Hygrocybe rubida,a new species from Kerala State,India

Hygrocybe rubida, a new species in subsection Squamulosae of section Coccinea, collected from tropical evergreen forests of Western Ghats of Kerala is formally described. The species is characterized by a bright red, dry pileus and stipe; ovoid to subamygdaliform spores; a distinctly sterile lamella-edge with crowded cheilocystidia and a trichodermial pileipellis.     

Transposable DNA elements and life history traits: II. Transposition of P DNA elements in somatic cells reduces fitness, mating activity, and locomotion of Drosophila melanogaster

Some transposable DNA elements in higher organisms are active in somatic cells, as well as in germinal cells. What effect does the movement of DNA elements in somatic cells have on life history traits? It has previously been reported that somatically active P and mariner elements in Drosophila induce genetic damage and significantly reduce lifespan. In this study, we report that the movement of P elements in somatic cells also significantly reduces fitness, mating activity, and locomotion of Drosophila melanogaster. If other elements cause similar changes in life history traits, it is doubtful if transposable DNA elements remain active for long in somatic cells in natural populations.     

Extrachromosomal DNA in Bacillus thuringiensis var. kurstaki, var. finitimus, var. sotto, and in Bacillus popilliae

Four entomopathogenic bacteria contained extrachromosomal deoxyribonucleic acid (DNA) molecules of various sizes. Bacillus thuringiensis var. kurstaki contained twelve elements banding on agarose gels that ranged from 0.74 to > 50 × 10⁶ daltons, three of which were giant extrachromosomal DNA elements. B. thuringiensis var. sotto contained one giant extrachromosomal DNA element with a molecular size of about 23.5 × 10⁶ daltons and two lesser elements of 0.80 and 0.62 × 10⁶ daltons. B. thuringiensis var. finitimus harbored two giant DNA elements corresponding to >50 × 10⁶ daltons and two lesser bands with relative small size (0.98 and 0.97 × 10⁶ daltons). B. popilliae contained no giant extrachromosomal DNA elements but did contain two smaller elements corresponding to 4.45 and 0.58 × 10⁶ daltons. The possible use of extrachromosomal DNA elements that prove to be autonomous replicons for recombinant DNA studies is discussed.     

New species of <Emphasis Type="Italic">Clitocybe </Emphasis>and <Emphasis Type="Italic">Crepidotus </Emphasis>(Agaricales) from eastern Honshu,Japan

 Three new species of Agaricales from eastern Honshu, Japan, are described and illustrated. (1) Clitocybe minutella sp. nov. (section Vernae), having white, very small, clitocyboid basidiomata with white, strigose mycelial tomentum at the base of the stipe and trichodermial elements in the pileipellis, occurs on leaf litter in deciduous oak forests. (2) Crepidotus longicomatus sp.nov. (section Echinospori), forms very small (up to 3.5 mm in diameter), reniform basidiomata densely covered overall with white to pale yellow, erect, thick-walled, long hairs. It has melleous, echinulate basidiospores, and was found on fallen dead branches in lowland oak forests. (3) Crepidotus virgineus sp. nov. (section Crepidotus), forming pure white, reniform basidiomata, has smooth, ellipsoid basidiospores, subfusiform-pedicellate to irregularly cylindrical cheilocystidia, and abundant clamp connections. It occurs on fallen dead branches in lowland oak forests. Received: August 22, 2002 / Accepted: January 8, 2003 Acknowledgments I am grateful to Dr. Yousuke Degawa (KPM) for allowing the specimens cited to be kept in the Kanagawa Prefectural Museum of Natural History. Correspondence to:H. Takahashi     

环柄菇属中国一新记录种——橙褶环柄菇

报道了中国环柄菇属的一个新记录种——橙褶环柄菇[Lepiota citrophylla(Berk.Broome) Sacc.],标本采自中国云南省勐腊县勐仑镇绿石林公园。该种的鉴别特征是菌褶浅橙色,担孢子侧面观近圆柱形,褶缘囊状体棒状或窄棒状,盖表鳞片呈栅状排列,末端细胞无明显分化,近圆柱状或稍窄棒状,具锁状联合。该种被置于卵孢环柄菇组。     

