A NEW FIXATIVE AND IMPROVED PROPIONOCARMINE SQUASH TECHNIQUE FOR STAINING FUNGUS NUCLEI

1962 ◽  
Vol 40 (6) ◽  
pp. 843-847 ◽  
Author(s):  
Benjamin C. Lu
Keyword(s):  
Acetic Acid ◽  
Neurospora Crassa ◽  
Nuclear Division ◽  
Chromic Acid ◽  
Butyl Alcohol ◽  
Sexual Stage ◽  
Mitotic Figures ◽  
Improved Technique ◽  
Germ Tubes

A new fixative, which is composed of butyl alcohol, acetic acid, and chromic acid, is introduced. This BAC mixture fixes nuclear details, and cytoplasm is not granulated to any extent. Details of staining procedures and helpful hints for successful staining are given. This improved technique differentiates all stages of nuclear division from interphase to interphase in the vegetative hyphae of fungi as well as in the sexual stage. Chromosomes, nucleoli, and centrioles are clearly shown. A series of mitotic figures in germ tubes of Neurospora crassa and some meiotic figures in Gelasinospora calospora are attached as illustrations.

HSCCC Separation of Three Main Compounds from the Crude Extract of Dracocephalum Tanguticum by Using Dimethyl Sulfoxide as Cosolvent

2020 ◽  
Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Efficient Method ◽  
Crude Extract ◽  
High Speed ◽  
Glacial Acetic Acid ◽  
Butyl Alcohol ◽  
Preparative Hplc ◽  
Counter Current

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.

scholarly journals Cell Biology of Conidial Anastomosis Tubes in Neurospora crassa

2005 ◽  
Vol 4 (5) ◽  
pp. 911-919 ◽  
Author(s):  
M. Gabriela Roca ◽  
Jochen Arlt ◽  
Chris E. Jeffree ◽  
Nick D. Read
Keyword(s):  
Neurospora Crassa ◽  
Optical Tweezers ◽  
Cell Biology ◽  
Transmembrane Protein ◽  
Mitogen Activated Protein Kinase ◽  
Cellular Element ◽  
Hyphal Fusion ◽  
Self Recognition ◽  
Mitogen Activated Protein ◽  
Germ Tubes

ABSTRACT Although hyphal fusion has been well documented in mature colonies of filamentous fungi, it has been little studied during colony establishment. Here we show that specialized hyphae, called conidial anastomosis tubes (CATs), are produced by all types of conidia and by conidial germ tubes of Neurospora crassa. The CAT is shown to be a cellular element that is morphologically and physiologically distinct from a germ tube and under separate genetic control. In contrast to germ tubes, CATs are thinner, shorter, lack branches, exhibit determinate growth, and home toward each other. Evidence for an extracellular CAT inducer derived from conidia was obtained because CAT formation was reduced at low conidial concentrations. A cr-1 mutant lacking cyclic AMP (cAMP) produced CATs, indicating that the inducer is not cAMP. Evidence that the transduction of the CAT inducer signal involves a putative transmembrane protein (HAM-2) and the MAK-2 and NRC-1 proteins of a mitogen-activated protein kinase signaling pathway was obtained because ham-2, mak-2, and nrc-1 mutants lacked CATs. Optical tweezers were used in a novel experimental assay to micromanipulate whole conidia and germlings to analyze chemoattraction between CATs during homing. Strains of the same and opposite mating type were shown to home toward each other. The cr-1 mutant also underwent normal homing, indicating that cAMP is not the chemoattractant. ham-2, mak-2, and nrc-1 macroconidia did not attract CATs of the wild type. Fusion between CATs of opposite mating types was partially inhibited, providing evidence of non-self-recognition prior to fusion. Microtubules and nuclei passed through fused CATs.

