The grassland communities of the southeastern basin of the Labe river 2. Synecology

This part of the study, referring to the previous syntaxonomic part (Ková? 1981), presents the results of a synecological examination of nine grassland communities of the Labe river basin covering roughly the following gradient of the alluvial hydrosere: theCerastio arvensi-Festucetum trachyphyllae trifolietosum pratensis, theArrhenatheretum elatioris typicum, theAlopecuretum pratensis, theStellario-Deschampsietum caespitosae phalaridetosum, theSerratulo-Festucetum commutatae, theMolinietum coeruleae brometosum, theAngelico-Cirsietum oleracei, theCaricetum gracilis typicum, theCaricetum buekii. The long-term study of ground-water level fluctuations showed their close connection to other characteristics of the meadow soils (soil type, moisture content, granulometric composition, capillary water-holding capacity, porosity, acidity, mineral nutrient contents, microbial activity, soil temperature) as well as to the development and distribution of the grassland communities associated with ecosystems of river alluvia. The formation and dynamics of the vegetation in the large river floodplain (at present exposed to the impact of far-reaching hydrological alteration) are explained as a consequence of changes in the natural ecocycles supporting the long-term stable character of the large river basin within the landscape.     

Salix silesiaca communities in the Fatra Mts. (Central Slovakia)

Two new associations belonging to theSalicion silesiacae within theBetulo carpaticae-Alnetea viridis are described. These are disclimax shrub communities dominated bySalix silesiaca at higher altitudes of the Fatra Mts. (Western Carpathians). Synmorphological, synecological, syntaxonomical, syngenetical and synchorological characteristics of the communities are given. Floristic differences between the montane shrub communities in the Western Carpathians and those in the Sudeten Mts. are summarized in a synthetic table.     

ThegrpD55 locus ofEscherichia coli appears to be an allele ofdnaB

Attempts to characterize thegrpD55 mutation ofEscherichia coli have led us to conclude that the gene had been assigned an incorrect map position. The mutation was found to cotransduce withmalF3089:: Tn10 (at ～91.5 min) and adnaB-expressing plasmid was able to complement fully thegrpD55 defect in λ replication. These studies strongly suggest thatgrpD55 is an allele ofdnaB and is localized near 92 min on theE. coli linkage map.     

Characterization of thelet-653 gene inCaenorhabditis elegans

A mutation in thelet-653 gene ofCaenorhabditis elegans results in larval death. The lethal arrest is concurrent with the appearance of a vacuole anterior to the lower pharyngeal bulb. The position of the vacuole is consistent with a dysfunction of the secretory/excretory apparatus. Germline transformation rescue experiments were able to position thelet-653 gene to two overlapping cosmid subclones. Sequence data generated from both cDNA and genomic DNA subclones indicated thatlet-653 encodes a mucin-like protein. Our characterization suggests that a mucin-like protein is essential for effective functioning of the secretory/excretory apparatus withinC. elegans.     

Vegetation on anthropogenic metalliferous soils in the Eastern Alps

A syntaxonomic revision of vegetation of anthropogenic metalliferous habitats (mine spoils of lead, zinc and copper mining) in the Eastern Alps (Austria, Germany, Italy and Slovenia) was made. The communities studied belong to theThlaspietea rotundifolii (Linaria alpina-Cerastium uniflorum comm.,Papaveri kerneri-Thlaspietum kerneri, Violetum dubyanae, Thlaspietum cepaeifolii, Thlaspietum rotundifolii, Scrophulario juratensis-Erysimetum sylvestris, Minuartia gerardii-Silene glareosa comm.,Epipactido atrorubentis-Silenetum glareosae andSileno alpestris-Moehringietum muscosae) and to theAsplenietea trichomanis (Sileno rupestris-Asplenietum). There is neither floristic support nor syntaxonomic justification for the concepts of theGalio anisophylli-Minuartion vernae, theVioletalia calaminariae and theVioletea calaminariae in the Eastern Alps. These units should be included within theThlaspion rotundifolii, Thlaspietalia rotundifolii andThlaspietea rotundifolii, respectively.     