The transposable element impala,a fungal member of the Tc1-mariner superfamily

A new transposable element has been isolated from an unstable niaD mutant of the fungus Fusarium oxysporum. This element, called impala, is 1280 nucleotides long and has inverted repeats of 27 bp. Impala inserts into a TA site and leaves behind a “footprint” when it excises. The inserted element, impala-160, is cis-active, but is probably trans-defective owing to several stop codons and frameshifts. Similarities exist between the inverted repeats of impala and those of transposons belonging to the widely dispersed mariner and Tc1 families. Moreover, translation of the open reading frame revealed three regions showing high similarities with Tc1 from Caenorhabditis elegans and with the mariner element of Drosophila mauritiana. The overall comparison shows that impala occupies an intermediate position between the mariner and Tcl-like elements, suggesting that all these elements belong to the same superfamily. The degree of relatedness observed between these elements, described in different kingdoms, raises the question of their origin and evolution.     

Flipper, a mobile Fot1-like transposable element in Botrytis cinerea

A transposable element, Flipper, was isolated from the phytopathogenic fungus Botrytis cinerea. The element was identified as an insertion sequence within the coding region of the nitrate reductase gene. The Flipper sequence is 1842?bp long with perfect inverted terminal repeats (ITRs) of 48?bp and an open reading frame (ORF) of 533 amino acids, potentially encoding for a transposase; the element is flanked by the dinucleotide TA. The encoded protein is very similar to the putative transposases of three elements from other phytopathogenic fungi, Fot1 from Fusarium oxysporum, and Pot2 and MGR586 from Magnaporthe grisea. The number of Flipper elements in strains of B. cinerea varied from 0 to 20 copies per genome. Analysis of the descendants of one cross showed that the segregation ratio of Flipper elements was 2:2 and that the copies were not linked.     

Genome-wide analysis of long,exact DNA repeats in rhizobia

The rhizobia are a group of bacteria widely studied for their capacity to form intimate symbiotic relationships with leguminous plants. However, they are also interesting for containing a remarkable abundance of repetitive genetic elements, such as long DNA repeats. In this study we deeply analyzed long, exact DNA repeats in five representative rhizobial genomes; Rhizobium etli, Rhizobium leguminosarum, Bradyrhizobium japonicum, Sinorhizobium meliloti and Mesorhizobium loti. The results suggest that a huge proportion of repeats can be located in either plasmid or chromosome replicons, except in B. japonicum, which lacks plasmids, but contains the largest number, and longest repeat elements of the genomes analyzed here. Interestingly, we detected a slight correlation between the density of repeats (either number or length) and genome size. As expected, the highest percentage of DNA repeats code for mobile genetic elements, including insertion sequences, recombinases, and transposases. Some repeats corresponded to non-coding or intergenic regions, while in genomes like that of R. etli, a significant percentage of large repeats, mainly located in plasmids, were strongly associated with symbiotic and nitrogen fixation activities. In conclusion, our analysis shows that rhizobial genomes contain a high density of long DNA repeats, which might facilitate recombination events and genome rearrangements, functioning in adaption and persistence during saprophytic or symbiotic life.     

Characterization of a Tc1-like transposable element in zebrafish (Danio rerio)

We have characterized Tdr1, a family of Tc1-like transposable elements found in the genome of zebrafish (Danio rerio). The copy number and distribution of the sequence in the zebrafish genome have been determined, and by these criteria Tdr1 can be classified as a moderately repetitive, interspersed element. Examination of the sequences and structures of several copies of Tdr1 revealed that a particular deletion derivative, 1250 by long, of the transposon has been amplified to become the dominant form of Tdr1. The deletion in these elements encompasses sequences encoding the N-terminal portion of the putative Tdr1 transposase. Sequences corresponding to the deleted region were also detected, and thus allowed prediction of the nucleotide sequence of a hypothetical full-length element. Well conserved segments of Tc1-like transposons were found in the flanking regions of known fish genes, suggesting that these elements have a long evolutionary history in piscine genomes. Tdr1 elements have long, 208 by inverted repeats, with a short DNA motif repeated four times at the termini of the inverted repeats. Although different from that of the prototype C. elegans transposon Tc1, this inverted repeat structure is shared by transposable elements from salmonid fish species and two Drosophila species. We propose that these transposons form a subgroup within the Tc1-like family. Comparison of Tc1-like transposons supports the hypothesis that the transposase genes and their flanking sequences have been shaped by independent evolutionary constraints. Although Tc1-like sequences are present in the genomes of several strains of zebrafish and in salmonid fishes, these sequences are not conserved in the genus Danio, thus raising the possibility that these elements can be exploited for gene tagging and genome mapping.     

