Biogeography of Hysterangiales (Phallomycetidae, Basidiomycota)

To understand the biogeography of truffle-like fungi, DNA sequences were analysed from representative taxa of Hysterangiales. Multigene phylogenies and the results of ancestral area reconstructions are consistent with the hypothesis of an Australian, or eastern Gondwanan, origin of Hysterangiales with subsequent range expansions to the Northern Hemisphere. However, neither Northern Hemisphere nor Southern Hemisphere taxa formed a monophyletic group, which is in conflict with a strictly vicariant scenario. Therefore, the occurrence and importance of long-distance dispersal could not be rejected. Although a pre-Gondwanan origin of Hysterangiales remains as a possibility, this hypothesis requires that Hysterangiales exist prior to the origin of the currently recognized ectomycorrhizal plants, as well as the arrival of mycophagous animals in Australia. This also requires that a basal paraphyletic assemblage represents parallel evolution of the ectomycorrhizal symbiosis, or that Hysterangiales was mycorrhizal with members of the extinct flora of Gondwana. Regardless, models for both ancient and more recent origins of Hysterangiales are consistent with truffle-like fungi being capable of transoceanic dispersal.     

Detection of Ehrlichia and Anaplasma DNA in Ixodes (Exopalpiger) trianguliceps Bir. ticks in Tyumen Province

This paper presents data of study (PCR with fluorescent hybridization probes) of Ixodes (Exopalpiger) trianguliceps Bir. collected from small mammals in the southern taiga forests of Tyumen Province. DNA of Ehrlichia and Anaplasma was detected in ticks of this species for the first time. Cases of mixed infection were also observed.     

A review of the systematics of the sleeper shark genus Somniosus with redescriptions of Somniosus ( Somniosus) antarcticus and Somniosus ( Rhinoscymnus) longus (Squaliformes: Somniosidae)

Past treatments of the sleeper shark genus Somniosus generally recognize three species: S. microcephalus, S. pacificus, and S. rostratus. Based on morphometrics and meristics, we conclude that this genus includes two subgenera (Somniosus and Rhinoscymnus) and five species. Subgenus Somniosus differs from Rhinoscymnus by being much larger when adult and in having more numerous tooth rows in the lower jaw, hooklike rather than leaf-shaped dermal denticles, more numerous spiral valve and vertebral counts, and a poorly calcified vertebral column. Subgenus Somniosus includes S. (Somniosus) microcephalus and S. (S.) pacificus of the Northern Hemisphere and S. (S.) antarcticus of the Southern Hemisphere. Although Somniosus antarcticus has been synonymized with S. microcephalus and identified as S. pacificus in past literature, it differs from S. microcephalus in having a shorter interdorsal space, a more posterior first dorsal fin, lower dorsal fins, more numerous tooth rows in the lower jaw, more numerous spiral valve counts, and fewer precaudal vertebrae. Somniosus antarcticus also differs from S. pacificus by having a shorter prebranchial length, lower dorsal fins, more numerous spiral valve counts, and slightly more precaudal vertebrae. Subgenus Rhinoscymnus includes S. (Rhinoscymnus) rostratus from the eastern North Atlantic and Mediterranean Sea (senior synonym of S. bauchotae) and S. (R.) longus from the western Pacific Ocean. Somniosus longus has been synonymized with S. rostratus, but differs in having a relatively longer second dorsal fin, a slightly larger eye, more lower tooth rows, and slightly higher spiral valve counts. Both Somniosus (Somniosus) antarcticus and S. (Rhinoscymnus) longus from the Pacific Ocean were redescribed. A key to the species and the geographical distribution of all species are provided.     

