Inter-tissue variability of polytene chromosome banding patterns

1988 ◽  
Vol 4 (4) ◽  
pp. 90-91 ◽  
Author(s):  
G BEDO ◽  
A ZACHAROPOULOU
Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 598-611 ◽  
Author(s):  
D. G. Bedo

Polytene chromosome reference maps of the five autosomes of Ceratitis capitata from male pupal orbital bristle trichogen cells are presented and a correlation is established between two of them and the two largest of the five autosomes in the haploid mitotic complement. Characteristic features of each chromosome are described identifying areas that are difficult to analyze and noting the existence of common alternative band expression. A quantitative analysis of the mitotic karyotype of C. capitata indicates that the two smallest autosome pairs cannot be reliably distinguished. This may present problems with future attempts to establish homologies between the remaining mitotic and polytene chromosomes. A comparison of polytene chromosome banding patterns from salivary gland and trichogen cells failed to find any homologous regions, or even to identify homologous chromosomes. The banding differences are not explained by variation in puffing patterns, heterochromatin expression, or polyteny levels, but appear to reflect fundamental differences in banding patterns of the chromosomes in each tissue. Key words: Ceratitis capitata, polytene chromosome map, mitotic chromosome measurements.


1976 ◽  
Vol 18 (1) ◽  
pp. 85-91 ◽  
Author(s):  
T. J. Ennis

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.


Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt

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.


1974 ◽  
Vol 3 (2) ◽  
pp. 120-137 ◽  
Author(s):  
N.S.F. Ma ◽  
T.C. Jones ◽  
R.W. Thorington ◽  
R.W. Cooper

1985 ◽  
Vol 27 (4) ◽  
pp. 433-440 ◽  
Author(s):  
Ruth Phillips ◽  
Peter E. Ihssen

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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