Molecular diversity and relationships of North American Elymus trachycaulus and the Eurasian E. caninus species

The morphological similarity of Elymus trachycaulus to the Eurasian E. caninus has often been noted. This has lead to controversial and contradicting taxonomic treatments. Nevertheless, there has been no systematic investigation on molecular genetic similarity between E. trachycaulus and E. caninus. In this study, random amplified polymorphic DNA (RAPD) analysis was used to study the similarity between the two species. RAPD analysis of 38 samples representing E. caninus and E. trachycaulus complex yielded 111 interpretable RAPD bands. The Jaccard’s similarity values for E. caninus ranged from 0.38 between accessions H10345 and H10353 to 0.97 between accessions H8745 and H10096, with an average of 0.67. The Jaccard’s similarity values for E. trachycaulus complex ranged from 0.09 between E. trachycaulus ssp. subsecundus (PI 537321) and E. trachycaulus ssp. violaceus (PI 272612) to 0.78 between accessions PI 315368 and PI 372644, with an average of 0.43. The results from different analyses (NJ and PCA) were similar but not identical. The molecular genetic separation between E. caninus and E. trachycaulus was consistent. The PCA analysis clearly separated all E. caninus accessions from E. trachycaulus and its subspecies. The NJ analysis also showed separation between most accessions of E. caninus and E. trachycaulus. Further analysis excluding E. trachycaulus ssp. subsecundus and ssp. violaceus revealed that E. caninus species and E. trachycaulus species were clearly separated into two distinct groups. The RAPD data thus support the treatment of E. caninus and E. trachycaulus as distinct species. The analyses further indicate that E. violaceus is nested within E. trachycaulus, and more related to E. trachycaulus complex rather than to E. caninus.     

Re-evaluation of the taxonomic status of sand boas of the genus Eryx (Daudin, 1803) (Serpentes: Boidae) in north-eastern Iran using sequences of the mitochondrial genome

The sand boas of the genus Eryx (Daudin, 1803) comprise four species in northe-astern Iran: E. tataricus (Lichtenstein, 1823), E. miliaris (Pallas, 1773), E. elegans (Gray, 1849), and E. jaculus (Linnaeus, 1758). Based on a morphological study of the Eryx species in the area, a high similarity between E. tataricus and E. miliaris on the one side, and E. jaculus and E. elegans on the other side has been well documented, so that they are hardly distinguishable from each other. We analysed sequences of the mitochondrial cytochrome b gene of 29 individuals of morphotypes of this species complex in north-eastern Iran to clarify the phylogenetic relationships. Based on the branch pattern of the phylogenetic trees, the amounts of genetic distances within and between major clades and considering the morphological data, we concluded that the traditional grouping of species within the genus Eryx in north-eastern Iran should be fundamentally revised. We believe that E. elegans is conspecific with E. jaculus, and E. tataricus is conspecific with E. miliaris. Considering the principle of priority, the north-eastern populations of Eryx in Iran should be classified into only two distinct species: E. jaculus and E. miliaris.     

Genomic in situ hybridization identifies genome donor of finger millet (Eleusine coracana)

Eleusine coracana, commonly called finger millet, is an important cereal of semi-arid regions, cultivated in parts of Africa and India for its grain. It is reported to be an allotetraploid with a chromosome number 2n = 4x = 36, and diploid species E. indica, with chromosome number 2n = 2x = 18, is considered to be one of its genome donors. In situ hybridization of the E. coracana genome with the genomic DNA of various diploid species of the genus confirmed that E. indica is one of the genome donors to E. coracana and that E. floccifolia is another genome contributor to this allotetraploid species. In situ hybridization also showed a close genomic relationship between 4 diploid species, E. indica, E. floccifolia, E. tristachya and E. intermedia, and also between these and tetraploid species E. coracana. The common genomic in situ hybridization (GISH) signals of the genomic DNA of E. indica and E. tristachya on 15–18 chromosomes of E. coracana clearly indicated that these 2 species have a close genomic similarity. GISH on 25–27 chromosomes of E. coracana withthe genomic DNA of E. intermedia and cross in situ hybridization signals on the chromosomes of E. coracana with genomic DNA of E. intermedia and E. indica or E. intermedia and E. floccifolia has showed that E. intermedia may be an intermediate species of E. indica and E. floccifolia. Received: 15 May 2000 / Accepted: 4 September 2000     

