der stafffinden. Wie wir später direkt zeigen konnten, sind beide Arten der Geschlechterfindung zur Kopulation bei drei von den vier genannten mammalophilen Simuliidenarten verwirklicht (Wenk 1965b). Die Kopulation von O. ornata und der ornithophilen Art E. latipes konnten wir dagegen selbst nie beobachten.

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Summary Simuliids of South-Western Germany show a marked preference for the white willow (Salix alba) in spring, the yellow blossoms of parsnip (Pastinaca sativa) in summer, and the green blossoms of ivy (Hedera helix) in autumn, whereas all the other Umbelliferae are disregarded, although they may be numerous and in close proximity. Ivy will be found by many simuliids even if growing in single plants at hidden places. All flowers for which a predelection by simuliids can be clearly established are inconspicuous under natural conditions — being of yellow, yellowish green or pure green colour — and their nectaries are of the open type. Therefore orientation of these simuliids to their nectar donors seems to rely on olfactoric senses and is apparantly much more specific than optical orientation to the blood hosts of the same species.On average, about twice as many are found on blossoms than During the evening and night; as well as on cold rainy days, more simuliids are encountered on parsnip than on sunny days. The of the mammalophilic species Wilhelmia salopiensis, W. equina, Boophthora erythrocephala and Odagmia ornata are inseminated at the rate of 90% , the of the ornithophilic species Eusimulium latipes at 32% only. In all species, some have been found with blood in the midgut or eggs in the abdomen, i. e. visiting of flowers may take place before or after bloodsucking.All of mammalophilic species attacking their blood hosts are inseminated at the rate of 98%, the of the ornithophilic species E. latipes at 53% only. The behaviour of the latter, which is bloodsucking also at nighttime, seems to differ considerably with regard to sexfinding orientation from the mammalophilic species.The diurnal periodicity of mammalophilic in attacking the host —with the well-known maxima at sunrise and sunset — is the same for the , bearing in mind that do not attack the hosts of their directly but are flying around them. Consequently, copulation may take place either in the morning and evening near the blood host, or during the day in the swarms of . It has been demonstrated for three of the four mammalophilic species mentioned (WENK, 1965b) that sex-finding and copulation occur at both occasions.

     

Die Laut?u?erungen des Blutspechts,Dendrocopos syriacus

Zusammenfassung Blutspechtlaute sind den Lauten der Buntspechte ähnlich, aber doch deutlich anders.Paarkontakt: Auffallend ist der Unterschied zwischen - und -Wirbeln: -Wirbel 27,5 Schläge (37 Wirbel), -Wirbel 18,0 Schläge (6 Wirbel). Die Wirbel, vor allem die -Wirbel, sind deutlich länger als die Trommelwirbel vom Buntspecht. Zwischen dem 1. und 2. Schlag ist ein großer Abstand. Die Schlagfolge nimmt von Wirbelbeginn bis zu Wirbelende zu.Gurrende Laute sind bei der Ablösung und Kopula zu hören. Sie klingen ähnlich wie die entsprechenden Buntspechtlaute. Das gegenseitige Verstehen dieser Laute dürfte — falls es Bastard-Paare geben sollte — sehr wichtig sein (Paar-Synchronisation).Feindsituation: Die aggressiven Kreck-Laute tönen deutlich anders als die vom Buntspecht. Sie scheinen dem Kreck des Weißrückenspechts zu ähneln. Das gellende Schirken bei großer Gefahr besteht aus einzelnen Elementen, deren Lautgestalt einem umgekehrten Kix ähnlich ist.Unspezifische Erregung: Die Bedeutung des Kixens ist nicht festgelegt. Kixen kann man das ganze Jahr hindurch hören. Blutspechtkixen klingt weicher als das Kixen des Buntspechts. Die Tonhöhe hängt von der Erregung des Vogels ab.Güg-Reihen hörte ich von erregten Vögeln während der Ausflugphase der Jungen oder bei Störungen während des Brütens. Buntspechte haben keine entsprechende Lautreihe.

