Metaphase I chiasmata in silver-stained cores of bivalents in grasshopper spermatocytes

Genome ◽  
1987 ◽  
Vol 29 (2) ◽  
pp. 235-238 ◽  
Author(s):  
J. L. Santos ◽  
G. Ciprés ◽  
J. R. Lacadena
Keyword(s):  
Key Words ◽  
Silver Staining ◽  
Chiasma Formation ◽  
Staining Procedure ◽  
Metaphase I

Chiasmata can clearly be observed in proteinaceous scaffold-like structures in condensed metaphase I bivalents of grasshopper spermatocytes by using a highly reproducible silver-staining procedure. Origin and significance of these structures are discussed and the possibility of analyzing several topics related with chiasma formation such as distribution, interference, terminalization, or terminal associations is pointed out. Key words: scaffold, chiasma, silver staining, terminalization, Chorthippus.

Chromosome organization in meiosis revealed by light microscope analysis of silver-stained cores

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 706-712 ◽  
Author(s):  
J. S. Rufas ◽  
J. Gimenez-Abian ◽  
J. A. Suja ◽  
C. Garcia De La Vega
Keyword(s):  
Key Words ◽  
Light Microscope ◽  
Meiotic Chromosome ◽  
Chiasma Formation ◽  
Silver Impregnation ◽  
Meiotic Metaphase ◽  
Chromosome Organization ◽  
Microscope Analysis ◽  
Impregnation Technique ◽  
Metaphase I

Three species of grasshoppers have been analyzed by means of a modified silver impregnation technique that reveals the presence of a chromatid core that identifies chiasmata at first meiotic metaphase. In terms of the behaviour of the chromatid core most of the configurations observed at diplotene with orcein are easily recognized in metaphase I silver-stained bivalents. Some "hidden" configurations, as well as simple chromatin associations, that do not appear to represent chiasmata have also been detected. The disposition and behaviour of the chromatid cores in metaphase I and anaphase I provide grounds to support a reorganization of half-bivalents between first and second division. Key words: chromatid core, meiotic chromosome organization, chiasma formation, insect cytogenetics.

Nucleolar organizer activity in wheat, rye and derivatives analyzed by a silver-staining procedure

Chromosoma ◽  
1984 ◽  
Vol 89 (5) ◽  
pp. 370-376 ◽  
Author(s):  
M. C. Cerme�o ◽  
J. Orellana ◽  
J. L. Santos ◽  
J. R. Lacadena
Keyword(s):  
Silver Staining ◽  
Nucleolar Organizer ◽  
Staining Procedure ◽  
Nucleolar Organizer Activity ◽  
Organizer Activity

Selection of a silver staining procedure to detect low quantities of human epidermal ‘keratin’ protein following electrophoresis in polyacrylamide gels

1983 ◽  
Vol 127 (3) ◽  
pp. 403-406 ◽  
Author(s):  
Philip T. Bladon ◽  
Nigel F. Cooper ◽  
Ruth M. Wright ◽  
Richard A. Forster ◽  
Edward J. Wood ◽  
...  
Keyword(s):  
Silver Staining ◽  
Staining Procedure ◽  
Polyacrylamide Gels ◽  
Selection Of

Analysis of synaptonemal complexes and chromosome pairing at metaphase I in the diploid intergeneric hybrid Lolium multiflorum × Festuca drymeja

Genome ◽  
1990 ◽  
Vol 33 (4) ◽  
pp. 465-471 ◽  
Author(s):  
Hum M. Thomas ◽  
W. G. Morgan
Keyword(s):  
Chromosome Pairing ◽  
Complex Analysis ◽  
Lolium Multiflorum ◽  
Intergeneric Hybrid ◽  
Chiasma Formation ◽  
Genotypic Effect ◽  
Synaptonemal Complexes ◽  
Dna Values ◽  
Synaptonemal Complex Analysis ◽  
Metaphase I

The synaptonemal complexes in the diploid hybrid Lolium multiflorum × Festuca drymeja were examined by the surface spreading technique, and chromosome pairing at metaphase I was analysed. Synaptonemal complex analysis revealed "illegitimate" pairing, including multivalents and foldback pairing. At metaphase I, most chiasmata were between chromosomes of the same genome, and again multivalents were found. It was concluded that most synaptonemal complexes resulted in chiasma formation. The effects of the large differences in DNA values of the two species and the possible genotypic effect of F. drymeja on chromosome pairing are discussed.Key words: Lolium-Festuca, synaptonemal complexes, nonhomologous pairing, DNA values.