Towards an explanation of the altitudinal distributions of three species of Eucalyptus in central Tasmania

Eucalyptus gunnii, E. rodwayi and E. ovata are parapatrically distributed in grassy woodlands at high, medium and low altitude, respectively, in central Tasmania. Seedlings from provenances from the middle of the altitudinal ranges of all species were capable of survival for 18 months on sites dominated by the other two species. However, 9 years after planting E. ovata had died out in open vegetation on all sites. In contrast, E. rodwayi had survived in open vegetation on all sites and was the sole or major survivor in the two lower altitude areas. E. gunnii had performed marginally better than E. rodwayi in the open vegetation at the highest altitude site, had survived in the E. rodwayi site and had died out in the E. ovata site. The results of field trials, and experiments in the glasshouse and laboratory, suggested that E. ovata is absent from open vegetation at the higher altitudes because of its susceptibility to frost, that E. rodwayi dominates the middle altitudes because of its superior frost resistance, that E. gunnii dominates the highest altitudes because of superior growth rates to E. rodwayi in misty and cool conditions, and that E. ovata is dominant at low altitudes because of its superior growth rates in warm conditions. Recent climatic changes are posited to have had some effect on the results of the field experiment.     

Taxonomic, nomenclatural and chorological notes on several taxa of the genus Echinodorus (Alismataceae)

Taxonomic, nomenclatural and chorological notes on several taxa of the genus Echinodorus are given. A new species E. maculatus is described. The name Alisma intermedium (basionym of the name E. intermedius) is lectotypified. Echinodorus major and E. martii should be treated as two distinct taxa. The name E. xinguensis was invalidly published. It is also confirmed that E. africanus, E. veronikae and E. viridis (all belonging to the E. uruguayensis group) do not originate from Africa. The name E. bleherae should be written with a female suffix (-ae); this name is considered here as a synonym of the earlier name E. grisebachii.     

Molecular phylogeny evidence of altitudinal distribution and habitat adaptation in Korean Ephemera species (Ephemeroptera: Ephemeridae)

Molecular phylogeny of the four Korean Ephemera species, Ephemera orientalis, E. sachalinensis, E. strigata, and E. separigata, was inferred from 630 bp sequences of the partial mitochondrial cytochrome c oxidase I (COI) gene. Results indicated that mean intraspecific sequence divergences were 0.70%, whereas mean interspecific divergences were 15.75%, and 17 samples were distinguished to four species correctly by COI sequences. The results also demonstrated that four species of Korean Ephemera assembled a monophyletic group with high support in maximum parsimony and maximum likelihood analyses. This Ephemera group was divided into two major clades of E. orientalis–E. sachalinensis and E. strigata–E. separigata. Furthermore, we demonstrated that this phylogeny explained altitudinal and habitat adaptations of Korean Ephemera species. The E. orientalis–E. sachalinensis clade, a widespread and lowland‐adapted mayfly group, retained plesiomorphic traits such as paired stripes on abdominal segments and was regarded as plesiotypic in terms of habitat adaptation, compared to the geographically more limited and upland‐adapted E. strigata–E. separigata clade.     

Phylogeography of the East Asian polymitarcyid mayfly genus Ephoron (Ephemeroptera: Polymitarcyidae): a comparative analysis of molecular and ecological characteristics