Trace elements (Al,Cd, Cr,Cu, Fe,Mn, Ni,Pb and Zn) in Mytilus galloprovincialis and Tapes decussatus from Faro and Ganzirri Lakes (Sicily,Italy): Flow cytometry applied for hemocytes analysis

BackgroundTrace elements present in sessile molluscs, are important because they are used in human consumption and it has significantly increased in recent years. While their filtering of the water can lead to their build-up of organic and inorganic materials that can be sampled and analyzed, this can also lead to bioaccumulation of harmful substances, such as essential and non-essential elements, that can harm the human health if in taken in high concentrations or for a long period of time.MethodsIn the present study, the trace metal content (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of two sessile crustaceans, 20 Mytilus galloprovincialis (mussel) and 20 Tapes decussatus (clam) in Faro and Ganzirri Lakes (Messina, Sicily, Italy) were analyzed. Haemolymph samples were taken on both molluscs in order to analyze the haemocyte population by flow cytometric analysis. Unpaired t-tests were used to determine significant differences for the essential and non-essential metallic elements concentrations in the lake waters and in the tissues of M. galloprovincialis and T. decussatus and for hemocyte populations R1 (halinocytes) and R2 (granulocytes).ResultsThe results suggested that that in Faro Lake, the tissue Al, Cr and Pb levels in M. galloprovincialis were higher than those for T. decussatus, in contrast to Mn, Fe, Ni, Cu, Zn and Cd, which were higher in T. decussatus. Unpaired t-tests showed that there were significantly higher proportions of halinocytes in M. galloprovincialis versus T. decussatus for both Faro Lake (41.8 % vs. 24.3 %; P < 0.001) and Ganzirri Lake (43.0 % vs. 22.4 %; P < 0.001). In contrast, while there were significantly higher proportions of granulocytes in Faro Lake (21.2 % vs. 9.1 %; P < 0.001), this difference was not seen for the granulocytes of M. galloprovincialis versus T. decussatus in Ganzirri Lake (9.6 % vs. 13.0 %).ConclusionThis study shows that M. galloprovincialis and T. decussatus can indeed bioaccumulate some of these metal, such that activation of the immune responses is specific to certain cell types. Future research must focus on the balance of trace elements in the consumption of these shellfish, and analyzes with more sophisticated tools can be used to diagnose the increased concentration of trace elements and the quantification of trace metals from shellfish to clams.     

A new species of Peltidium Philippi, 1839 (Crustacea,Copepoda, Harpacticoida) from the Pacific coast of Mexico

During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.     

Description of Eucyclops tziscao sp. n., E. angeli sp. n., and a new record of E. festivus Lindberg, 1955 (Cyclopoida,Cyclopidae, Eucyclopinae) in Chiapas,Mexico