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Summary The vocalisation of Syrian Woodpecker is similar to that of the Great Spotted Woodpecker. But nevertheless the differences are striking.Pair-contact: In drumming there is an apparent difference between and : -drumming 27,5 strokes (37 drummings), -drumming 18,0 strokes (6 drummings). The drumming especially that of the differs significant from that ofmajor. Between the first and second stroke there is a wide distance. The frequence of strokes gradually increases. By changing at the nest (in relief ritual) and at copula gurr sounds are uttered (contact notes,Lawrence). They are similar to those ofmajor. Reciprocous understanding of this sounds would be very necessary, if there are hybrid-pairs (Pair-synchronisation).Aggressive notes: The aggressive Krek-sounds are apparently unlike those ofmajor. They seem to be similar to those ofD. leucotos. Shrilling sounds of alert consist in elements which in the spectrograms are similar to the figure of a Kix, upside down.Unspecific notes: The meaning of Kixen is not fixed. Kixen is to be heard throughout the year. The level of sound is in dependence to excitement.Series of Güg-notes are uttered by Syrian woodpeckers in great excitement, when the young leave the nest by the young or when the adults are disturbed in incubating.D. major has no corresponding vocalisation.

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Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

The β heterochromatic sequences flanking the I elements are themselves defective transposable elements

Phylogenetic studies suggest that mobile element families are unstable components of the Drosophila genome. Two examples of immobilization of a transposable element family are presented here: as judged by their constant genomic organization among unrelated strains, the F and I element families have been respectively immobilized for a long time in D. simulans and in the reactive D. melanogaster strains (these are the laboratory strains which escaped the recent I invasion of D. melanogaster natural populations). All the elements of these defective families are located in the heterochromatic portion of the genome. Moreover, most if not all of the heterochromatic sequences into which the defective I elements are embedded are themselves non-mobile members of various nomadic families such as mdg 4, 297, 1731, F and Doc. These results are discussed with special emphasis on the possible nomadic origin of heterochromatin components and on the mechanisms of evolutionary turnover of the transposable element families.     

O-Glycosylhydrolases of Marine Filamentous Fungi: β-1,3-Glucanases of Trichoderma aureviride

The ability to produce extracellular O-glycosylhydrolases was studied in 14 strains of marine filamentous fungi sampled from the bottom sediments of the South China Sea. The following activities were detected in the culture liquids of the fungi: N-acetyl--D-glucosaminidase, -D-glucosidase, -D-galactosidase, -1,3-glucanase, amylase, and pustulanase. -1,3-Glucanases were isolated by ultrafiltration, hydrophobic interaction chromatography, and ion exchange chromatography, and their properties were studied. Data on products of enzymatic digestion of laminaran, absence of transglycosylation activity, and the pattern of action of natural inhibitors confirmed that -1,3-glucanase belonged to the exo type. Inhibitor analysis demonstrated the role of a thiol group and tryptophan and tyrosine residues in the catalytic activity.     

A coupled pacemaker-slave model for the insect photoperiodic clock: interpretation of ovarian diapause data in Drosophila melanogaster

A coupled circadian oscillator model for the insect photoperiodic clock is described which consists of a hierarchically arranged pacemaker and slave. The pacemaker is self-sustained, temperature compensated, and entrainable by the light cycle; the slave is a damping oscillation receiving entrainment from two sources, from the pacemaker via a coupling factor, and also directly from the light. The damping slave oscillation is seen as the photoperiodic oscillator, equivalent to that proposed earlier by Lewis and Saunders (1987). The present simulations describe the effect of the strength of the coupling factor between hypothetical short- and long-period pacemaker oscillations (modelled on the clock mutants per ^sand per ^L2in Drosophila melanogaster) and a slave oscillation with a period of about 24 hours. The output is presented in terms of photoperiodic response curves and Nanda-Hamner, or resonance, plots. With a high coupling strength, the pacemakers strongly entrain the slave, but with a low coupling strength the slave's properties are more evident. The model is presented as a possible explanation for recent ovarian diapause data in D. melanogaster clock mutants (Saunders 1990), but also as a more general model for the role of the insect circadian system in seasonal time measurement.     