In East Asia, the mayfly genus Ephoron, a member of Polymitarcyidae, has been classified into three species: Ephoron eophilum, Ephoron limnobium, and Ephoron shigae. Using the nuclear histone 3 and internal transcribed spacer 1 and mitochondrial 16S rRNA and cytochrome c oxidase subunit I genes, we investigated the phylogenetic relationships of these mayflies. Ephoron limnobium formed polyphyletic relationships within the clade of Japanese E. shigae and shared identical sequences with E. shigae, suggesting that E. limnobium is a synonym of E. shigae. Monophyly was supported in E. eophilum, Korean E. shigae, and E. limnobium + Japanese E. shigae. Ephoron eophilum that co‐occurs with the other Ephoron species has several peculiar traits in its adult swarming period and karyotype. This suggests that both pre‐ and post‐zygotic isolation are likely to have promoted speciation of these Ephoron species. The divergence between E. eophilum and E. shigae would have occurred from the late Late Miocene to Early Pliocene according to the Bayesian relaxed clock model calibrated using the mitochondrial substitution rate. The area currently inhabited by E. eophilum emerged above sea level some 0.1 Mya, suggesting that E. eophilum moved into this area from other areas that it occupied prior to this time. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 181–202.     

Sensitivity of Aedes aegypti adults (Diptera: Culicidae) to the vapors of Eucalyptus essential oils

Vapors of essential oils extracted from various species of Eucalyptus (E. gunnii, E. tereticornis, E. grandis, E. camaldulensis, E. dunnii, E. cinerea, E. saligna, E. sideroxylon, E. globulus ssp. globulus, E. globulus ssp. maidenii, E. viminalis and the hybrids E. grandis × E. tereticornis and E. grandis × E. camaldulensis) and their major components were found to be toxic to Aedes aegypti adults, the yellow fever mosquito.An aliquot of each oil was placed in a cylindrical test chamber and the number of knocked-down mosquitoes was recorded as function of time. Knockdown time 50% was then calculated. Results showed that E. viminalis had the fastest knockdown time at of 4.2 min, on the same order as dichlorvos, a standard knockdown agent. A correlation was observed between the content of 1,8-cineole in the Eucalyptus essential oils and the corresponding toxic effect.The correlation between KT₅₀ values and calculated vapor pressures of the essential oil components showed that the fumigant activity of simple organic compounds in insects is correlated with their volatility.     

THE GENOME CONSTITUTION AND PHYLOGENY OF ELYMUS AMBIGUUS

Two Elymus ambiguus Vasey & Scribn. collections from Utah and Idaho were 2n = 28, and the species behaved meiotically as an allotetraploid. The E. ambiguus plants were highly self-sterile, and they hybridized readily with Asian E. junceus Fisch. (2n = 14), E. karataviensis Roshev. (2n = 28), E. multicaulis Kar. & Kir. (2n = 28), and North American E. innovatus Beal (2n = 28). Chromosome pairing at metaphase-I in the E. ambiguus X E. junceus triploid hybrids indicated that one E. ambiguus genome was closely homologous with the E. junceus genome. Chromosome pairing in the tetraploid hybrids indicated that both E. ambiguus genomes were more or less homologous with the genomes of E. karataviensis, E. multicaulis, and E. innovatus. The basic genome formula of E. ambiguus may be written as JJXX, where J is the E. junceus genome and X is a genome of unknown origin. Chromosome pairing in the hybrids indicated that E. ambiguus is more closely related to North American E. innovatus than to the Asian species. The E. ambiguus X E. innovatus hybrids were the only hybrids that set seed. Gene flow between E. ambiguus and E. innovatus is biologically possible, but geographic separation of the species precludes natural introgression.     

Molecular phylogenetic relationship of Epinephelus based on sequences of mtDNA Cty b

