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1.
Strains XZ-46A, XZ-105, XZ-129 and XZ-281T isolated from the oral cavities of healthy Tibetan volunteers were revealed to represent two novel ascomycetous yeast species by molecular taxonomic characterizations. Strain XZ-281T was most closely related to Candida humilis , but differed from the type strain of the species by eight (1.2%) substitutions in the 26S rRNA gene D1/D2 domain and by >100 (>20%) mismatches in the internal transcribed spacer (ITS) region. Strains XZ-46A, XZ-105 and XZ-129 had identical or similar D1/D2 and ITS sequences with each other and with strain 17YFT isolated from a leaf of an oak tree ( Quercus sp.). The closest relative of this group was Torulaspora microellipsoides . They differed from the type strain of the species by five (0.9%) substitutions in the D1/D2 domain and >70 (>15%) mismatches in the ITS region. A sexual state was observed in strain 17YFT, but not in the other four oral strains. An anamorphic name Candida pseudohumilis sp. nov. is proposed for strain XZ-281T (=AS 2.3956T=CBS 11404T) and a teleomorphic name Torulaspora quercuum sp. nov. is proposed for strain 17YFT (=AS 2.3768T=CBS 11403T) and the other three oral strains.  相似文献   

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The definition of relatively stable expressed internal reference genes is essential in both traditional blotting quantification and as a modern data quantitative strategy. Appropriate internal reference genes can accurately standardize the expression abundance of target genes to avoid serious experimental errors. In this study, the expression profiles of ten candidate genes, ACT1, ACT2, GAPDH, eIF1, eIF2, α-TUB, β-TUB, TBP, RNA Pol II and RP II, were calculated for a suitable reference gene selection in Paeonia ostii T. Hong et J. X. Zhang leaves under various drought stress conditions. Data were processed by the four regularly used evaluation software. A comprehensive analysis revealed that RNA Pol II was the most stable gene and eIF2 was the least stable one. In addition, the geNorm program provided the optimal choice of two reference gene combination, RNA Pol II and β-TUB, for qRT-PCR normalization in P. ostii subjected to different drought stress levels. Our research provided convenience for gene expression analysis in P. ostii under drought stress and promoted research of effective methods to alleviate P. ostii drought stress in the future.  相似文献   

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A “long‐backed” scenario of hominin vertebral evolution posits that early hominins possessed six lumbar vertebrae coupled with a high frequency of four sacral vertebrae (7:12‐13:6:4), a configuration acquired from a hominin‐panin last common ancestor (PLCA) having a vertebral formula of 7:13:6‐7:4. One founding line of evidence for this hypothesis is the recent assertion that the “Lucy” sacrum (A.L. 288‐1an, Australopithecus afarensis) consists of four sacral vertebrae and a partially‐fused first coccygeal vertebra (Co1), rather than five sacral vertebrae as in modern humans. This study reassesses the number of sacral vertebrae in Lucy by reexamining the distal end of A.L.288‐1an in the context of a comparative sample of modern human sacra and Co1 vertebrae, and the sacrum of A. sediba (MH2). Results demonstrate that, similar to S5 in modern humans and A. sediba, the last vertebra in A.L. 288‐1an exhibits inferiorly‐projecting (right side) cornua and a kidney‐shaped inferior body articular surface. This morphology is inconsistent with that of fused or isolated Co1 vertebrae in humans, which either lack cornua or possess only superiorly‐projecting cornua, and have more circularly‐shaped inferior body articular surfaces. The level at which the hiatus' apex is located is also more compatible with typical five‐element modern human sacra and A. sediba than if only four sacral vertebrae are present. Our observations suggest that A.L. 288‐1 possessed five sacral vertebrae as in modern humans; thus, sacral number in “Lucy” does not indicate a directional change in vertebral count that can provide information on the PLCA ancestral condition. Am J Phys Anthropol 156:295–303, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   

6.
Nine strains of three novel anamorphic yeast species were obtained from samples collected in Thailand including six strains (RV96, RV152, R14, RS9, RS58 and EA1) obtained from estuarine waters collected from two mangrove forests, one strain (ST84) from insect frass and two strains (SR16 and UB13) from forest soils. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene, the nine strains were found to represent three novel Candida species in the Saturnispora clade. Five strains (RV96, RV152, R14, RS9 and RS58) were assigned as a single novel species, which was named Candida sanitii sp. nov. The type strain is RV152T (BCC 25967T=NBRC 103864T=CBS 10864T). Strain EA1 was named as Candida suwanaritii sp. nov. The type strain is EA1T (BCC 29900T=NBRC 104877T=CBS 11021T). Three strains (ST84, SR16 and UB13) represented another novel species, for which Candida sekii sp. nov. is proposed. The type strain is ST84T (BCC 8320T=NBRC 105671T=CBS 10931T).  相似文献   

7.
RÉSUMÉ. Une nouvelle microsporidie, Ormieresia carcini gen. n., sp. n., est trouvée dans Carcinus mediterraneus Czerniavsky, 1884. Son évolution et ses ultrastructures sont étudiees.
Le cycle débute par un méronte limité par une membrane unitaire et possédant un diplocaryon. Toute la sporogonie se déroule dans la musculature de l'höte. Les stades sporogoniaux sont enveloppés dans une membrane pansporoblastique persistante. Dans chaque pansporoblaste, la sporoblastogenése (donnant naissance à 8 sporoblastes) est particulière; un plasmode sporogonial octonucléé manque. Au cours des divisions schizogoniques et sporogoniques, chaque centre cinétique est formé de 2 plaques, une incluse dans l'enveloppe nucléaire, l'autre occupant une position extranucléaire. Les sporontes en division et les sporoblastes sécrètent des substances métaboliques (granules, tubes) qui sont déposées dans l'espace pansporoblastique.
La spore uninucléée est longue et cylindrique (19,1 × 2,4 μm). Un manubrium rectiligne traverse la spore. Son extrémité postérieure se rétrécit brusquement en un filament polaire décrlvant 4 ou 5 tours de spire. L'extrémité antérieure du manubrium est attachée au capuchon polaire lui-même comprimé par un double anneau. La partie antérieure du manubrium est entourée par un polaroplaste formé d'une zone spongieuse et d'une zone lamellaire.  相似文献   

8.
2′,3′-Dihydroxydihydrosuberosin its acetonide derivative and 7-hydroxycoumarin has been isolated from the extracts of Eremocitrus glauca. The s  相似文献   

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Five species of Pleuroxus-like chydorids are found in new material from South Africa or are known from the literature. One species is here described as Dumontiellus africanus gen. n., sp. n., endemic to South Africa. Handling editor: K. Martens  相似文献   

10.
Fourteen native strains of Trichoderma spp. from wildand agricultural pathosystems in the state of Yucatan, Mexico, with growth-promoting ability of Capsicum chinense Jacq. seedlings were evaluated and antagonistic effect of their filtrate against second-stage juveniles (J2) of Meloidogyne incognita. The strains Th05-02 and Th27-08 showed the best significant effects on plant hight variable increments 55.57 and 47.62%, theTh07-04 with 29.48% more root length, theTh02-01 and Th07-04 isolates increased from 48.71 to 84.61% in volume radical and 53.40% of total dry biomass. Statistical analysis (p≤0.001) of Th43 and Th43-13-14 filtrates caused 100% mortality at 24 and 48h. In the test of reversibility to 24 h after replacing the filtrates Th43-13, Th43-14, TH09-06 and TH20-07 by sterile distilled water, the J2 did not recover their viability, so they were considered as the best potential strains of Trichoderma spp. with antagonistic capacity in J2 of M.incognita.  相似文献   

11.
Scanning electron microscopy (SEM) and histological techniques were used to observe and study the setae structures of two gecko species (G. gecko and G. swinhonis) and the relationships between these structures and the adhesive forces. The SEM results showed that the setae of these two species were densely distributed in an orderly fashion, and branched with curved tips. The setae of G. gecko had cluster structures, each cluster containing 4–6 setae whose terminal branches curved towards the center of the toes at ∼ 10°, the tips of the branches like spatulae and densely arrayed at an interval of less than 0.2–0.3 μm. On the contrary, the branch tips in the setae of G. swinhonis were curled, and the terminal parts of setae curved towards the center of the toes at various angles. Usually the setae of these gecko species branch twice at the top at intervals greater than that of G. gecko. The histological observation found that inside the setae of these two species there were plenty of unevenly distributed contents, such as epithelia, fat cells, pigmental cells and muscle tissue, but no gland cells existed. The results of functional experiments suggested that modifying the structure of gecko’s setae could reduce its adhesive ability dramatically, demonstrating the positive correlation between the structure of the gecko’s setae and its adhesive ability. The above results provide important information in designing bio-mimic setae and bio-gecko robots.  相似文献   

12.
This article outlines the life and career of H.A. (Bert) Hawkes, who has been referred to as one of the founders of field ecology, due to the work he conducted in the late 1940s and 1950s, investigating the fly nuisance emanating from biological filters. Following an overview of his life, there is a focus on his core research, carried out over a period of some 50 years, on two aspects of river pollution control—the prevention of pollution by sewage biological filtration and the monitoring of river pollution by biological surveillance.  相似文献   

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A series of naturally occurring 8.O.4′-neolignans (1a–d, 1g, 2g, 2h) and their analogues (1e–f, 1h, 1i, 2a–f, 2i) have been synthesized in racemic form starting from commercially available phenols, such as eugenol, isoeugenol and 4-allyl-2,6-dimethoxyphenol and from aromatic aldehydes, such as piperonal, veratraldehyde and 3,4,5-trimethoxybenzaldehyde. The inhibitory activity of these compounds on superoxide anion (O2.-) release by human polymorphonuclear leukocytes (PMNLs) was tested and the structure-activity relationship was also studied.  相似文献   

15.
Abandonment of traditional agricultural practices in fruit orchards on hillsides in Central Germany results in successive changes in vegetation. We examined three hypotheses relating to these changes: (1) thickets of fleshy-fruited plants develop around planted trees as a result of ornithochory and local soil and site amelioration, (2) woody plants have long-term effects on soil fertility, and (3) thicket development reduces the plant-species diversity of semi-dry grassland between the trees. Field observations and nursery experiments supported the first and second hypotheses. Increased soil fertility, a seed rain of fleshy-fruited shrubs, and shrub establishment occurred mainly around planted fruit trees. Soils from old tree-planting sites remained fertile after the trees had died and disappeared. The third hypothesis was rejected because no decrease in species' richness or diversity occurred during the initial stages of thicket formation. Nevertheless, herbaceous plant species characteristic of the Festuco-Brometea community were absent from the vegetation and seed bank of shaded, nutrient-enriched sites. Conservation of semi-dry grasslands following orchard abandonment will therefore require active control of woody plants.  相似文献   

16.
The morphological characteristics of the seeds of Vicia dasycarpa Ten. cv. Tolse FCA were studied in relation to the area of imbibition water entry and were considered the presence of areoles. Seeds were analyzed using a stereo, optical and scanning electron microscope (SEM). The determination of the initial water entry area was carried out by immersing the seeds in a solution of tetrazolium (1%). This study showed that this species has seeds with a halo framing the hilum, an inconspicuous dry aril and a deltoid micropyle. The seedcoat pattern is papillose. The tracheid bar is surrounded by a ring of parenchymatous cells, and the tracheids show slight warty and non-vestured pits. It was confirmed the presence of an endospermic radicle pocket that surrounds and protect the radical tip. Two pairs of cotyledonar areoles were identified. It was established that the entry of water during imbibition starts in the area of the lens -having cracks- and moves in the sagittal plane. Both citological characteristic of tracheid bar and areoles presence show an apomorfous state between the Papiplionoids.  相似文献   

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Intraspecific diversification of the wildcat (Felis silvestris), including the European wildcat (F. s. silvestris), the Asian wildcat (F. s. ornata) and the African wildcat (F. s. lybica), was examined based on 39 cranial morphology variables. The samples of free‐ranging cats originated from Britain, Europe, Central Asia and southern Africa, consisting of both nominal wildcat specimens (referred to henceforth as ‘wildcats’) and nominal non‐wildcat specimens (‘non‐wildcats’) based on museum labels. The skull morphology of ‘wildcats’ from Britain and Europe is clearly different from that of ‘wildcats’ of Central Asia and southern Africa. The latter are characterized especially by their proportionately larger cheek teeth. On the basis of principal component, discriminant function and canonical variate analyses, the skull morphology of British ‘non‐wildcats’ is less distinct than is that of British ‘wildcats’ from the skull morphologies of ‘wildcats’ of Central Asia and southern Africa. On the other hand, the skull morphology of southern African ‘non‐wildcats’ is as distinct from those of ‘wildcats’ of Britain and Europe as is that of southern African ‘wildcats’. We suggest that the evolution of the modern wildcat probably consisted of at least three different distribution expansions punctuated by two differentiation events: the exodus from Europe during the late Pleistocene, coinciding with the emergence of the steppe wildcat lineage (phenotype of Asian–African wildcat), followed by its rapid range expansion in the Old World. The second differentiation event was the emergence of the domestic cat followed by its subsequent colonization of the entire world with human assistance. Considering the recent evolutionary history of, and morphological divergence in, the wildcat, preventing hybridization between the European wildcat and the domestic cat is a high conservation priority. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83 , 47–63.  相似文献   

19.
Two closely related species of the diatom genus Navicula were investigated using light and electron microscopy. A hitherto unrecorded structure associated with the raphe of N. delognei Van Heurck is described.
Examination of type material revealed that the nomenclatural types of N. grevillii (CA.Ag.) Heiberg and N. comoides (Dillwyn) H. & M. Peragallo do not agree with the present understanding of these species, therefore alternative names were sought. All the synonyms of each species were traced and a table of synonymy is supplied. The names N. delognei and N. pseudocomoides are proposed as replacements for N. grevillii and N. comoides respectively and types are cited.  相似文献   

20.
Macroposthonia sicula n.sp. collected from rhizosphere and roots of olive (Olea europaea L.) at Kamarina, Sicily, Italy, is described and illustrated. It is distinguished from the related species (M. sphaerocephala and M. maskaka) by the longer styler and the characteristic narrowing postvulval portion of the body.  相似文献   

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