A Direct Determination of Rubber Hydrocarbon. Chromic Acid Oxidation Method

1943 ◽  
Vol 16 (3) ◽  
pp. 660-667 ◽  
Author(s):  
V. L. Burger ◽  
W. E. Donaldson ◽  
J. A. Baty
Keyword(s):  
Acetic Acid ◽  
Chromic Acid ◽  
Direct Determination ◽  
Acid Oxidation ◽  
Laboratory Procedure ◽  
Oxidation Method ◽  
Chromic Acid Oxidation

Abstract A method for the direct determination of rubber is reported. This method utilizes the property of rubber hydrocarbon when oxidized by chromic acid to form definite and reproducible amounts of acetic acid. This determination has been reduced to a comparatively simple laboratory procedure, whose accuracy (in the absence of interferences) is 1 to 2 per cent.

SOME OXIDATION REACTIONS OF DELCOSINE

1957 ◽  
Vol 35 (4) ◽  
pp. 397-408 ◽  
Author(s):  
Ragini Anet ◽  
D. W. Clayton ◽  
Léo Marion
Keyword(s):  
Acetic Acid ◽  
Silver Oxide ◽  
Chromic Acid ◽  
Mercuric Acetate ◽  
Membered Ring ◽  
Oxidation Reactions ◽  
Ethyl Group ◽  
Compound C ◽  
Ring Oxidation ◽  
Group B

The alkaloid delcosine was oxidized by chromic acid in acetic acid, and also by the Oppenauer reaction, to dehydrodelcosine in which the carbonyl was shown by infrared absorption to be in a pentatomic ring. Oxidation of the alkaloid with silver oxide gave two products: (a) N-desethyldelcosine, which could be N-acetylated or converted back to the original base by ethylation, thus proving the presence of an N-ethyl group; (b) a compound, C24H37O7N, the properties of which agreed best with those of an internal ether, i.e., anhydrohydroxydelcosine. The action of N-bromosuccinimide on the alkaloid produced the same two compounds as silver oxide, plus a derivative, C22H33O7N, that proved to be N-desethyl-anhydrohydroxydelcosine. Potassium permanganate oxidized delcosine to a product, C22H31O7N, that had lost the N-ethyl group, contained the internal ether, and also a carbonyl in a five-membered ring. This same product was obtained on similar oxidation of N-desethyl-anhydrohydroxydelcosine. Oxidation of delcosine with mercuric acetate gave N-desethyldelcosine and N-desethyl-anhydrohydroxydelcosine, together with a compound that was very soluble in water and proved to be the carbinolamine formed by hydroxylation of the methylene in the N-ethyl group. These results are discussed in terms of a structure that is tentatively advanced for delcosine.

Conversion of DDT and Its Metabolites to Dichlorobenzophenones for Analysis in the Presence of Polychlorinated Biphenyls

1972 ◽  
Vol 55 (5) ◽  
pp. 1039-1041
Author(s):  
J R W Miles
Keyword(s):  
Acetic Acid ◽  
Polychlorinated Biphenyls ◽  
Chromic Acid ◽  
Hexane Fraction ◽  
Convenient Technique

Abstract The separation of DDT compounds from interfering polychlorinated biphenyls (PCB) has been effected by oxidation of DDE and DDMU (l-chloro-2,2-bis(p-chlorophenyl)ethylene) to the more polar dichlorobenzophenone. DDT and DDD (o,p’ - and p,p’-) are dehydrochlorinated by a convenient technique, utilizing l,5-diazobicyclo[5.4.0]undec-5-ene, and the resulting olefins are oxidized by chromic acid in acetic acid. In subsequent Florisil fractionation, the interfering PCB compounds, relatively unchanged by the dehydrochlorination and oxidation, are eluted in the hexane fraction, while the dichlorobenzophenones are eluted by benzene. Recoveries of p,p’-DDE and p,p’-DDT added to fish extracts at 5 ppm each were 82.5±2.1 and 86.0±2.2%, respectively.

scholarly journals Regulation of Pathogenic Spore Germination by CgRac1 in the Fungal Plant Pathogen Colletotrichum gloeosporioides