The mtDNA Cyt b gene was sequenced partially for Variola louti of Serranidae, Epinephelinae and seven endemic species of groupers—Epinephelus awoara, E. brunneus, E. coioides, E. longispinis, E. sexfasciatus, E. spilotoceps and E. tauvina in China. The seven endemic species and other seven foreign species of groupers—E. aeneus, E. caninus, E. drummondhayi, E. haifensis, E. labriformis, E. marginatus and E. multinotatus from the GenBank were combined and analysed as ingroup, while Variola louti was used as outgroup. We compared the 420 bp sequences of Cyt b among the 15 species and constructed two types of molecular phylogenetic trees with maximum parsimony method (MP) and neighbor-joining method (NJ) respectively. The results were as follows: (1) As to the base composition of mtDNA Cyt b sequence (402 bp) of 14 species of Epinephelus, the content of (A + T) was 53.6%, higher than that of (G + C) (46.4%). The transition/transversion ratio was 4.78 with no mutation saturation. (2) The cluster relationships between E. awoara and E. sexfasciatus, E. coioides and E. tauvina, E. longispinis and E. spilotoceps were consistent with phenotypes in taxonomy. (3) In the phylogenetic tree, the species in the Atlantic Ocean were associated closely with those in the Pacific Ocean, which suggested that the Cyt b sequences of Epinephelus were highly conserved. This may be attributed to the coordinate evolution. (4) In wel1-bred mating or heredity management, mating Epinephelus of the same branch should be avoided. It is likely to be an effective way to mate the species of the Atlantic Ocean with those of the Pacific Ocean to improve the inheritance species. __________ Translated from Acta Hydrobiologica Sinica, 2006, 30(4): 432–438 [译自: 水生生物学报]     

Production of Monoclonal Antibody Discriminating Serological Difference in Escherichia coli O9 and O9a Polysaccharides

A monoclonal antibody (mAb) with a unique antigenic specificity against Escherichia coli O9 was produced. The O9a mAb was reactive with a part of the strains in E. coli O9. The O9a mAb did not react with LPS from the E. coli O9 test strain Bi316-42. The distribution of the antigen defined by the O9a mAb in E. coli O9 was consistent with that of E. coli O9a present in E. coli O9 strains. The chemical structure of the repeating unit of the O-specific polysaccharide detected by the mAb was demonstrated to be a mannotetraose by two-dimensional nuclear magnetic resonance spectroscopy. It was confirmed that the mAb recognized E. coli O9a serotype in E. coli O9 serotype strains, suggesting that E. coli O9a serotype might be a dominant strain in E. coli O9.     

Antibacterial and Antifungal Spectra of Antibiotics Produced by Different Strains of Erwinia herbicola (= Pantoea agglomerans)

Nine antibiotic producer strains of Erwinia herbicola (=Pantoea agglomerans), belonging to different groups, strongly inhibited growth of 21 streptomycin sensitive strains and 6 streptomycin resistant strains of E. amylovora. The antibacterial spectra of antibiotics produced by the tested strains of E. herbicola were mainly limited to E. amylovora and related tested species. The tested strains of E. amylovora that are resistant to streptomycin did not show cross-resistance to the different types of antibiotics produced by the tested strains of E. herbicola. The antibiotics produced by the different tested strains of E. herbicola did not exert any activity on tested fungi with the exception that strains Eh 153 and Eh 351 slightly inhibited the growth of Verticillium dahliae.     

Environmental influences on the distribution of the rare Eucalyptus paliformis and the common E. fraxinoides

Abstract Eucalyptus paliformis is restricted to seven small populations within an area of <5 km2 on the Wadbilliga Plateau of south-eastern NSW. It occurs as a dominant tree in habitats superficially similar to those of the more widespread E. fraxinoides, which dominates forests immediately adjacent to the E. paliformis populations. This study examined factors which may influence the replacement of E. fraxinoides by E. paliformis, and similarly, factors which exclude E. paliformis from sites dominated by E. fraxinoides. Seedling growth and competition experiments indicated that E. fraxinoides outcompetes E. paliformis under unburnt field conditions, on field soils, under high and low moisture regimes, under high light and high nutrient conditions, and under a range of temperature regimes. Thus, it is likely that E. paliformis is excluded from E. fraxinoides sites by competition. However, further investigation of the competitive relationship between the two species under recently-burnt conditions is still required to test this hypothesis. The exclusion of E. fraxinoides from E. paliformis sites is unlikely to be due to soil types or moisture regimes. Further, temperature regimes do not appear to be important in reducing the competitive advantage of E. fraxinoides over E. paliformis, leaving survival at low temperature extremes as the most promising avenue for further investigation. Temperature measurements, and evidence for low temperature dormancy mechanisms in seeds of E. paliformis but not E. fraxinoides, support the hypothesis that E. fraxinoides is excluded from E. paliformis sites by low temperature extremes.     