Origin of the subgeneraCyclampterium, Paralampterium andSciadiopeplus fromLophocyrtis (Lophocyrtis) (Radiolaria, Theoperidae)

Work on the exceptionally well-preserved, rapidly accumulating Bath Cliff Section, Barbados and supplementary Deep Sea Drilling Project samples, has revealed the evolutionary origins of three stratigraphically useful species in theCryptoprora ornata Zone straddling the Eocene/Oligocene boundary and demonstrated the origin of the genusCyclampterium. Elucidation of the origin ofCyclampterium milowi necessitates a revision of the generaLophocyrtis andCyclampterium.Lophocyrtis (Lophocyrtis)jacchia is the ancestor ofL. (Cyclampterium)hadra, the earliest member in the subgenusCyclampterium which comprises the anagenetic lineage leading fromL. (C.)hadra toL. (C.)neatum. The monotypic subgenusSciadiopeplus branches off from an early member in theCyclampterium lineage. The new speciesL. (L.)exitelus andL. (S.)oberhaensliae terminate the subgeneraLophocyrtis andSciadiopeplus, respectively. During the investigation it also became clear that morphotypes resembling earlyL. (C.)milowi could be found in mid and high latitude assemblages in the late Early and late Middle Eocene. The origin of one these morphotypes was also traced toL. (Lophocyrtis)jacchia giving rise to the new subgenusParalampterium. This lineage includes the new speciesL. (Paralampterium)dumitricai and two species questionably assigned to it,L. (Paralampterium)?longiventer and the new speciesL. (Paralampterium) ?galenum. The relationship ofL. (P.)dumitricai toL. (P.) ?longiventer andL. (P.) ?galenum is unknown.     

Chromosomal Mapping ofTmp(Emp1),Xmp(Emp2), andYmp(Emp3), Genes Encoding Membrane Proteins Related toPmp22

We have recently characterized a novel mammalian gene family, encoding membrane glycoproteins with four trans-membrane domains. This gene family includes the previously studiedPMP22,which is involved in the Charcot–Marie–Tooth neuropathy, and three novel genes:TMP, XMP,andYMP(HGMW-approved symbolsEMP1, EMP2andEMP3,respectively). TheTmp(tumor-associated membrane protein) gene was isolated from a c-mycinduced mouse brain tumor and is expressed in several highly proliferative cell types. We have now isolated cDNAs of the mouseXmpandYmpgenes and determined the chromosomal localization of mouseTmp, Xmp,andYmp. Tmpwas mapped to mouse chromosome 6,Xmpwas mapped to chromosome 16, andYmpwas mapped to chromosome 7.TmpandYmpmap to paralogous chromosomal regions, whereasXmpmaps to a chromosomal region that is putatively paralogous to a region on chromosome 11, to whichPmp22was previously mapped. These data suggest that this family of membrane glycoproteins evolved as a result of chromosomal duplications.     

dnaA suppressor (dasF) mutants of Escherichia coli are stable DNA replication (sdrA/rnh) mutants

Summary The possible allelic relationship between dasF (dnaA suppressor) and sdrA/rnh (stable DNA replication/RNase H) mutations was examined. dasF mutations could not only suppress various dnaA(ts) mutations, but also the insertional inactivation of the dnaA gene or deletion of the oriC sequence, as could sdrA mutations. dasF mutants were found to exhibit the stable DNA replication phenotype, and the sensitivity to rich media, of sdrA mutants. The dasF and sdrA mutations were mapped very closely between metD and proA on the E. coli genetic map. The mutations were recessive to the wild-type allele for all the above phenotypes. It was concluded that dasF is allelic to sdrA/mh.     

Revision of some Thecaphora species (Ustilaginomycotina) on Caryophyllaceae

Specimens of Thecaphora saponariae s. lat. from several caryophyllacean host plants belonging to the genera Cerastium, Dianthus, Petrorhagia, Saponaria, Silene, and Stellaria were studied by means of both LM, SEM, and molecular phylogenetic analyses using ITS and LSU rDNA sequences. The data show that T. saponariae s. lat. is not uniform but represents several taxa. Molecular phylogenetic analyses, correlated with morphology of the sori, spore balls, and spores, permitted the recognition of five species. Two new species, Thecaphora italica and T. cerastii are described, and two new combinations, T. alsinearum and T. melandrii are proposed. The anamorph of Thecaphora saponariae is reported for the first time. A lectotype is designated for Sorosporium silenes-inflatae. Evolutionary aspects are discussed.     

