CHROMOSOME STRUCTURE IN CHILOCORUS (COLEOPTERA: COCCINELLIDAE). II. THE ASYNCHRONOUS REPLICATION OF CONSTITUTIVE HETEROCHROMATIN

1976 ◽  
Vol 18 (1) ◽  
pp. 85-91 ◽  
Author(s):  
T. J. Ennis
Keyword(s):  
Chromosome Banding ◽  
Chromosome Structure ◽  
Constitutive Heterochromatin ◽  
Chromosome Replication ◽  
Data Models ◽  
Late Replication ◽  
Banding Patterns ◽  
Asynchronous Replication ◽  
Chilocorus Stigma

Chromosome replication has been analysed in four species of Chilocorus. In C. orbus Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic (= diphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic arm (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only.

FLUORESCENT PROBES OF CHROMOSOME STRUCTURE AND REPLICATION

1977 ◽  
Vol 19 (4) ◽  
pp. 603-623 ◽  
Author(s):  
Samuel A. Latt
Keyword(s):  
Chromosome Banding ◽  
Chromosome Structure ◽  
Fluorescent Dyes ◽  
Close Association ◽  
Replication Timing ◽  
Brdu Incorporation ◽  
Metaphase Chromosomes ◽  
Banding Patterns ◽  
Chemical Studies ◽  
Chromosome Staining

Procedures employing fluorescent dyes or Giemsa stain have been utilized to differentiate metaphase chromosomes into longitudinal segments termed bands. In spite of the immense practical utility of chromosome banding, the chemical basis of banding patterns remains incompletely understood. Physical chemical studies have elucidated the modes and specificities of the interaction of fluorescent dyes such as quinacrine, 33258 Hoechst, daunomycin, chromomycin A3 and 7-aminoactinomycin D with DNA and chromatin. However, it is not clear that all aspects of chromosome staining are explainable in terms of the optical properties of soluble dye-DNA complexes. BrdU-dye techniques in which chromosome staining depends on the schedule of BrdU incorporation by cells, have been used for cytological studies of chromosome structure and replication. These procedures have revealed a close association between quinacrine or Giemsa bands and late replicating chromosomal regions. Biochemical studies on chromatin differentially labelled according to replication timing may thus prove useful for investigating the molecular basis of chromosome banding.

DIFFERENTIAL GIEMSA STAINING IN PLANTS. V. TWO TYPES OF CONSTITUTIVE HETEROCHROMATIN IN SPECIES OF AVENA

1977 ◽  
Vol 19 (4) ◽  
pp. 739-743 ◽  
Author(s):  
Sheng-Tian Yen ◽  
W. Gary Filion
Keyword(s):  
Room Temperature ◽  
Chromosome Banding ◽  
Constitutive Heterochromatin ◽  
Diploid Species ◽  
The Other ◽  
Giemsa Staining ◽  
Barium Hydroxide ◽  
Giemsa Banding ◽  
Banding Patterns ◽  
Hydrolysis Temperature

Modified ASG (Acetic/Saline/Giemsa) and BSG (Barium hydroxide/Saline/Giemsa) chromosome banding techniques applied to several diploid species of oats produced two distinct types of C-banding patterns. One pattern consisted mainly of centromeric bands with occasional telomeric and/or intercalary bands while the other was comprised only of prominent telomeric and intercalary bands. These two banding patterns which probably reflect two distinct types of constitutive heterochromatin resulted from a change in the HCl hydrolysis temperature prior to the application of the ASG or BSG technique; hydrolysis at 60 °C yielded the centromeric bands and hydrolysis at room temperature produced telomeric and intercalary bands. Since all species examined reacted in a similar manner, precise Giemsa banding patterns should now be possible for all or most species of oats.

Rye C-banding patterns and meiotic stability of hexaploid triticale (× Triticosecale) selections differing in kernel shriveling

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt
Keyword(s):  
Secale Cereale ◽  
Chromosome Banding ◽  
Agronomic Performance ◽  
Hexaploid Triticale ◽  
Kernel Development ◽  
Banding Patterns ◽  
C Banding ◽  
Meiotic Stability ◽  
Metaphase I

Two winter hexaploid triticale populations derived from the same cross were selected on the basis of grain appearance and agronomic performance. The five lines from 84LT402 showed more kernel shriveling than the four lines from 84LT401. The derived lines were analyzed for aneuploid frequencies, rye chromosome banding patterns, and meiotic stability to detect associations with kernel development. The aneuploid frequencies were 16% in 84LT401 and 18% in 84LT402. C-banding showed that both selection groups had all the rye chromosomes except 2R. The two groups had similar telomeric patterns but differed in the long-arm interstitial patterns of 4R and 5R. Compared with lines from 84LT402, those from 84LT401 had significantly fewer univalents and rod bivalents, and more paired arms at metaphase I; fewer laggards and bridges at anaphase I; and a higher frequency of normal tetrads. There were no significant differences among lines within each group for any meiotic character. Since there were no differences within or between groups in telomeric banding patterns, the differences in kernel shriveling and meiotic stability might be due to genotypic factors and (or) differences in the interstitial patterns of 4R and 5R. By selecting plump grains, lines with improved kernel characteristics along with improved meiotic stability are obtainable.Key words: triticale, meiotic stability, C-banding, Secale cereale, heterochromatin.

Chromosome Banding Patterns in Squirrel Monkeys (Saimiri sciureus)

1974 ◽  
Vol 3 (2) ◽  
pp. 120-137 ◽  
Author(s):  
N.S.F. Ma ◽  
T.C. Jones ◽  
R.W. Thorington ◽  
R.W. Cooper
Keyword(s):  
Chromosome Banding ◽  
Squirrel Monkeys ◽  
Saimiri Sciureus ◽  
Banding Patterns

Chromosome banding in salmonid fish: nucleolar organizer regions in Salmo and Salvelinus

1985 ◽  
Vol 27 (4) ◽  
pp. 433-440 ◽  
Author(s):  
Ruth Phillips ◽  
Peter E. Ihssen
Keyword(s):  
Atlantic Salmon ◽  
Brown Trout ◽  
Brook Trout ◽  
Chromosome Banding ◽  
Lake Trout ◽  
Nucleolar Organizer ◽  
Nucleolar Organizer Regions ◽  
Banding Patterns ◽  
Single Chromosome ◽  
Secondary Constrictions

Chromosome banding patterns obtained by silver staining (Ag-NORs) were analyzed in three species of Salmo (rainbow, brown trout, and Atlantic salmon) and three species of Salvelinus (brook trout, lake trout, and arctic char). In rainbow trout and Atlantic salmon the Ag-NORs were found at the secondary constrictions of a single chromosome pair, while in brown trout the Ag-NORs were found on the short arms of one or two of the two longest subtelocentric or acrocentric chromosome pairs. The location of the Ag-NORs was multichromosomal in the three Salvelinus species, occurring on one or both members of four to six different chromosome pairs in different individuals. The Ag-NOR sites were on the short arms of some acrocentric pairs and at the telomeres of other acrocentric pairs and one or two metacentric pairs. Chromomycin A3 positive bands were found at the same sites as the Ag-NORs in all species. In the species with multichromosomal location of Ag-NORs, polymorphisms in the size and location of the NORs were extremely common, so that almost every individual fish had a different pattern of Ag-NOR sites.Key words: banding, Salmo, Salvelinus, Ag-NORs, polymorphisms, nucleolar organizer.

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