Yeast ribosomal proteins

Summary Homology maps between bacteriophages 81, 80 and were constructed on the basis of electron microscope observation of DNA heteroduplexes. In 81/80 heteroduplex, the left half and the right terminal region of 13% the total molecular length were highly homologous, while the remaining region covering the early gene cluster was entirely nonhomologous. In 81/ heteroduplex, high-degree homologies were detected at the left 14% terminal region covering the head gene cluster, the central 3.8% region covering the att-int-xis region and the 1.3% Q homology region. Low-degree homologies of shorter length were scattered at the tail gene cluster, b2 region, cIII region, PQ region and SR region. Comparing our results with the homology maps of other lambdoid phages reported by Simon et al. (1971) and Fiandt et al. (1971), a phylogenic relation of 81 to other lambdoid phages and the role of recombination in the course of divergence of lambdoid phages are discussed.     

Patterns of puffing activity in the salivary gland chromosomes of Drosophila

Exposure of Drosophila melanogaster larvae to high temperature for short periods of time results in marked changes in the puffing patterns of salivary gland chromosomes. Temperature shock induces puffing at 9 specific loci; this pattern of induced puffs shows little developmental specificity and is similar in three strains of D. melanogaster (including the mutant lethal giant-larvae) and in D. simulans. Temperature shock also (i) retards the regression of some developmentally specific puffs and (ii) results in the regression of all other puffs normal to development. The effect of temperature treatment is similar in vivo and after in vitro treatment of salivary glands. The in vitro response is not sensitive to cycloheximide. A similar pattern of induced puffs to that found after temperature treatment is found during recovery of larvae from anoxia, but additional puffs are induced after anoxia. The size and duration of activity of the induced puffs is dependent upon the magnitude of the treatment.     

Investigations on the organization of genetic loci in Drosophila melanogaster: lethal mutations affecting 6-phosphogluconate dehydrogenase and their suppression.

Summary The molecular nature of lethal and semilethal mutations in the Pgd locus of D. melanogaster coding for 6-phosphogluconate dehydrogenase (6PGD) was studied. All the 11 mutations affect the structural gene of the Pgd locus: 3 semilethal mutations resulted in altered 6PGD molecules with decreased catalytic activities; the rest 8 lethals were null alleles characterized by mutant polypeptides capable of reacting with antisera against highly purified 6PGD.Null or low activity alleles for glucose-6-phosphate dehydrogenase induced by ethyl methanesulfonate were shown to be suppressors for the lethal mutations in the Pgd locus.A monocistronic type of organization of the Pgd locus is suggested taking into account the biochemical mechanism of suppression of the Pgd-lethals and their location in the structural gene coding for 6PGD.     

Karyotypes and sex determination in two species of laelapid mites (Acari: Gamasida)

The chromosome number and morphology of two species of the family Laelapidae have been determined: Hypoaspis aculeifer Canestrini, 1887 has 9() and 18() chromosomes and Cosmolaelaps miles Berlese, 1914 7() and 14(). Both karyotypes have monokinetic chromosomes and show obvious similarity. The longest chromosome of both species consists of a normal and a heterochromatic arm. The two laelapid mites prove to be arrhenotokous, as unfertilized females lay eggs from which only males arise. A theory has been postulated that within the Gamasida an evolutionary line towards arrhenotoky is present.Arguments supporting an independent evolution of sex determining system in the two acarine taxa Actinotrichida and Anactinotrichida are discussed.     