Two new species of the freshwater cyclopoid genera Eucyclops are described, Eucyclops tziscao sp. n. and E. angeli sp. n. Both species belong to the serrulatus-group defined by morphological features such as: the presence of distal spinules or hair-like setae (groups N1 and N2) on frontal surface of antennal basis; the fourth leg coxa with a strong inner spine that bears dense setules on inner side, yet proximally naked (large gap) on outer side; and a 12-segmented antennule with smooth hyaline membrane on the three distalmost segments. Eucyclops tziscao sp. n. is morphologically similar to E. bondi and E. conrowae but differs from these species in having a unique combination of characters, including a caudal ramus 4.05±0.25 times as long as wide, lateral seta of Enp3P4 modified as a strong, sclerotized blunt seta, coxal spine of fourth leg with inner spinule-like setules distally, and sixth leg of males bearing a strong and long inner spine 2.3 times longer than median seta. Eucyclops angeli sp. n. can be distinguished by an unique combination of morphological features: the short caudal ramus; the long spine on the sixth antennular segment of A1; the presence of one additional group of spinules (N12’) on the caudal surface of A2; the presence of long setae in females, or short spinules in males on the lateral margin of fourth prosomite; the strong ornamentation of the intercoxal sclerite of P4, specially group I modified as long denticles; the distal modified setae of Exp3P3 and Exp3P4 in females and males; and the short lateral seta of P5. Finally, we report on a new record of E. festivus in México, and add data on morphology of the species.     

Chromosome localization and characterization of a family of long interspersed repetitive DNA elements from the genus Zea

This paper describes the characterization and chromosomal distribution of new long repetitive sequences present in all species of the genus Zea. These sequences constitute a family of moderately repetitive elements ranging approximately from 1350 to 1700 copies per haploid genome in modern maize (Zea mays ssp. mays) and teosinte (Zea diploperennis), respectively. The elements are long, probably larger than 9 kb, and they show a highly conserved internal organization among Zea subspecies and species. The elements are present in all maize chromosomes in an interspersed pattern of distribution, are absent from centromeric and pericentric heterochromatin, and with some clustering in the distal regions of chromosome arms.     

Gondolelloid multielement conodont apparatus (Scythogondolella) from the Lower Triassic of Jiangsu,East China,revealed by high-resolution X-ray microtomography

The application of high-resolution X-ray microtomography on conodont natural assemblages has provided new information on the structure of the elements and enabled the three-dimensional reconstruction of apparatuses. We herein report four conodont natural assemblages from uppermost Lower Qinglong Formation, Longtan, Nanjing, East China. Using X-ray microtomography, we reconstructed the apparatus of the end-Smithian (Olenekian, Early Trassic) Scythogondolella milleri. Our result confirms that Scythogondolella has an octomembrate apparatus composed of 15 elements (a single S₀ element, two pairs of S_1–4, M and P_1–2 elements) like other gondolelloid apparatuses that have been tested by their corresponding natural assemblages, including Neogondolella, Novispathodus and Nicoraella. Element morphology of Scythogondolella closely resembles that of Neogondolella apparatus from the Illyrian (Anisian, Middle Triassic) of Monte San Giorgio: an alate (hibbardellan) S₀ element with two long lateral processes that meet at a denticle anterior of the cusp, a bipennate (hindeodellan) S₃ element with a bifurcated anterior process branching from the third denticle anterior of the cusp and an enantiognathiform S₂ element with two dissimilar processes of nearly equal in length. It differs from the latter in the length of the inner-lateral process of M element and the posterior process of S₀ and S_3–4 elements without considering the obvious morphological differences in P elements between them. The element positional homologues of Scythogondolella conforms to those of the standard 15-element plan shared primitively among ozarkodinin, prioniodinin and prioniodontid conodonts, and again confirms that the breviform digyrate elements of cypridodellan and enantiognathiform morphotypes occupy the S₁ and S₂ positions, respectively, within the superfamily Gondolelloidea.     

Parablastocatena tetracerae gen. et sp. nov. and Corynesporella licualae sp. nov. from Hainan, China

Parablastocatena tetracerae gen. et sp. nov. and Corynesporella licualae sp. nov., collected on dead branches of Tetracera asiatica and Licuala fordiana, respectively, in tropical forests of China, are described and illustrated. Parablastocatena tetracerae is the type species for a new monotypic genus in possessing macronematous conidiophores forming distinct synnemata with holoblastic conidiogenesis and euseptate, short-chained conidia ending in a paler brown rostrum, whereas C. licualae is distinguished from described species by the smaller conidia with long appendages. A key to currently accepted species of Corynesporella is provided.