The effect of seasonality on oxidative metabolism in Nacella (Patinigera) magellanica

We studied the seasonal variation on aerobic metabolism and the response of oxidative stress parameters in the digestive glands of the subpolar limpet Nacella (P.) magellanica. Sampling was carried out from July (winter) 2002 to July 2003 in Beagle Channel, Tierra del Fuego, Argentina. Whole animal respiration rates increased in early spring as the animals spawned and remained elevated throughout summer and fall (winter: 0.09 ± 0.02 μmol O₂ h^− 1 g^− 1; summer: 0.31 ± 0.06 μmol O₂ h^− 1 g^− 1). Oxidative stress was assessed at the hydrophilic level as the ascorbyl radical content / ascorbate content ratio (A / AH⁻). The A / AH⁻ ratio showed minimum values in winter (3.7 ± 0.2 10^− 5 AU) and increased in summer (18 ± 5 10^− 5 AU). A similar pattern was observed for lipid radical content (122 ± 29 pmol mg^− 1 fresh mass [FW] in winter and 314 ± 45 pmol mg^− 1 FW in summer), iron content (0.99 ± 0.07 and 2.7 ± 0.6 nmol mg^− 1 FW in winter and summer, respectively) and catalase activity (2.9 ± 0.2 and 7 ± 1 U mg^− 1 FW in winter and summer, respectively). Since nitrogen derived radicals are thought to be critically involved in oxidative metabolism in cells, nitric oxide content was measured and a significant difference in the content of the Fe–MGD–NO adduct in digestive glands from winter and summer animals was observed. Together, the data indicate that both oxygen and nitrogen radical generation rates in N. (P.) magellanica are strongly dependent on season.     

Mating systems in representatives of Parmeliaceae, Ramalinaceae and Physciaceae (Lecanoromycetes, lichen-forming ascomycetes)

The progeny of meiosis of eight Parmeliaceae, two Ramalinaceae and seven Physciaceae were subjected to fingerprint analysis using RAPD-PCR applied to single spore isolates. The sample set included common and widespread rarely fertile species (Parmelia sulcata, Pseudevernia furfuracea, Physcia tenella), local to common, infrequently fertile species (Melanelixia glabra, Parmelina tiliacea, Xanthoparmelia conspersa, X. stenophylla, Anaptychia runcinata, Diploicia canescen, Physconia distorta), local to rare, infrequently or regularly fertile species with declining distributions (Parmelina carporrhizans, P. quercina, Ramalina fastigiata, R. fraxinea, Anaptychia ciliaris), and local to common, regularly fertile species (Physcia aipolia, P. stellaris). All species turned out to be heterothallic, polymorphisms among RAPD markers ranging from 10–87 %. The significance of these findings for population genetics and conservation biology, and potential reasons for infrequent ascoma formation in some of the species are discussed.     

Die Schneefinken (GattungenMontifringilla undLeucosticte)

Ohne Zusammenfassung     

Copia and Gypsy retrotransposons activity in sunflower (Helianthus annuus L.)

Background  

Retrotransposons are heterogeneous sequences, widespread in eukaryotic genomes, which refer to the so-called mobile DNA. They resemble retroviruses, both in their structure and for their ability to transpose within the host genome, of which they make up a considerable portion. Copia- and Gypsy-like retrotransposons are the two main classes of retroelements shown to be ubiquitous in plant genomes. Ideally, the retrotransposons life cycle results in the synthesis of a messenger RNA and then self-encoded proteins to process retrotransposon mRNA in double stranded extra-chromosomal cDNA copies which may integrate in new chromosomal locations.     

Quinua and Relatives (Chenopodium sect.Chenopodium subsect.Celluloid)

Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.     