Polytene chromosome structure at the submicroscopic level

Nuclear DNA obtained by SDS treatment or phenol extraction of isolated polytene salivary gland nuclei of D. melanogaster and D. hydei was investigated electron-microscopically. All preparations contained only linear doublestranded DNA filaments of various length. The mean length of a sample of 52 DNA filaments of D. melanogaster produced by SDS treatment was 37.3 . For D. hydei a mean length of 24.2 was established on account of a sample of 51 filaments obtained by SDS treatment. In samples obtained by phenol extraction a mean length of 23.8 (26 filaments) was found. Pronase digestion following SDS treatment gave a mean length of 29.1 for D. melanogaster (46 filaments) and of 17.1 for D. hydei (57 filaments). — The mean length of DNA filaments from D. hydei sperm was 21.5 on the basis of 25 filaments measured. The length distribution of the DNA of the samples of filaments measured varied. Preparations of single-stranded DNA obtained by heat denaturation of samples of D. hydei nuclear DNA revealed very long filaments. An obvious increase in the number of filaments shorter than 30 as compared with double-stranded DNA could not be established.     

Reproduktionsbiologische Untersuchungen an dreiLittorina-Arten der südlichen Nordsee

Populations ofLittorina mariae, L. obtusata andL. saxatilis from the coast near Roscoff (Brittany), from the North Sea islands Helgoland and Sylt were investigated with regard to several characters of their reproductive biology. Important factors are body size and weight, maturation size, shell thickness, sex ratio and reproductive effort of adults as well as number, size and mortality of embryos. MatureL. saxatilis individuals inhabiting sandy shores are smaller and have thinner shells and higher reproductive effort than those on rocky coasts. On shores with loose and semipermanent boulders the adults are clearly larger. Interannual variations in some life history parameters may be explained by changes in food supply. In populations with small adults, are bigger than . In localities whereL. mariae andL. obtusata occur sympatrically, a tendency to accentuate interspecific contrast is recognized. Life history patterns, especially inL. saxatilis populations, show two tendencies: (a) a rapid increase of shell-size and thickness, which offers better chances of survival and of maximizing clutch-size and clutch-numbers during life-time; (b) early entrance into maturity leads to accelerated reproduction, but life expectation is reduced. Both tendencies are balanced by the action of biotic and abiotic factors.     

Characterization of the effectors required for stable inheritance of Streptococcus pyogenes pSM19035-derived plasmids in Bacillus subtilis

The low-copy-number and broad-host-range pSM19035-derived plasmid pBT233 is stably inherited in Bacillus subtilis cells. Two distinct regions, segA and segB, enhance the segregational stability of the plasmid. Both regions function in a replicon-independent manner. The maximization of random plasmid segregation is accomplished by the recombination proficiency of the host or the presence of the pBT233 segA region. The segA region contains two open reading frames (or) [ and ]. Inactivation or deletion of or results in SegA^– plasmids. Better than random segregation requires an active segB region. The segB region contains two ors (or and or). Inactivation of either of the orfs does not lead to an increase in cell death, but or^– plasmids are randomly segregated. These results suggest that pBT233 stabilization relies on a complex system involving resolution of plasmid oligomers (segA) and on the function(s) encoded by the segB region.     