Undifferentiated sex chromosomes in Mastotermes darwiniensis Froggatt (Isoptera; Mastotermitidae) and the evolution of eusociality in termites

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 76-79 ◽  
Author(s):  
D. G. Bedo
Keyword(s):  
Key Words ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Mitotic Metaphase ◽  
Evolution Of Sex ◽  
Termite Species ◽  
Chromosome Differentiation ◽  
Evolution Of Eusociality ◽  
Metaphase I

Meiosis and mitosis was studied in males of the primitive termite Mastotermes darwiniensis, which is closely related to the Dictyoptera. In mitotic metaphase cells 98 chromosomes were found with a matching 49 bivalents at metaphase I. Mastotermes darwiniensis has a largely acrocentric karyotype with no sex-linked translocation complexes, like those found in many other termite species, or other sex chromosome differentiation. These observations suggest that ancestral termites probably had karyotypes with many small chromosomes lacking sex chromosome differentiation and that there is no connection between the evolution of sex-linked translocation complexes and eusociality. Key words: sex chromosomes, Mastotermes, termites, eusociality.

Genetic variability in Muscari comosum L. (Liliaceae). II. Characterization and effects of the polymorphic variants of chromosome 2 on chiasmata formation

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 695-701
Author(s):  
C. Ruiz Rejon ◽  
R. Lozano ◽  
M. Ruiz Rejon
Keyword(s):  
Genetic Variability ◽  
Key Words ◽  
Pericentric Inversion ◽  
Chromosomal Polymorphism ◽  
Chiasma Formation ◽  
The Other ◽  
Chromosome 2 ◽  
Polymorphic Variants ◽  
Insertional Translocation ◽  
Normal Pairing

Muscari comosum L. (Liliaceae) displays a striking chromosomal polymorphism in the second largest chromosome. This polymorphism involves four cosmopolitan types. Two of these are shorter than the other two homologues. One of these is submetacentric (SSM) and the other is subtelocentric (SST). The two longer types also include a submetacentric (LSM) and a subtelocentric (LST) morph. Each of the two submetacentric chromosomes has one interstitial C-band in the short arm and each of the two subtelocentric morphs has an interstitial C-band in the long arm. The change of position of this interstitial C-band is most easily explained by a pericentric inversion. Furthermore, all four types of chromosome 2 have a centromeric C-band, while the two subtelocentrics have an additional terminal C-band in the long arm. The variability in the size of the second chromosome is most likely the consequence of an unequal interchange or an insertional translocation. The meiotic behaviour of the chromosome 2 bivalents in individuals heterozygous for the pericentric inversion is characterized by normal pairing between homologues with no inversion loops, though asynapsis was present in some meiocytes. Chiasmata are absent in two regions of chromosome 2 bivalents in these heterozygotes in which they regularly form in both classes of homozygotes. In individuals heterozygous for the long morphs of chromosome 2 the bivalents again showed normal pairing at pachytene, with chiasmata again absent in some regions in which they normally form. The net result is that homozygotes have significantly higher chiasmata frequencies than hterozygotes. Key words: genetic variability, chiasma formation, Muscari.

Oil field and freshwater isolates of Shewanella putrefaciens have lipopolysaccharide polyacrylamide gel profiles characteristic of marine bacteria

1993 ◽  
Vol 39 (7) ◽  
pp. 715-717 ◽  
Author(s):  
Christopher Pickard ◽  
Julia M. Foght ◽  
Michael A. Pickard ◽  
Donald W. S. Westlake
Keyword(s):  
Marine Bacteria ◽  
Silver Staining ◽  
Gel Electrophoresis ◽  
Ferric Iron ◽  
Polyacrylamide Gel Electrophoresis ◽  
Shewanella Putrefaciens ◽  
Polyacrylamide Gel ◽  
Oil Field ◽  
Staining Procedure ◽  
Gram Negative

The lipopolysaccharide structure of oil field and freshwater isolates of bacteria that reduce ferric iron, recently classified as strains of Shewanella putrefaciens, was analyzed using polyacrylamide gel electrophoresis and a lipopolysaccharide-specific silver-staining procedure. The results demonstrate that all the oil field and freshwater isolates examined exhibited the more hydrophobic R-type lipopolysaccharide, which has been found to be characteristic of Gram-negative marine bacteria. This hydrophobic lipopolysaccharide would confer an advantage on bacteria involved in hydrocarbon degradation by assisting their association with the surface of oil droplets.Key words: lipopolysaccharide, Shewanella, aquatic bacteria, classification.

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