An eye imaginal disc-specific transcriptional enhancer in the long terminal repeat of thetom retrotransposon is responsible for eye morphology mutations ofDrosophila ananassae

Optic morphology (Om) mutations ofDrosophila ananassae are semidominant, neomorphic and nonpleiotropic, map to at least 22 loci scattered throughout the genome, and are associated with the insertion of thetom retrotransposon. Molecular and genetic analyses have revealed that eye morphology defects ofOm mutants are caused by the ectopic or excessive expression ofOm genes in the eye imaginal discs of third instar larvae. It is therefore assumed that thetom element carries tissue-specific gene regulatory sequences which enhance expression of theOm genes. In the present study, we examined whether or not the long terminal repeats (LTR) of thetom element contain such an eye imaginal disc-specific enhancer, usingD. melanogaster transformants containing alacZ gene ligated to thetom LTR. Analyses oflacZ gene expression in the eye imaginal discs of third instar larvae of 18 independently established transformant lines showed that thetom LTR was capable of enhancinglacZ expression in all the transformant lines, but the degree of enhancement varied between lines. In addition, the effect of thetom LTRlacZ gene evidently changed when thetom LTR construct was relocated to different chromosomal positions. On the basis of these findings, it is hypothesized that ectopic and excessive expression of theOm genes in the eye imaginal discs is induced by an eye imaginal disc-specific enhancer present in thetom LTR, the effect of which may be subject to chromosomal position effects.     

Une espéce nouvelle ďophisaurus (lacertilia,anguidae) de ľoligocène des phosphorites du quercy. révision de la sous-famille des anguinae

Ophisaurus roqueprunensis is a new anguine species (Lacertilia, Anguidae) from the Oligocene of the Phosphorites du Quercy (France). Blade-like teeth are the main feature of the new taxon. Several characters demonstrate the monophyletic nature of the Anguinae subfamily. The Anguinae subfamily is now subdivided into three groups: the genusPseudopus, with enlarged (molariform) teeth at the rear of the dental row; the anguine lizards with blade-like teeth (caniniform) or theAnguis —Ophisaurus harti lineage and the AmericanOphisaurus lizards, a group that shares no derived character and, thus, is a metataxon.Ophisaurus roqueprunensis is placed within theAnguis- Ophisaurus harti lineage. Phyletic relationships within those three taxons are envisaged.     

Heathland vegetation of the northern-central part of the Iberian Peninsula

Heathland vegetation of northern Spain, included in theCalluno-Ulicetea, was studied using a set of 802 phytosociological relevés. The existing syntaxonomy has been tested and most of the types (associations and subassociations) fit satisfactorily with the observed groupings. Two main problems were encountered within theUlex dominated communities of the Cantabrian fringe and the Castilian-Cantabrian heathland communities. Both groups of communities were subject to ordination in order to clarify relationships between them. For the former group, ordination suggests that three associations can be distinguished: theUlici-Ericetum vagantis (lowlands up to the submontane belt), theVaccinio-Ulicetum gallii for the communities of higher altitudes (montane belt) and theUlici-Ericetum ciliaris (hygrophilous heathlands). The Castilian-Cantabrian heathlands show a variable Mediterranean influence and have a dispersed distribution due to lithological conditions. This results in the distinction of two new associations, viz. theArctostaphylo crassifoliae-Daboecietum cantabricae (marly, water-retaining soils) and theEricetum scopario-vagantis (sandy soils). A complete classification of theCalluno-Ulicetea in the studied area and short ecological and biogeographical diagnoses are given.     

Study ofH-2 mutations in mice VI. M523, a newK end mutant

A newH-2 mutation was found in a mouse belonging to CBA/CaLacSto (H-2 ^k ) strain and designated 523, the proposed haplotype symbol for which isH-2 ^ka . The line CBA.M523 carries this mutation and is fully congenic with the parental strain, except for the mutant site 523. The mutation 523 is located within theK- end of theH-2 gene complex. Phenotypically, it causes prompt skin graft rejection and pronounced graft-versus-host activity in strain combination CBA/Sto⇄C-BA.M523. Attempts to produce active alloantisera in the same strain combination have so far been unsuccessful.     

Use of nalidixic acid for constructing the replication map of theMycobacterium phlei chromosome

Nalidixic acid was used for describing more accurately the terminal replication region of theMycobacterium phlei chromosome. Cell division in synchronized cultures was not sensitive to this acid any more between 185–190 min,i.e. about 10 min after replication of theser gene the last of 24 genes of the replication map described so far. The replication of the chromosome was controlled by determining the position of thebac gene. Microscopic studies in phase contrast of the cells that were subjected for long time periods to nalidixic acid treatment at a bactericidal concentration showed elongated cells. The electron-microscopic observation showed that a portion of the population influenced by nalidixic acid lyzes, whereas other cells remain intact and resemble control cells.     

Probing a functional role of Glu87 and Trp89 in the lid ofHumicola lanuginosa lipase through transesterification reactions in organic solvent

To reveal the functional role of Glu87 and Trp89 in the lid ofHumicola lanuginosa lipase, site-directed mutagenesis at Glu87 and Trp89 was carried out. The catalytic performance of wild-type and mutated lipases was studied in transesterification reactions in cyclohexane at a controlled water activity. Two different acyl donors were used in the investigation: tributyrin, a natural substrate for a lipase, and vinyl butyrate, an activated ester suitable for fast and efficient lipase-catalyzed transformations in preparative organic synthesis. As acyl acceptor 1-heptanol was used. The Glu87Ala mutation decreased theV _max,app value with tributyrin and vinyl butyrate by a factor of 1.5 and 2, respectively. TheK _m,app for tributyrin was not affected by the Glu87Ala mutation, but theK _m,app for vinyl butyrate increased twofold compared to the wild-type lipase. Changing Trp89 into a Phe residue afforded an enzyme with a 2.7- and 2-fold decreasedV _max,app with the substrates tributyrin and vinyl butyrate, respectively, compared to the wild-type lipase. No significant effects on theK _m,app values for tributyrin or vinyl butyrate were seen as a result of the Trp89Phe mutation. However, the introduction of a Glu residue at position 89 in the lid increased theK _m,app for tributyrin and vinyl butyrate by a factor of >5 and 2, respectively. The Trp89Glu mutated lipase could not be saturated with tributyrin within the experimental conditions (0–680 mM) studied here. With vinyl butyrate as a substrate theV _max,app was only 6% of that obtained with wild-type enzyme.     

Syntaxonomy of theTrifolio-Geranietea (saum vegetation) in Slovenia

This paper summarises present knowledge of the natural saum vegetation (Trifolio-Geranietea: Trifolion medii, Geranienion andDictamno-Ferulagenion) in Slovenia. The alliance ofGeranion sanguinei was subdivided into theGeranienio (primarily of Central European distribution) and SubmediterreanDictamno-Ferulagenion. Several new syntaxa (Scorzonero villosae-Trifolietum alpestris, Cirsio-Clematidetum rectae andOrigano-Cnidietum silaifolii) were described within theDictamno-Ferulagenion.     

The high-rank syntaxa of the rock-cliff and scree vegetation of the mainland Greece and Crete

A revision was undertaken of the high-rank syntaxa of the vegetation occurring in rock fissures, ledges and screes of mainland Greece and Crete. All published phytosociological relevés available were collected and subjected to numerical classification and ordination. Four orders (Androsacetalia vandelii, Onosmetalia frutescentis, Potentilletalia speciosae andPetromaruletalia pinnatae) comprising 8 alliances (one of them new) were distinguished within theAsplenietea trichomanis (rock fissures, clefts, and ledges). The scree vegetation was classified partly within theThlaspietea rotundifolii (Drypidetalia spinosae with 2 alliances) and partly within theDaphno-Festucetea (Saturejo-Scutellarietalia—a new order, with 2 alliances). Ordination revealed clear differences in floristic composition of the alliances distinguished. The studied chasmophytic vegetation of Greece contains a very high proportion of endemics which serve as diagnostic species of the syntaxa. Further, an analysis of chorological species spectra suggested that the chorological homogeneity of a syntaxon should be considered an important diagnostic feature at high-syntaxon levels.