Genetics of the sex ratio anomaly in Drosophila hybrids of the Virilis group

Summary A study was made of the effect of genotype and temperature (25 and 17°C) on sex ratio in the hybrids D. virilis Sturt. X D. littoralis Sokolov. A genetic system has been found controlling sex-differential viability. In the F₁ of the reciprocal hybrids D. virilis X D. littoralis the sex ratio is normal, though at 17°C females are slightly excessive. The abnormal sex ratio is observed only in the progeny of test crosses.The major gene causing the death of female progeny of the cross [ (, D. virilis x , D. littoralis) x D. virilis] x D. littoralis is located on chromosome 2 of D. virilis. It is expressed as a lethal if chromosome 5 is heterogeneous virilis-littoralis. Chromosome 3 of D. virilis bears a modifier-enhancer and chromosome 5, a suppressor, of this lethal found in chromosome 2. This genetic system has a maternal effect and functions at 25°C, interacting with the X-chromosome of D. littoralis. If the maintainance temperature is lowered to 17°C, the progeny of the cross hybrid FB₁ x D. littoralis is predominantly female. Partial death of males is accounted for by a disturbance in the interaction between the genes of X-chromosome in certain combinations with the D. virilis autosomes and the Y-chromosome of the paternal species D. littoralis.Sex-differential mortality in the hybrids D. virilis x D. littoralis is one of the isolating factors between these species which does not appear to act until the second and subsequent F₁ generations due to the formation of the recombination load.     

Infloreszenz- und Blütenentwicklung bei der KugeldistelEchinops exaltatus (Asteraceae)

InEchinops the flowers are surrounded by several scales and initiated in an acropetal and spiral succession on a cone-like inflorescence axis (Figs. 1–6). The floral organs originate in the following sequence: petals—stamens—carpels—pappus. The petals arise from a meristematic rim and therefore are already interconnected when they arise as primordia. This sympetalous zone remains rather inconspicuous for a long period, but eventually, the elongated corolla tube is formed through intercalary growth in a ring zone. Thereby, the stamens are moved upwards and form ledges on the corolla tube (Fig. 34). In the inferior ovary the usual zones of the typical angiospermous gynoecium can be distinguished, namely a synascidiate, symplicate and hemisymplicate zone. The ovule is borne on carpellary tissue.

     

Synthesis of Aminoethyl Glycosides of the Ganglioside GM1 and Asialo-GM1 Oligosaccharide Chains

4-O-Glycosylation of 2-azidoethyl 2,3,6-tri-O-benzyl-4-O-(2,3-di-O-benzyl-6-O-benzoyl--D-galactopyranosyl)--D-glucopyranoside with a disaccharide donor, 4-trichloroacetamidophenyl 4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl--D-galactopyranosyl)-1-thio-2-trichloroacetamido--D-galactopyranoside, in dichloromethane in the presence of N-iodosuccinimide and trifluoromethanesulfonic acid resulted in a tetrasaccharide, 2-azidoethyl (2,3,4,6-tetra-O-acetyl--D-galactopyranosyl)-(1 3)-(4,6-di-O-acetyl-2-deoxy-2-trichloroacetamido--D-galactopyranosyl)-(1 4)-(2,3-di-O-benzyl-6-O-benzoyl--D-galactopyranosyl)-(1 4)-2,3,6-tri-O-benzyl--D-glucopyranoside, in 69% yield. The complete removal of O-protecting groups in the tetrasaccharide, the replacement of N-trichloroacetyl by N-acetyl group, and the reduction of the aglycone azide group to amine led to the target aminoethyl glycoside of -D-Gal-(1 3)--D-GalNAc-(1 4)--D-Gal-(1 4)--D-Glc-OCH₂CH₂NH₂ containing the oligosaccharide chain of asialo-GM₁ ganglioside in 72% overall yield. Selective 3-O-glycosylation of 2-azidoethyl 2,3,6-tri-O-benzyl-4-O-(2,6-di-O-benzyl--D-galactopyranosyl)--D-glucopyranoside with thioglycoside methyl (ethyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero--D-galacto-2-nonulopyranosyl)oate in acetonitrile in the presence of N-iodosuccinimide and trifluoromethanesulfonic acid afforded 2-azidoethyl [methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero--D-galacto-2-nonulopyranosyl)oate]-(2 3)-(2,6-di-O-benzyl--D-galactopyranosyl)-(1 4)-2,3,6-tri-O-benzyl--D-glucopyranoside, the selectively protected derivative of the oligosaccharide chain of GM₃ ganglioside, in 79% yield. Its 4-O-glycosylation with a disaccharide glycosyl donor, (4-trichloroacetophenyl-4,6-di-O-acetyl-2-deoxy-3-O-(2,3,4,6-tetra-O-acetyl--D-galactopyranosyl) 1-thio-2-trichloroacetamido--D-galactopyranoside in dichloromethane in the presence of N-iodosuccinimide and trifluoromethanesulfonic acid gave 2-azidoethyl (2,3,4,6-tetra-O-acetyl--D-galactopyranosyl)-(1 3)-(4,6-di-O-acetyl-2-deoxy-2-trichloroacetamido--D-galactopyranosyl)-(1 4)-{[methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero--D-galacto-2-nonulopyranosyl)onate]-(2 3)}-(2,6-di-O-benzyl--D-galactopyranosyl)-(1 4)-2,3,6-tri-O-benzyl--D-glucopyranoside in 85% yield. The resulting pentasaccharide was O-deprotected, its N-trichloroacetyl group was replaced by N-acetyl group, and the aglycone azide group was reduced to afford in 85% overall yield aminoethyl glycoside of -D-Gal-(1 3)--D-GalNAc-(1 4)-[-D-Neu5Ac-(2 3)]--D-Gal-(1 4)--D-Glc-OCH₂CH₂NH₂ containing the oligosaccharide chain of GM₁ ganglioside.     