Demonstration of Acid Phosphatase in Eimeria spp.: Partial Characterization of the Enzyme in E. vermiformis1,2

Sporozoite extracts of E. vermiformis, E. stiedai, and E. tenella are rich in acid phosphatase activity. They contain specific enzyme activities equal to or greater than those reported for other highly virulent protozoan parasites. The absolute amount of enzyme activity per oocyst dramatically increases during sporulation of E. stiedai and E. vermiformis. Partial characterization of the acid phosphatase activity of E. vermiformis indicates that sporozoites account for greater than 92% of the total activity in sporubted oocysts, that the enzyme is resistant to inhibition by tartrate, and that it can be separated into two forms by anion exchange chroma-tography.     

The speciation history of northern‐ and southern‐sourced Eranthis (Ranunculaceae) species on the Korean peninsula and surrounding areas

The temporal and spatial origins and evolution of the genus Eranthis have not been previously studied. We investigated the speciation and establishment histories of four Eranthis species: Eranthis byunsanensis, E. pungdoensis, E. stellata, and E. pinnatifida. The sampling localities were Korea, Japan, Jilin in China, and the area near Vladivostok in Primorskiy, Russia. We used 12 chloroplast microsatellite loci (n = 935 individuals) and two chloroplast noncoding regions (rpl16 intron, petL‐psbE intergenic spacer; n = 33 individuals). The genetic diversity, genetic structure, phylogenetic relationships of the four species were analyzed, and their ancestral areas were reconstructed. The high genetic diversity of the Jeju island population of E. byunsanensis and Russian populations of E. stellata indicated these species’ northward and southward dispersal, respectively. The genetic structure analyses suggest that the populations in these four species have limited geographical structure, except for the Chinese E. stellata population (SCP). The phylogenetic analyses suggest that E. byunsanensis and E. pinnatifida are sister species and that Chinese SCP may not belong to E. stellata. The ancestral area reconstruction revealed that the most recent common ancestor of the four species existed in the current Chinese habitat of E. stellata. This study shows that E. byunsanensis and E. pinnatifida originated from a southern Eranthis species and speciated into their current forms near Jeju island and near western regions of Japan, respectively, during the Miocene. E. stellata may have dispersed southward on and near the Korean peninsula, though its specific origin remains unclear. Interestingly, the Chinese E. stellata population SCP suggests that the Chinese population might be most ancient among all the four Eranthis species. E. pungdoensis may have allopatrically speciated from E. byunsanensis during the Holocene. The Korean peninsula and the surrounding areas can be considered interesting regions which provide the opportunity to observe both northern‐ and southern‐sourced Eranthis species.     

Germination requirements and responses to leaf litter of four species of eucalypt

We studied how the responses of four species of eucalypt to leaf litter related to their germination responses to light and water availability. Two of the species (Eucalyptus obliqua and E. baxteri) have a mesic distribution, while the other two (E. oleosa, and E. incrassata) are more xerophytic. We studied the effect of litter on emergence of the four species in a glasshouse experiment. Litter did not affect the emergence of E. incrassata and E. oleosa, but enhanced the emergence of E. obliqua and E. baxteri. Litter increased the seedling mortality of all four species. Germination responses to light and water availability were studied in growth cabinets under controlled conditions. The germination of E. obliqua and E. baxteri was substantially lower under fluorescent light than in darkness, but that of E. oleosa and E. incrassata was not affected by the light environment. The germination of E. obliqua and E. baxteri was significantly reduced by reduced water potential (a). Substantial germination of E. oleosa and E. incrassata occurred even at very low a (less than –1.05 MPa). We conclude that both the shade and the humid micro-environment provided by litter may have contributed to the emergence responses of the four species to litter, and these responses may correspond to ecological adaptations to the different environments in which they live.     