2011 ◽  
Vol 10 (8) ◽  
pp. 1122-1130 ◽  
Author(s):  
Iris Nesher ◽  
Anna Minz ◽  
Leonie Kokkelink ◽  
Paul Tudzynski ◽  
Amir Sharon
Keyword(s):  
Cell Division ◽  
Plant Pathogen ◽  
Germ Tube ◽  
Colletotrichum Gloeosporioides ◽  
Fluorescent Protein ◽  
Nuclear Division ◽  
Simultaneous Formation ◽  
Content Type ◽  
Germ Tubes

ABSTRACT Colletotrichum gloeosporioides is a facultative plant pathogen: it can live as a saprophyte on dead organic matter or as a pathogen on a host plant. Different patterns of conidial germination have been recognized under saprophytic and pathogenic conditions, which also determine later development. Here we describe the role of CgRac1 in regulating pathogenic germination. The hallmark of pathogenic germination is unilateral formation of a single germ tube following the first cell division. However, transgenic strains expressing a constitutively active CgRac1 (CA-CgRac1) displayed simultaneous formation of two germ tubes, with nuclei continuing to divide in both cells after the first cell division. CA-CgRac1 also caused various other abnormalities, including difficulties in establishing and maintaining cell polarity, reduced conidial and hyphal adhesion, and formation of immature appressoria. Consequently, CA-CgRac1 isolates were completely nonpathogenic. Localization studies with cyan fluorescent protein (CFP)-CgRac1 fusion protein showed that the CgRac1 protein is abundant in conidia and in hyphal tips. Although the CFP signal was equally distributed in both cells of a germinating conidium, reactive oxygen species accumulated only in the cell that produced a germ tube, indicating that CgRac1 was active only in the germinating cell. Collectively, our results show that CgRac1 is a major regulator of asymmetric development and that it is involved in the regulation of both morphogenesis and nuclear division. Modification of CgRac1 activity disrupts the morphogenetic program and prevents fungal infection.

scholarly journals F-Actin Dynamics in Neurospora crassa

2010 ◽  
Vol 9 (4) ◽  
pp. 547-557 ◽  
Author(s):  
Adokiye Berepiki ◽  
Alexander Lichius ◽  
Jun-Ya Shoji ◽  
Jens Tilsner ◽  
Nick D. Read
Keyword(s):  
Neurospora Crassa ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Protein ◽  
Live Cell ◽  
Actin Dynamics ◽  
Actin Binding ◽  
Content Type ◽  
Actin Cables ◽  
Germ Tubes

ABSTRACT This study demonstrates the utility of Lifeact for the investigation of actin dynamics in Neurospora crassa and also represents the first report of simultaneous live-cell imaging of the actin and microtubule cytoskeletons in filamentous fungi. Lifeact is a 17-amino-acid peptide derived from the nonessential Saccharomyces cerevisiae actin-binding protein Abp140p. Fused to green fluorescent protein (GFP) or red fluorescent protein (TagRFP), Lifeact allowed live-cell imaging of actin patches, cables, and rings in N. crassa without interfering with cellular functions. Actin cables and patches localized to sites of active growth during the establishment and maintenance of cell polarity in germ tubes and conidial anastomosis tubes (CATs). Recurrent phases of formation and retrograde movement of complex arrays of actin cables were observed at growing tips of germ tubes and CATs. Two populations of actin patches exhibiting slow and fast movement were distinguished, and rapid (1.2 μm/s) saltatory transport of patches along cables was observed. Actin cables accumulated and subsequently condensed into actin rings associated with septum formation. F-actin organization was markedly different in the tip regions of mature hyphae and in germ tubes. Only mature hyphae displayed a subapical collar of actin patches and a concentration of F-actin within the core of the Spitzenkörper. Coexpression of Lifeact-TagRFP and β-tubulin–GFP revealed distinct but interrelated localization patterns of F-actin and microtubules during the initiation and maintenance of tip growth.

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