Transmission of plastids by pollen in Antirrhinum majus

Summary Up to now Antirrhinum was classified as a typical example for a uniparentalmaternal inheritance of the plastids. However, the findings reported here prove that also the male gametophyte of Antirrhinum may occasionally transmit plastids into the egg. This conclusion is based on genetic experiments involving a form of the plastom mutant prasinizans which is described as gelbgrüne prasinizans. In contrast to all other plastid mutations known in Antirrhinum majus this mutant originated in Sippe 50 is completely viable. In plants containing plastids of this mutant type only, the mutant character is manifested during early growth stages. Cotyledons and first foliage leaves which are initially white or white yellow, slowly turn green and become indistinguishable from normal Sippe 50. Reciprocal crosses of green Sippe 50 with gelbgrüne prasinizans gave few variegated descendants; the others were exclusively plants identical with the maternal parent as far as leaf colour is concerned (Table). The variegated individuals cannot be gene mutants since selfing and crossing experiments showed non-mendelian inheritance. Furthermore it could be ruled out that in the cross Sippe 50 x gelbgrüne prasinizans the three variegated descendants represent spontaneous new plastom mutants because the pale tissue in these plants turned green in the same way as the paternal parent. Because of the typical greening of this mutant and since plastid mutations could be ruled out we have to conclude that plastids were transmitted by the pollen parent into the egg. There these plastids multiplied together with the maternal plastids giving rise to the chimeras after sorting-out of the two plastid types. This interpretation is supported by the observation of mixed cells in tissues where the leaf variegation is finely mosaiced. The results were possible only because the plastids of the pollen parent can be unequivocally recognised.     

Nucleotide sequence comparison of the Adh gene in three drosophilids

Summary The alcohol dehydrogenase (Adh) gene has been isolated fromDrosophila simulans andD. mauritiana by screening clone libraries of each with a previously cloned Adh gene fromD. melanogaster. The isolated clones were subcloned and partially sequenced to determine the relatedness of these species and to examine details of evolutionary change in the structure of the Adh gene. We report the sequence of the first 704 nucleotides of each gene as well as 127 bases in the 5 untranslated region. When these sequences are compared,D. melanogaster differs fromD. simulans andD. mauritiana by 2.8% and 3.1%, respectively.D. simulans andD. mauritiana differ by only 1.8%, implying that they are more closely related to each other than either is toD. melanogaster. This is consistent with phylogenetic relationships established by a variety of genetic, biochemical, and morphological means and illustrates that DNA sequencing of a single gene may be used to assess the evolutionary relationships of species.