Ultrastructure of the plus and minus mating-type sexual agglutinins of Chlamydomonas eugametos, as visualized by negative staining

1986 ◽  
Vol 96 (1-3) ◽  
pp. 151-159 ◽  
Author(s):  
K.J. Crabbendam ◽  
F.M. Kus ◽  
A. Musgrave ◽  
H. Van Den Ends
Keyword(s):  
Mating Type ◽  
Negative Staining ◽  
Chlamydomonas Eugametos ◽  
Sexual Agglutinins

scholarly journals The sexual agglutinins in Chlamydomonas eugametos are sulphated glycoproteins

1993 ◽  
Vol 139 (4) ◽  
pp. 763-767 ◽  
Author(s):  
M. Versluis ◽  
F. M. Klis ◽  
P. Van Egmond ◽  
H. Van Den Ende
Keyword(s):  
Chlamydomonas Eugametos ◽  
Sexual Agglutinins

Composition and properties of the sexual agglutinins of the flagellated green alga Chlamydomonas eugametos

Planta ◽  
1987 ◽  
Vol 170 (3) ◽  
pp. 314-321 ◽  
Author(s):  
Marieke R. Samson ◽  
Frans M. Klis ◽  
Wieger L. Homan ◽  
Piet van Egmond ◽  
Alan Musgrave ◽  
...  
Keyword(s):  
Green Alga ◽  
Chlamydomonas Eugametos ◽  
Sexual Agglutinins

BIPARENTAL INHERITANCE OF NON-MENDELIAN GENE MARKERS IN CHLAMYDOMONAS MOEWUSII

Genetics ◽  
1986 ◽  
Vol 113 (3) ◽  
pp. 589-600
Author(s):  
Robert W Lee ◽  
Claude Lemieux
Keyword(s):  
Mating Type ◽  
Gene Mutations ◽  
Chloroplast Gene ◽  
Biparental Inheritance ◽  
Wild Type ◽  
Gene Markers ◽  
Chlamydomonas Eugametos ◽  
Mendelian Gene ◽  
Chlamydomonas Moewusii ◽  
Mode Of Transmission

ABSTRACT The first two non-Mendelian gene mutations to be identified in Chlamydomonas moewusii are described. These putative chloroplast gene mutations include one for resistance to streptomycin (sr-nM1) and one for resistance to erythromycin (er-nM1). In one- and two-factor reciprocal crosses, usually over 90% of the germinating zygospores transmitted these mutations and their wild-type alternatives from both parents (biparental zygospores); the remaining zygospores transmitted exclusively the non-Mendelian markers of the mating-type "plus" parent. Among the biparental zygospores, a strong bias in the transmission of non-Mendelian alleles from the mating-type "plus" parent was indicated by an excess of meiotic and postmeiotic mitotic progeny that were homoplasmic for non-Mendelian alleles from this parent compared to those that were homoplasmic for the non-Mendelian alleles from the mating-type "minus" parent. At best, weak linkage was detected between the sr-nM1 and er-nM1 loci. Non-Mendelian, chloroplast gene markers in Chlamydomonas eugametos and Chlamydomonas reinhardtii showed a predominantly uniparental mode of transmission from the mating-type "plus" parent in crosses performed under the same conditions used for the C. moewusii crosses.

Contact activation in Chlamydomonas gametes by increased binding capacity of sexual agglutinins

1990 ◽  
Vol 95 (2) ◽  
pp. 293-301
Author(s):  
A. M. TOMSON ◽  
R. DEMETS ◽  
A. MUSGRAVE ◽  
R. KOOIJMAN ◽  
D. STEGWEE ◽  
...  
Keyword(s):  
Adhesion Molecules ◽  
Wheat Germ Agglutinin ◽  
Wheat Germ ◽  
Binding Capacity ◽  
Contact Activation ◽  
Chlamydomonas Eugametos ◽  
Sexual Agglutinins

When the flagella of compatible gametes of Chlamydomonas eugametos contact one another, the capacity for sexual adhesion is rapidly increased. It is shown that during this so-called contact activation the amount of adhesion molecules, or agglutinins, on the flagellar surface remains relatively constant, indicating that the increase in sexual adhesiveness is mainly the result of an enhancement in binding capacity of the agglutinins. Contact activation coincides with an apparent aggregation of agglutinins in association with a weakening of the agglutinin binding to the membrane. Artificial clustering of the agglutinins, using the lectin wheat germ agglutinin, also leads to an increase in sexual adhesiveness. In the presence of anti-tubulin drugs compatible gametes make contact with one another but fail to increase their adhesiveness. It is proposed that micro-aggregation of agglutinin molecules, mediated by tubulin, underlies the enhancement of sexual binding capacity.

Polymer Morphology Revealed by Staining Techniques

1981 ◽  
Vol 39 ◽  
pp. 340-341
Author(s):  
A. C. Reimschuessel ◽  
V. Kramer
Keyword(s):  
Polymer Melt ◽  
Nylon 6 ◽  
Morphological Features ◽  
Negative Staining ◽  
Polymer Morphology ◽  
Crystallizable Polymer ◽  
Staining Techniques ◽  
Long Chain

Staining techniques can be used for either the identification of different polymers or for the differentiation of specific morphological domains within a given polymer. To reveal morphological features in nylon 6, we choose a technique based upon diffusion of the staining agent into accessible regions of the polymer.When a crystallizable polymer - such as nylon 6 - is cooled from the melt, lamellae form by chainfolding of the crystallizing long chain macromolecules. The regions between adjacent lamellae represent the less ordered amorphous domains into which stain can diffuse. In this process the lamellae will be “outlined” by the dense stain, giving rise to contrast comparable to that obtained by “negative” staining techniques.If the cooling of the polymer melt proceeds relatively slowly - as in molding operations - the lamellae are usually arranged in a radial manner. This morphology is referred to as spherulitic.

New ultrastructural findings about Borrelia burgdorferi by cryofixation, negative staining, thin sectioning and scanning techniques

1990 ◽  
Vol 48 (3) ◽  
pp. 582-583
Author(s):  
S. F. Hayes ◽  
M. D. Corwin ◽  
T. G. Schwan ◽  
D. W. Dorward ◽  
W. Burgdorfer
Keyword(s):  
Lyme Disease ◽  
Borrelia Burgdorferi ◽  
Structural Characterization ◽  
Negative Staining ◽  
Low Speed ◽  
Thin Sectioning ◽  
Ultrastructural Findings

Characterization of Borrelia burgdorferi strains by means of negative staining EM has become an integral part of many studies related to the biology of the Lyme disease organism. However, relying solely upon negative staining to compare new isolates with prototype B31 or other borreliae is often unsatisfactory. To obtain more satisfactory results, we have relied upon a correlative approach encompassing a variety EM techniques, i.e., scanning for topographical features and cryotomy, negative staining and thin sectioning to provide a more complete structural characterization of B. burgdorferi.For characterization, isolates of B. burgdorferi were cultured in BSK II media from which they were removed by low speed centrifugation. The sedimented borrelia were carefully resuspended in stabilizing buffer so as to preserve their features for scanning and negative staining. Alternatively, others were prepared for conventional thin sectioning and for cryotomy using modified procedures. For thin sectioning, the fixative described by Ito, et al.

Development of a PCR assay for amplification of mating-type loci of Alternaria spp. and related fungi.

2013 ◽  
Vol 65 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Philipp B. Gannibal ◽  
Igor A. Kazartsev
Keyword(s):  
Mating Type ◽  
Pcr Assay
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