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1.
The systematic position ofCathaya, a relic genus of thePinaceae, was discussed based on therbcL gene sequence. The sequence data were analysed with PAUP and MEGA programs. The great genetic distance value betweenCathaya and any other genus of thePinaceae showed thatCathaya was a distinct and isolated genus. The most parsimonious Fitch tree and neighbor-joining tree showed thatCathaya was distantly related to the clade comprisingAbies, Keteleeria, Pseudolarix andTsuga, and a sister group relationship betweenCathaya andPinus was weakly supported.Pseudotsuga is closely related toLarix. In theAbies-Keteleeria-Pseudolarix-Tsuga clade,Abies has a close relationship toKeteleeria whilePseudolarix is relatively closely related toTsuga. 相似文献
2.
Bayesian and maximum‐likelihood (ML) analyses of the combined multigene data (nuclear SSU rDNA, and plastid SSU and LSU rDNA) were conducted to evaluate the phylogeny of photosynthetic euglenoids. The combined data set consisted of 108 strains of photosynthetic euglenoids including a colorless sister taxon. Bayesian and ML analyses recovered trees of almost identical topology. The results indicated that photosynthetic euglenoids were divided into two major clades, the Euglenaceae clade (Euglena, Euglenaria, Trachelomonas, Strombomonas, Monomorphina, Cryptoglena, Colacium) and the Phacaceae clade (Phacus, Lepocinclis, Discoplastis). The Euglenaceae clade was monophyletic with high support and subdivided into four main clades: the Colacium, the Strombomonas and Trachelomonas, the Cryptoglena and Monomorphina, and the Euglena and Euglenaria clades. The genus Colacium was positioned at the base of the Euglenaceae and was well supported as a monophyletic lineage. The loricate genera (Strombomonas and Trachelomonas) were located at the middle of the Euglenaceae clade and formed a robust monophyletic lineage. The genera Cryptoglena and Monomorphina also formed a well‐supported monophyletic clade. Euglena and the recently erected genus Euglenaria emerged as sister groups. However, Euglena proxima branched off at the base of the Euglenaceae. The Phacaceae clade was also a monophyletic group with high support values and subdivided into three clades, the Discoplastis, Phacus, and Lepocinclis clades. The genus Discoplastis branched first, and then Phacus and Lepocinclis emerged as sister groups. These genera shared a common characteristic, numerous small discoid chloroplasts without pyrenoids. These results clearly separated the Phacaceae clade from the Euglenaceae clade. Therefore, we propose to limit the family Euglenaceae to the members of the Euglena clade and erect a new family, the Phacaceae, to house the genera Phacus, Lepocinclis, and Discoplastis. 相似文献
3.
Gerald J. Gastony 《American journal of botany》1981,68(6):808-819
The most mature spores available in herbarium specimens of the dicksoniaceous genera Cystodium, Thyrsopteris, and Culcita were studied by scanning electron microscopy and light microscopy, and representative specimens were analyzed to determine the number of spores produced per sporangium. Thyrsopteris and Culcita feature 64-spored sporangia, but Cystodium is consistently 32-spored. Spores were analyzed both in their native state as found on the specimens and in a perine-free state achieved by treatment with sodium hydroxide or acetolysis mixture. The sodium hydroxide assay demonstrated the presence of a perine in Cystodium, Thyrsopteris, and Culcita subgenus Culcita, but no evidence of a perine so defined was found in Culcita subgenus Calochlaena. Spores of Cystodium feature a nearly psilate exine overlain by a striate inner perine and a granular outer perine and are in several respects similar to those of Metaxya in the cyatheoid-dicksonioid complex and to those of Saccoloma in the dennstaedtioids. The most mature Thyrsopteris spores available may not have been fully mature. They feature a sparsely distributed, granular perinous layer over a microverrucate sculptine. The latter topography is taken as largely perinous since treatment with sodium hydroxide left a nearly psilate exine. The spore morphologies of Cystodium and Thyrsopteris reinforce the taxonomic distinctness of these monotypic genera indicated by their other characters. The two subgenera of Culcita are very dissimilar in their spore morphologies. The exine in subgenus Culcita ranges from psilate to slightly microverrucate proximally and distally, with varying margo development. Spores of subgenus Calochlaena are strongly differentiated from those of subgenus Culcita by their exine of broad spinules which vary in their degree of lateral fusion to each other and in the granular appearance of their distal surfaces. Spore morphology in Culcita strongly supports the argument of those who would raise its subgenera to generic rank. 相似文献
4.
Susumu Terabayashi 《Journal of plant research》1981,94(2):141-157
The floral vasculature in three allied genera,Plagiorhegma, Jeffersoria andAchyls is investigated, and the results are compared with those ofEpimedium andVancouveria which are related closely toPlagiorhegma andJeffersonia.
The vasculature in the receptacle ofPlagiorhegma andJeffersonia is similar, but that ofAchlys is much simpler. Slightly different trace patterns are observed in the sepals ofPlagiorhegma andJeffersonia. InJeffersonia, the 3-trace condition leaving 2 or 3 gaps is most frequently observed, but inPlagiorhegma traces of a double nature leaving a single gap are more frequent. The traces to the innermost sepals, petals and stamens
are usually of a double nature leaving a single gap in both genera. Regular division and fusion are not observed in the receptacular
stele. The vascular differentiation between sepals and petals is more advanced inPlagiorhegma andJeffersonia than inEpimedium andVancouveria. InAchlys, the traces are all staminal and single throughout their course.
Two parts recognized in the pistils ofPlagiorhegma, Jeffersonia andAchlys are traversed by independent vasculature. The comparisons of pistil morphology including vasculature ofPlagiorhegma, Jeffersonia, Achlys, Epimedium andVancouveria lead to the interpretation that the pistils are based on the same morphological plan. The probable evolutionary trend in
pistil is then suggested in these five genera. 相似文献
5.
Two new thick‐tail scorpions in the genus Parabuthus Pocock, 1890 are described from the gravel plains of the Central Namib Desert, Namibia: Parabuthus glabrimanus sp. nov. ; Parabuthus setiventer sp. nov. The two new species occupy discrete distributional ranges, allopatric with the closely related species Parabuthus gracilis Lamoral, 1979 and Parabuthus nanus Lamoral, 1979. The distributions of the four species are mapped and a key provided for their identification. Revised diagnoses are provided for P. gracilis and P. nanus. The two new species are added to a previously published morphological character matrix for Parabuthus species and their phylogenetic positions determined in a reanalysis of Parabuthus phylogeny. Parabuthus setiventer sp. nov. is found to be the sister species of P. nanus, whereas P. glabrimanus sp. nov. is sister to a monophyletic group comprising P. gracilis, P. nanus, and P. setiventer sp. nov. The discovery of two new scorpion species endemic to the Central Namib gravel plains contributes to a growing body of evidence that this barren and desolate region is a hotspot of arachnid species richness and endemism. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 159 , 673–710. 相似文献
6.
7.
The fouling of mooring facilities in Nakhodka Bay, Sea of Japan, has been studied. The main fouling communities have been distinguished dominated by green algae Enteromorpha linza and Ulva fenestrata, brown algae Laminaria japonica and Costaria costata, a hydroid Obelia longissima, a polychaete Pseudopotamilla occelata, cirripede barnacles Balanus crenatus and Semibalanus cariosus, a bivalve mollusk Mytilus trossulus, and an ascidian Halocynthia aurantium. The naturalization of some species-invaders in the fouling of mooring facilities in Nakhodka Bay has been registered, namely hydroids Laomedea flexuosa and Clytia languida, a polychaete Pseudopotamilla occelata, and a bryozoan Bowerbankia gracilis. 相似文献
8.
The attack rate of a population of the braconid parasitoid Cotesia glomerata, introduced into the USA over 100 years ago as a parasitoid of Pieris rapae, was compared with that of a native British population, which normally attacks P. brassicae, and with that of a P. rapae specialist, Cotesia rubecula. British C. glomerata attacked P. brassicae at a much higher rate than it attacked P. rapae. In comparison with British C. glomerata, C. rubecula showed a higher attack rate with P. rapae. American C. glomerata attacked P. rapae at a slightly higher rate than did British C. glomerata, but not at as high a rate as that achieved by C. rubecula. The differences in each comparison were statistically significant. The possible causes of the differences between British and American C. glomerata attacking P. rapae are discussed. They may be due to genetic or environmental effects. Egg load did not appear to be a factor limiting the number of hosts parasitized under the conditions of the experiments. 相似文献
9.
During a continued survey of fungi accommodated in the Calosphaeriales, we observed that the genus Romellia is morphologically heterogeneous. Historically, four species were placed in the genus. Romellia was introduced for taxa with globose, dark, superficial, papillate perithecia, a paraphysate centrum, and octosporous asci containing eight allantoid, hyaline ascospores. The type species, R. vibratilis, was revised in our study, and its freshly collected material was cultured. The anamorph obtained in vitro matches the generic concept of the hyphomycete genus Phaeoacremonium, the anamorph of Togninia. The phylogenies inferred from newly obtained sequences of LSU rDNA, β-tubulin, and actin of R. vibratilis revealed that the species is congeneric with Togninia (Togniniaceae) and represents a good species. Revision of type and herbarium material of other Romellia species confirmed they are not congeneric with Togninia. Romellia tympanoides possesses immersed, subglobose perithecia with sessile asci containing eight ascospores, which during maturation produce ascoconidia filling the entire ascus. This maturation process represents a new kind of apparent polyspory known in the ascomycetes. We introduce a new genus, Conidiotheca, and a new combination for R. tympanoides. The species is compared with the genera Barrina and Tympanis. The relationships of two other Romellia species, R. ambigua and R. cornina, lie with Wegelina and Jattaea of the Calosphaeriales. 相似文献
10.
《Bioscience, biotechnology, and biochemistry》2013,77(6):1238-1246
The egI gene, encoding a major endoglucanase (EGI) of Scopulariopsis brevicaulis TOF-1212, was cloned and sequenced. The egI gene consisted of 868 bp with one intron and encoded a protein of 229 amino acids with a calculated molecular mass of 22,392 daltons. The EGI was assigned to a family 45 of glycosyl hydrolases and showed high similarity with other fungal endoglucanases, especially with those of Humicola grisea and Fusarium oxysporum, on the basis of hydrophobic cluster analysis. The egI gene was expressed under the promoter of the phosphoglycerate kinase gene (PGK) in Saccharomyces cerevisiae. The transformed cells were able to secrete the enzyme efficiently in an active form. 相似文献
11.
E. E. Schilling 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,94(6-7):925-933
Chloroplast DNA (cpDNA) restriction site data were used to analyze phylogenetic relationships within Helianthus. Data from new samples were consistent with previous results and showed the genus to be a well-defined (11 site changes)
lineage within subtribe Helianthinae. The affinities of 2 species, Viguiera similis and V. phenax (V. ludens) that have sometimes been included in Helianthus were shown to lie outside the genus. The two species of Phoebanthus, however, formed a phylogenetic ingroup to the perennial Helianthus. Within the genus, cpDNA data indicated that there are four distinct phylogenetic lineages. Two of the lineages each contained
a single, annual species (H. agrestis and H. porteri, respectively). The remaining annual species collectively formed a third lineage (sect. Helianthus). The fourth lineage contained all of the perennial species, including those of Phoebanthus. Within the perennial lineage, there was little variation in restriction site characters. The 3 species of series Pumili formed a paraphyletic group at the base of the perennial lineage, and the 3 species of series Ciliares formed a group that was supported by a single restriction site character.
Received: 2 September 1996 / Accepted: 25 October 1996 相似文献
12.
13.
Summary The morphology and fine structure of the vibratile anterior dorsal fin of the rockling Gaidropsarus mediterraneus are described. 60–80 fin rays project as a fringe from a reduced fin web; their lateral movement maintains the fin in almost constant rapid undulation, at a frequency of 3–4 beats per second. The fin can be laid back and with-drawn into a groove. Erector and depressor muscles, which are histologically distinct, move each ray. The fin support is modified, incorporating elastic cartilage, and enclosed in a capsule of collagenous connective tissue. The epidermis at the frontal and caudal aspect of each ray contains numerous receptor cells, over 100,000 per mm2, which have an apical microvillus and synaptic connections with nerve fibres. The recurrent facial nerve sends a major branch to the dorsal fins, which is joined by dorsal ramuli of spinal nerves. It is calculated that there are three to six million receptor cells on the vibratile fin and in the epidermis of the dorsal groove, in individuals of average size. Taste buds do not occur in the skin of the groove, contrary to a previous report, nor on the vibratile fin rays, although they are present on the prominent most anterior fin ray and elsewhere on the fins and barbels. The undulatory motion of the fin draws sea water towards and through the vibratile rays and backwards as a perceptible current. The fin constitutes a specific sensory organ, a water sampler, peculiar to this rockling and related species.Abbrevations used in figures
a
aperture
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am
axial muscles
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bl
base of lepidotrichion
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cc
collagenous capsule
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dlc
dorsal longitudinal canal
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dr
distal radial
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drs
dorsal ramulus of a spinal nerve
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e
epidermal cell(s)
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ec
elastic cartilage
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en
extracapsular branch of the recurrent facial nerve
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fm
fin membrane
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fr
fin ray
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frn
fin ray nerve
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in
intracapsular branches of the recurrent facial nerve
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l
lepidotrichia
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n
nerve plexus
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ns
neural spine
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pr
proximal radial
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rc
receptor cell(s)
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rdm
radial depressor muscle
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rem
radial erector muscle
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s
scales
-
t
tendons
Dedicated to Professor Konrad Lorenz on the occasion of his 80th birthday 相似文献
14.
Summary The Bz2 locus of Zea mays has been cloned, utilizing the presence of the transposable element Dissociation (Ds) at the locus as a gene tag. The Ds element inserted in the bz2-m allele was identified among many members of the Ac/Ds family in a Southern blot analysis of a population segregating for bz2-m and Bz2. After cloning a DNA fragment from the bz2-m allele, sequences flanking the Ds insertion were shown to be Bz2-specific and were used to isolate a homologous fragment from a wild-type Bz2 line. The Ds insertion in the bz2-m allele was found to be a Ds2 element identical to the Ds insertion in adh1-2F11. 相似文献
15.
A Rhizobium tropici DNA region carrying the amino-terminal half of a nodD gene and a nod-box-like sequence confers host-range extension 总被引:1,自引:0,他引:1
Carolina Sousa Jorge Luis Folch Purificación Boloix Manuel Megías Noreide Nava Carmen Quinto 《Molecular microbiology》1993,9(6):1157-1168
Rhizobium tropici CIAT899 is a broad-host-range strain that, in addition to Phaseolus, nodulates other plant legumes such as Leucaena and Macroptilium. The narrow-host-range of Rhizobium leguminosarum biovars phaseoli (strain CE3) and trifolii (strain RS1051) can be extended to Leucaena esculents and Phaseolus vulgaris plants, respectively, by the introduction of a DNA fragment 521 bp long, which carries 128 amino acids of the amino-terminal region of a nodD gene from R. tropici, as well as a putative nod-box-like sequence, divergently oriented. The 521 bp fragment, in the presence of L. esculenta or P. vulgaris root exudates, induced a R. leguminosarum bv. viciae nodA-lacZ fusion in either a CE3 or RS1051 background, respectively. 相似文献
16.
The type series of Progynotaenia evaginata Fuhrmann, 1909 from Burhinus senegalensis in Sudan, P. foetida Meggitt, 1928 from B. oedicnemus in Egypt and Angularia australis Maplestone, 1921 from B. grallarius in Australia are redescribed. As a comparative material, specimens of P. evaginata from B. oedicnemus in Kazakhstan were studied. The type-series of P. evaginata and P. foetida were found to be heterogeneous due to the presence of scoleces and fragments of cestodes of the genus Stenovaria Spasskii & Borgarenko, 1973 (Dilepididae). For P. foetida, a lectotype is designated. P. foetida is recognised as a synonym of P. evaginata (new synonymy). Angularia australis, previously considered a member of the Dilepididae, is transferred to the Progynotaeniidae as a synonym of P. evaginata (new synonymy). The synonymy of P. indica Johri, 1963 with P. evaginata, proposed by Ryzhikov & Tolkacheva (1981), is supported. The host range and the geographical distribution of P. evaginata are restricted to birds of the genus Burhinus from the Eastern Hemisphere. 相似文献
17.
The 3.5 kb nucleotide fragment, including the recA gene and its downstream recX-like gene, has been isolated from a genomic library by dot-blot hybridization with the Mycobacterium smegmatis recA gene. The recA gene, consisting of 1047 base pairs (bp), encodes a polypeptide of 348 amino acids while the recX-like gene, consisting of 450 bp, encodes a shorter polypeptide of 149 amino acids. Both the deduced amino acid sequences of recA and recX resemble those of the recA and recX genes from other bacteria. The cloned Amycolatopsis mediterranei U32 recA gene conferred partial resistance to ethyl methane sulfonate when expressed in E. coli with the lacZ promoter. 相似文献
18.
Frank Stumpf Lidija Halda Walter Klingmüller 《Molecular & general genetics : MGG》1993,241(1-2):236-240
A small plasmid containing the entire nif gene cluster of Enterobacter agglomerans 333 as an excisable cassette has been constructed, using pACYC177 as a vector. Two cosmid clones taken from a gene library of E. agglomerans plasmid pEA3 were used as a source of nif genes. A SmaI fragment of peaMS2-2, containing the H,D,K,Y,E,N,X,U,S,V,W,Z,M,L,A and B genes and an ApaI fragment of peaMS2-16 containing nifA,B,Q,F and J were selected to construct pMH2. The resulting plasmid of 33 kb carries the complete nif gene cluster as a nif cassette on a single XbaI fragment. The nif construct pMH2 in Escherichia coli strains has significant nitrogenase activity compared to wild-type E. agglomerans 333. The nif gene cluster construct was found to be very stable. 相似文献
19.
The morphology of many hypogeous fungi converges on a homogeneous reduced form, suggesting that disparate lineages are subject to a uniform selection pressure. The primary goal of this study was to evaluate the morphology and infer the phylogeny of the Leucogastrales with Mycolevis siccigleba using a Bayesian methodology. A comprehensive morphological assessment was used for an a priori phylogenetic inference to guide the sequencing effort. All structures except spore ornamentation pointed to the Albatrellaceae as the most likely sister taxon. Polyporoletus sublividus, a close relative of Albatrellus, produces ornamented basidiospores with a similar structure to M. siccigleba basidiospores. The ITS from 30 taxa was used for the molecular phylogenetic analysis. P. sublividus was found sister to Mycolevis. Leucophleps spinispora and L. magnata formed a group sister to the Polyporoletus/Mycolevis group, whereas Leucogaster was polyphyletic with respect to the core of the Leucogastrales and sister to A. caeruleoporus. This relationship was expected as previously undescribed chlamydospores produced by members of Albatrellus had a similar morphology to the basidiospores of L. rubescens. 相似文献
20.
Cuadrado Y Fernández M Recio E Aparicio JF Martín JF 《Applied microbiology and biotechnology》2004,64(2):228-236
The first two genes of the threonine pathway, ask and asd, were cloned and sequenced from the aminoethoxyvinylglycine-producing Streptomyces sp. NRRL 5331. The two genes are organized in a bicistronic operon. ask, encoding the apartokinase (ASK), is located upstream from asd. The presence of a ribosome-binding site within the ask sequence suggests that this open reading frame encodes two overlapping proteins. The formation of both subunits of the aspartokinase from a single gene was studied using antibodies raised against the C-terminal end of the aspartokinase subunits. Disruption of asd results in a significant decrease of aminoethoxyvinylglycine production, thus supporting the involvement of the ask–asd operon in the biosynthesis of this metabolite. This is the first report in which a gene cluster for the first two steps of aminoethoxyvinylglycine biosynthesis is characterized.Abbreviations
ASD
Aspartate semialdehyde dehydrogenase
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ASK
Aspartokinase
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AVG
Aminoethoxyvinylglycine 相似文献