Spore control (Sco) mutations in Bacillus subtilis

Summary Spore control (Sco) mutants were isolated after nitrosoguanidine-induced mutagenesis of germinated spores. They were recognized as colonies showing high proteolytic activity on protein-agar (generally elastin-agar) test plates. Fourteen such mutants were isolated. The Sco mutations were transferred by transformation into an isogenic collection of genetically marked strains. Most of them appeared to be single mutations. Transduction experiments permitted the localisation of six Sco mutants in three loci, all in the argC-metC region. ScoA is located between argC and metC, ScoB is to the right of metC and ScoC is to the left of argC. ScoC and the previously described catA mutation are probably placed in the same gene.Two ScoC strains also appear to carry a second mutation, ScoD, probably localised in the same locus as ScoB or in a locus close to it. Eight other Sco mutations, apparently unlinked to the argC-metC region, were not localised. The results indicate complex regulation of sporulation-associated products such as the proteases, dependent on several genes.     

Spore control (Sco) mutations in Bacillus subtilis

Summary Morphogenesis of spore control (Sco) mutants of Bacillus subtilis was followed by quantitative electron microscopy. In wild type cultures the morphological stages II, III, IV and V attain their peaks of frequency at 1.5, 3.5, 4.5 and 5 h after t ₀, respectively. Stages II and IV are short, stages III and V occupy the main part of the process. Morphogenesis is slowed down in Sco A1, Sco B2 and Sco12 strains: all the stages are delayed and prolonged. Stage III cells are predominant for a long time, until t ₉ or later. It is suggested that the mechanism which switches off sporulation genes is affected and this leads to overproduction of sporulation-associated products. In other Sco mutants, such as Sco C3, part of the population sporulates normally but a fraction of cells persists for a long time at stages III and V. The pleiotropy of the spore control mutations is discussed.     

Natural occurrence of entomopathogenic fungi ( Zygomycetes : Entomophthorales ) of aphid ( Hemiptera : Aphididae ) pests of horticultural crops in Argentina

A three-year survey of entomophthoralean pathogenic fungi of aphids from horticultural crops in La Plata, Argentina, was conducted. Nine species of aphids, including Aphis fabae Scopoli, Aphis gossypii Glover, Brevicoryne brassicae (L.), Lipaphis erysimi (Kaltenbach), Macrosiphum euphorbiae (Thomas), Myzus sp., Myzus persicae (Sulzer), Nasonovia ribisnigri (Mosley) and Capitophorus elaeagni (del Guercio) were recorded as hosts of entomopathogenic fungi. Six species of Entomophthorales that infected and killed aphids were found in vegetable crops. The fungal species identified were Conidiobolus obscurus (Hall & Dunn) Remaudière & Keller, Entomophthora planchoniana Cornu, Neozygites fresenii (Nowakowski) Remaudière & Keller, Pandora neoaphidis (Remaudière & Hennebert) Humber, Zoophthora radicans (Brefeld) Batko and Zoophthora sp. Pandora neoaphidis was the most predominant pathogen of aphids and was found throughout the summer (December–March) 2004. The recovery of C. obscurus, N. fresenii and P. neoaphidis represent first records of these fungi for South America.     

The phylogenetic placement of Ostropales within Lecanoromycetes (Ascomycota) revisited

Results of molecular studies regarding the phylogenetic placement of the order Ostropales and related taxa within Lecanoromycetes were thus far inconclusive. Some analyses placed the order as sister to the rest of Lecanoromycetes, while others inferred a position nested within Lecanoromycetes. We assembled a data set of 101 species including sequences from nuLSU rDNA, mtSSU rDNA, and the nuclear protein-coding RPB1 for each species to examine the cause of incongruencies in previously published phylogenies. MP, minimum evolution, and Bayesian analyses were performed using the combined three-region data set and the single-gene data sets. The position of Ostropales nested in Lecanoromycetes is confirmed in all single-gene and concatenated analyses, and a placement as sister to the rest of Lecanoromycetes is significantly rejected using two independent methods of alternative topology testing. Acarosporales and related taxa (Acarosporaceae group) are basal in Lecanoromycetes. However, if the these basal taxa are excluded from the analyses, Ostropales appear to be sister to the rest of Lecanoromycetes, suggesting different ingroup rooting as the cause for deviating topologies in previously published phylogenies.     

Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless

The Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy.