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2.
Described are two new species of swallowerfishes—Chiasmodon lavenbergi sp. n. from the western Pacific, differing from other species of the genus by the retaining of epidermal spinules on the skin in adult fishes and by a fixed marginal teeth in the jaws, and Kali caribbaea sp. n. from the southern part of the Caribbean Sea (western Atlantic), differing from other species of the genus by features of dentition and a set of certain other characters.  相似文献   

3.
Abstract:Two new species belonging to the lichen families Pilocarpaceae andEctolechiaceae are described from tropical Africa: Calopadia lucida sp. nov. (Ectolechiaceae) from Tanzania, being similar to C. puiggarii but differing in the UV fluorescent thallus and the pruinose apothecia, andFellhanera ivoriensis sp. nov. (Pilocarpaceae) from the Ivory Coast, differing from the related F. rhapidophylli by the sorediate thallus and from other sorediate taxa by the combination of pale soralia, dark brown apothecia, and the ellipsoid-bacillar conidia. A key to the nine sorediate species of Fellhanera is provided.  相似文献   

4.
《Experimental mycology》1995,19(1):48-60
Rizwana, R., and Powell, W. A. 1995. Ultraviolet light-induced heterokaryon formation and parasexuality in Cryphonectria parasitica. Experimental Mycology 19, 48-60. The effect of ultraviolet-light on heterokaryon formation, vegetative compatibility, and parasexuality in Cryphonectria parasitica was examined. Heterokaryons of complementary auxotrophic strains could not be made by hyphal anastomosis if the strains belonged to different vegetative compatibility groups. Protoplast fusions overcame incompatibility of strains differing in the alleles of a single but not multiple vegetative incompatibility loci. Fusion of protoplasts from ultraviolet light-treated complementary auxotrophs increased heterokaryon formation by 104 to 105 using the strains differing in alleles of a single vegetative incompatibility gene but had no detectable effect on strains differing in multiple vegetative incompatibility genes. Vegetative compatibility tests of single conidial isolates resolved from these heterokaryons suggest that diploids had formed followed by the loss of one of the VIC alleles. Presence of both auxotrophic markers in some of these single conidial isolates confirms the occurrence of a parasexual cycle. These experiments demonstrate that ultraviolet-light can enhance heterokaryon formation and parasexuality in C. parasitica .  相似文献   

5.
We have investigated alloantigen differences which stimulate lymphokine release and3H-TdR uptake in primary ‘one-way’ MLC among allogeneic mice. When mice differing at the wholeH-2 region were tested, MIF and immune IF release was observed, along with a marked3H-TdR uptake. Differences atK, D, orI-S-G regions stimulate both lymphokine release and3H-TdR uptake, though stronger immune IF and3H-TdR responses were observed with differences atI-S-G regions. On the other hand, when mice differing in their minor histocompatibility antigens, and notably at theMls locus, were tested, lymphokine release took place even in the absence of proliferation. Lastly, in MLC between mice differing at multiple minor loci, butH-2 andMls matched, MIF release only, and not immune IF and3H-TdR responses were observed in a few combinations. These findings show that T lymphocytes can recognize alloantigens by releasing lymphokines even without going through proliferation. Moreover, different levels of T-lymphocyte activation exist, depending on the kind of stimulating alloantigens present.  相似文献   

6.
The pileus cuticle is one-layered in a few species ofRussula, but in the others it can be interpreted as composed of two layers—the epicutis uppermost and below this, the subcutis. The basic difference between the two layers is in hyphal orientation. Cell inflation may obscure the orientation in the cuticles of some species. This has given rise to differing interpretations of cuticular structure, especially in regard to the number of nameable layers present, and thus to differing terms for the layers. No Russulas illustrate this better than those of subsectionVirescentinae, of which the two most common North American species,R. crustosa Peck andR. virescens (Schaeffer ex Secretan) Fries, are discussed and described.  相似文献   

7.
Specimens sampled in Central Mongolia have been examined for the intraspecific polymorphism of the nucleotide sequences of ribosomal DNA internal transcribed spacers (ITS1 + 5.8S + ITS2) of the parasitic nematode Haemonchus contortus. A considerable diversity of haplotypes differing in the nucleotide composition of this DNA region has been observed. The phylogenetic relationships between the haplotypes detected in Central Mongolia and the corresponding sequences from other parts of the nematode distribution area (deposited with the NCBI GenBank) have been analyzed. Significantly different sequences have been found along with the haplotypes already observed in H. contortus or differing from them by one-two nucleotides.  相似文献   

8.
The Rieske 2Fe2S cluster of Chlorobium limicola forma thiosulfatophilum strain tassajara was studied by electron paramagnetic resonance spectroscopy. Two distinct orientations of its g tensor were observed in oriented samples corresponding to differing conformations of the protein. Only one of the two conformations persisted after treatment with 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone. A redox midpoint potential (Em) of +160 mV in the pH range of 6 to 7.7 and a decreasing Em (−60 to −80 mV/pH unit) above pH 7.7 were found. The implications of the existence of differing conformational states of the Rieske protein, as well as of the shape of its Em-versus-pH curve, in green sulfur bacteria are discussed.  相似文献   

9.
Osmond CB 《Plant physiology》1972,49(2):260-263
This paper reports effects of salts on in vitro activity of phosphoenolpyruvate carboxylase and ribulose-1,5-diphosphate carboxylase, isolated from species differing in salt tolerance.  相似文献   

10.
Four new mite species (Bakerdania palustris, B. taymyrica, B. mycophila, and B. littoralis) from different regions of Russia are described. Bakerdania palustris sp. n. is most similar to B. janetscheki Mahunka, 1970, differing in the presence of adjoining bases of setae ps 2 and ps 3 (in B. janetscheki, ps 3 is separated from ps 2) and also by shorter smooth setae 2b (in B. janetscheki, setae 2b are serrate and distinctly longer). Bakerdania taymyrica sp. n. is most similar to B. heisseli Mahunka, 1970, differing in the presence of the brush-like setae 1a (that are trichoid and serrate in B. heisseli); shorter setae tc′ on the tibiotarsus I, that are almost half as long as setae pl′ (in B. heisseli, tc′ is much longer, nearly as long as pl′). Bakerdania mycophila sp. n. is most similar to B. racki (Mahunka, 1967), differing in the presence of significantly longer ventral setae and the separate solenidion ω1 (in B. racki, the latter is fused with the tibiotarsus). Bakerdania littoralis sp. n. is most similar to B. racki, differing from the latter in the shape of setae 1a, 2a, 3a, 3b, 4a that are basally thickened; in the shape of setae ps 1 (trichoid in B. racki); and in the presence of the non-furcated setae 1b (in B. racki, these setae are bifurcate).  相似文献   

11.
Distinguishing features of Cyphoderus Collembola of the bidenticulati group are described. Taxonomic problems in the bidenticulati group of Cyphoderus are emphasized, and new characters of taxonomic value are introduced and discussed. Two new species are described from caves of Thailand, differing mainly in claw morphology.  相似文献   

12.
From three Mikania species, three new labdanic acid and two kaurenic acid derivatives have been isolated together with known compounds and four new germacranolides, differing only in the ester moiety.  相似文献   

13.
Lupinus elaphoglossum Barneby, related toL. crotalarioides Mart. ex Benth., but differing in leaves and stipules, is described and illustrated.  相似文献   

14.
The deterrent activity of eight native sesquiterpene lactones isolated from the species Laserpitium siler L., L. archangelica Wulf. and Laser trilobum (L.) Borkh. and one synthetically prepared lactone have been tested against selected storage pest insects. All nine lactones under investigation showed deterrent activity differing according to their structure.  相似文献   

15.
Subject index     
Heats of fusion and heat capacities have been measured for saturated, unsaturated and hydroxy fatty acids, differing in degree of unsaturation, geometric isomerism, and position of unsaturated and hydroxy groups. Entropies of fusion are used to draw conclusions concerning molecular structure of fatty acid chains and lateral chain-chain interactions. Position of the functional group on the chain does not seem to significantly affect the entropy values for trans and cis single double bonds and single triple bonds, but differences are noted with hydroxy group position. Whereas single acid triglycerides of saturated acids have entropies which are about three times that of the corresponding acid, cis and trans single acid triglycerides do not show the same relationship with their corresponding acids. Comparing entropies of fusion for certain groups of fatty acids, only differing in carbon number, allows the estimation of chain equivalence with saturated fatty acids. Hence, for example it is shown that a 22 to 23-carbon cis mono-unsaturated fatty acid is equivalent to an 18-carbon saturated fatty acid.  相似文献   

16.
Antibiotic resistance of Escherichia coli from sows and pigs was determined to compare patterns between pigs of various ages and degrees of antibiotic use. Resistance patterns differed between farm types and pigs of differing ages, indicating that pig age and degree of antibiotic use affect resistance of fecal E. coli.  相似文献   

17.
Fluorescence recovery after photobleaching has been widely used to study dynamic processes in the cell, but less frequently to analyze binding interactions and extract binding constants. Here we use it to analyze γ-tubulin binding to the mitotic spindle and centrosomes to determine the role of γ-tubulin in microtubule nucleation in the spindle. We find rapid γ-tubulin turnover in mitotic spindles of Drosophila early embryos, characterized by diffusional interactions and weak binding, differing from centrosomes with tight binding interactions. The diffusion coefficient of γ-tubulin is consistent with a major species existing in the cytoplasm as the less efficiently nucleating γ-tubulin small complex (γTuSC) or γ-tubulin, rather than γ-tubulin ring complex (γTuRC). The fluorescence recovery kinetics we observe implies that γ-tubulin functions by binding weakly to spindle microtubules. γ-Tubulin may interact transiently with the spindle, nucleating microtubules very rapidly, differing from centrosomes, where γ-tubulin binds tightly to nucleate microtubules.  相似文献   

18.
Edwin B. Smith 《Brittonia》1982,34(4):376-380
Cardamine angustata var.ouachitana E. B. Smith, a new variety differing fromC. angustata var.angustata in absolutely glabrous leaf segments, is described from the Ouachita Mountains of Arkansas.  相似文献   

19.
This review presents the data on the role of eukaryotic-like serine/threonine protein kinases in the members of various groups of cyanobacteria. Information is provided for the two most studied model species (Anabaena and Synechocystis), differing in their morphology and ecophysiological features, and covers the entire period of study of this group of enzymes in cyanobacteria.  相似文献   

20.
A new species and genus of Choristitinae, Adventochoristites abavus gen. et sp. nov., is described from the Upper Serpukhovian of the Donets Basin and is considered as an ancestor of the Middle-Late Carboniferous Choristites linage. The characteristic features differing Alphachoristites from Choristites and Trautscholdia are specified. New species Alphachoristites berestovensis sp. nov. and Quizhouspirifer tshaikensis sp. nov. are established.  相似文献   

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