Effects of <Emphasis Type="Italic">Escherichia coli</Emphasis> RraA Orthologs of <Emphasis Type="Italic">Vibrio vulnificus</Emphasis> on the Ribonucleolytic Activity of RNase E In Vivo

RraA is a recently discovered protein inhibitor of RNase E that catalyzes the initial step in the decay and processing of numerous RNAs in Escherichia coli. In the genome of Vibrio vulnificus, two open reading frames that potentially encode proteins homologous to E. coli, RraA-designated RraAV1 and RraAV2, have respectively 80.1% and 59.0% amino acid identity to RraA. The authors report that coexpression of RraAV1 protein in E. coli cells overproducing RNase E rescued these cells from growth arrest and restored their normal growth, whereas coexpression of RraAV2 protein further inhibited the growth of E. coli cells, whose growth was already impaired by overproduction of RNase E. Analyses of the steady-state level of various RNase E substrates indicated that the coexpression of RraAV1 more efficiently inhibited RNase E action than coexpression of RraA, and consequently resulted in the more increased abundance of each RNA species tested in vivo. The inhibitory effect by RraAV2 coexpression on RNase E was observed only in the case of trpA mRNA, indicating the possibility of RNA substrate-dependent inhibition of RraAV2 on RNase E. The findings suggest that these regulators of ribonuclease activity have both a conserved inhibitory function and a differential inhibitory activity on RNase E-like enzymes across the species.     

Ethology and ecology of cichlid fishes of the genus Etroplus in Sri Lanka: preliminary findings

Synopsis The Asian cichlid fishes, Etroplus maculatus (Bloch) and E. suratensis (Bloch) were observed in their natural habitat. Ecological and behavioral interactions of these species have not been previously reported. E. suratensis benefits from being cleaned by E. maculatus; it is doubtful the ingestion of parasites and fungi is of much direct benefit to E. maculatus. The advantage to E. maculatus is more likely the survival and reproductive success of adult E. suratensis which in turn provide eggs and eleutheroembryos for the egg-young predatory habit of E. maculatus. Predation is lessened by age-specific crypticity of E. suratensis. E. maculatus displays a unique behavior during its parental cycle where both parents actively defend their young until they are nearly sexually mature and almost the size of the parents. Adult E. suratensis engage in altruistic multiple parental care where several adults care for a single brood that presumably were spawned by only two of the adults. Such behavior has not been reported previously for fish.     

Molecular cloning,characterization, and sequencing of the hemolysin gene from Edwardsiella tarda

Hemolysis is a major symptom of diseased eels infected by Edwardsiella tarda. The hemolysin gene of E. tarda strain ET16 was cloned into plasmid pSK and expressed in Escherichia coli. The mol. mass of the functional β-hemolysin was estimated to be approximately 34 kDa by gel filtration and by SDS-PAGE followed by in situ hemolysin activity analysis. The cloned fragment containing the β-hemolysin locus from E. tarda strain ET16 expressed in E. coli was estimated to be 5.3 kb in length; the deduced gene product was identical in mol. mass and properties to the extracellular products of E. tarda strain ET16. The presence of EcoRI and XbaI sites within the β-hemolysin gene of E. tarda was determined from the loss of hemolytic activity in subclones. Analysis of the DNA sequence of a 2,436-bp HaeIII-HindIII fragment that included EcoRI and XbaI sites revealed three ORFs organized as an operon that encoded three predicted polypeptides of 15,874, 7,055, and 34,804 Da. A 34-kDa polypeptide expressing hemolytic activity in cell lysates of the clone DH5α(pETH3E) is very likely the β-hemolysin encoded by the third ORF. The observation that hemolytic activity appeared in the culture medium of E. tarda, but not in that of E. coli strain DH5α(pETH3E) indicates the existence of a mechanism for transporting the hemolysin across the cell envelope in E. tarda that is different from that of E. coli. Received: 7 July 1995 / Accepted: 24 October 1995     

A redescription of adult females of Ergasilus briani Markewitsch, 1933 (Copepoda: Poecilostomatoida)

The adult female of Ergasilus briani Markewitsch, 1933 (Crustacea: Copepoda) is redescribed using scanning electron and light microscopy. The taxonomic history of E. briani is reviewed. It is confirmed that E. briani and E. minor Halisch, 1934 are synonymous. The known distribution of E. briani in Britain is noted.