BrdU replication bands in the anguilliform fishEchelus myrus

1995 ◽  
Vol 3 (7) ◽  
pp. 423-426 ◽  
Author(s):  
A. Amores ◽  
J. Bejar ◽  
M. C. Alvarez
Keyword(s):  
Replication Bands

scholarly journals COMPARTMENTALIZATION OF THE DEVELOPING MACRONUCLEUS FOLLOWING CONJUGATION IN STYLONYCHIA AND EUPLOTES

1970 ◽  
Vol 47 (2) ◽  
pp. 395-407 ◽  
Author(s):  
John A. Kloetzel
Keyword(s):  
Electron Microscope ◽  
Fibrous Material ◽  
Polytene Chromosomes ◽  
Genetic Constitution ◽  
Thin Sections ◽  
Macronuclear Development ◽  
Individual Bands ◽  
Second Period ◽  
Replication Bands ◽  
Material Form

The development of the macronucleus following conjugation in the hypotrichous ciliates Euplotes and Stylonychia has been examined with the electron microscope. Banded polytene chromosomes can be seen in thin sections of the macronuclear anlagen during the early periods of exconjugant development. As the chromosomes reach their maximum state of polyteny, sheets of fibrous material appear between the chromosomes and transect the chromosomes in the interband regions. Individual bands of the polytene chromosomes thus appear to be isolated in separate compartments. Subsequently, during the stage when the bulk of the polytenic DNA is degraded (1), these compartments swell, resulting in a nucleus packed with thousands of separate spherical chambers. Individual chromosomes are no longer discernible. The anlagen retain this compartmentalized condition for several hours, at the end of which time aggregates of dense material form within many of the compartments. The partitioning layers disperse shortly before replication bands appear within the elongating anlagen, initiating the second period of DNA synthesis characteristic of macronuclear development in these hypotrichs. The evidence presented here suggests that the "chromatin granules" seen in the mature vegetative macronucleus represent the material of single bands of the polytene chromosomes seen during the earlier stages of macronuclear development. The possibility is also discussed that the degradation of DNA in the polytene chromosomes may be genetically selective, which would result in a somatic macronucleus with a different genetic constitution than that of the micronucleus from which it was derived.

scholarly journals Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae)

2015 ◽  
Vol 145 (3-4) ◽  
pp. 201-217 ◽  
Author(s):  
Michael Schmid ◽  
Claus Steinlein
Keyword(s):  
Chromosome Pair ◽  
Repetitive Sequences ◽  
5S Rdna ◽  
Mitotic Chromosomes ◽  
Banding Patterns ◽  
Single Chromosome ◽  
Replication Banding ◽  
Rdna Sequences ◽  
High Degree ◽  
Replication Bands

Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.

Relation between the SCE points and the DNA replication bands

Chromosoma ◽  
1979 ◽  
Vol 73 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Joe J. Hoo ◽  
Malcolm I. Parslow
Keyword(s):  
Dna Replication ◽  
Replication Bands

scholarly journals Proliferating cell nuclear antigen/cyclin in the ciliate Euplotes eurystomus: localization in the replication band and in micronuclei.

1989 ◽  
Vol 109 (4) ◽  
pp. 1399-1410 ◽  
Author(s):  
D E Olins ◽  
A L Olins ◽  
L H Cacheiro ◽  
E M Tan
Keyword(s):  
Dna Polymerase ◽  
Proliferating Cell Nuclear Antigen ◽  
Culture Conditions ◽  
Nuclear Antigen ◽  
Ciliated Protozoa ◽  
Dna Polymerase Delta ◽  
Replication Band ◽  
Auxiliary Protein ◽  
Proliferating Cell ◽  
Replication Bands

Human autoimmune sera specific for proliferating cell nuclear antigen (PCNA)/cyclin (auxiliary protein for DNA polymerase delta) demonstrated the presence of epitopes within the macro- and micronuclei of the hypotrichous ciliated protozoa Euplotes eurystomus. Tightly bound PCNA/cyclin was localized at the site of DNA synthesis in macronuclei, the rear zone of the replication band. Starvation or heat shock, conditions that reduce macronuclear replication, resulted in a decrease of PCNA/cyclin in replication bands. Micronuclei also exhibited PCNA/cyclin localization which persisted for a large proportion of the vegetative cell cycle and exhibited significant resistance to adverse culture conditions. Immunoprecipitation of 35S-labeled soluble Euplotes proteins with PCNA/cyclin autoimmune sera revealed a spectrum of low molecular mass proteins. PCNA/cyclin-like proteins have now been observed in the widely divergent species: human, rat, amphibian, yeast, and ciliated protozoa.

Occurrence of two cytotypes in Bryconamericus aff. iheringii (Characidae): karyotype analysis by C- and G-banding and replication bands

Genetica ◽  
2007 ◽  
Vol 133 (2) ◽  
pp. 113-118 ◽  
Author(s):  
Ana Luiza de Brito Portela-Castro ◽  
Horácio Ferreira Julio ◽  
Isabel Cristina Martins dos Santos ◽  
Carla Simone Pavanelli
Keyword(s):  
Karyotype Analysis ◽  
Replication Bands

Lectin-like components in the macronuclear replication bands of Euplotes eurystomus

1988 ◽  
Vol 62 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Donald E. Olins ◽  
Ada L. Olins ◽  
Annie-Pierre Sève ◽  
Claire A. Bourgeois ◽  
Jean Hubert ◽  
...  
Keyword(s):  
Replication Bands

scholarly journals Examination of the macronuclear replication band in Euplotes eurystomus with monoclonal antibodies.

1986 ◽  
Vol 102 (1) ◽  
pp. 131-136 ◽  
Author(s):  
R L Allen ◽  
S J Kennel ◽  
L Cacheiro ◽  
A L Olins ◽  
D E Olins
Keyword(s):  
Monoclonal Antibodies ◽  
Solid Phase ◽  
Spleen Cells ◽  
Sds Page ◽  
Replication Band ◽  
Degradative Enzymes ◽  
Specific Proteins ◽  
Solid Phase Radioimmunoassay ◽  
Replication Bands ◽  
Immunofluorescence Antibody

A panel of eight monoclonal antibodies (MAbs) was prepared from spleen cells of mice immunized with macronuclear replication bands (RBs) isolated from Euplotes eurystomus. Antibodies were investigated with a solid phase radioimmunoassay (RIA) using either soluble chromatin from isolated RBs or from total macronuclei as antigen. The RIA showed that several MAbs recognized antigens present only in the RB or macronucleus, whereas others recognized antigens present in both structures. Specificity of the MAbs was also examined by indirect immunofluorescence. Antibody C10 recognized an antigen in the rear zone of the RB, whereas MAbs G6 and B2 appeared to stain both the forward and rear zones of the RB. Antibody A7 recognized an epitope distributed throughout the macronucleus except in the RB. Cytochemical studies with degradative enzymes suggested that antigens localized by immunofluorescence were composed of proteins. Immunoblots of SDS PAGE permitted identification of a few proteins that reacted with three of the RB-specific MAbs. Monoclonal antibodies that identify the presence or absence of reactivity of specific proteins in the RB could prove useful in the study of chromatin structure and the mechanism of chromatin replication.

Replication bands and nucleoli in the macronucleus of Euplotes eurystomus: An ultrastructural and cytochemical study

1988 ◽  
Vol 62 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Ada L. Olins ◽  
Donald E. Olins ◽  
Massimo Derenzini ◽  
Danièle Hernandez-Verdun ◽  
Pierre Gounon ◽  
...  
Keyword(s):  
Cytochemical Study ◽  
Replication Bands
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