C-banding and DNA content in three species of Belostoma (Heteroptera) with large differences in chromosome size and number

Genetica ◽  
1988 ◽  
Vol 76 (1) ◽  
pp. 43-51 ◽  
Author(s):  
A. G. Papeschi
Genome ◽  
1988 ◽  
Vol 30 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Daniel de Azkue ◽  
Arturo Martínez

The amount of DNA varies widely in 20 shrubby Oxalis species analyzed, ranging from 1.76 pg in O. alstonii to 33.00 pg in O. dispar. This wide variation in DNA content coincided with a wide variation in chromosome size and shape. Numerical taxonomy methods showed that this variation in chromosome size and shape in shrubby Oxalis is mainly due to extra DNA. It was also possible to arrange the 20 species examined in six different groups on the basis of karyotypic similarities.Key words: Oxalis, DNA content, chromosome evolution, multivariate analysis.


1985 ◽  
Vol 27 (6) ◽  
pp. 766-775 ◽  
Author(s):  
Arturo Martínez ◽  
Héctor D. Ginzo

There is a wide variation in the nuclear DNA content and chromosome size between the species belonging to the T. crassifolia and T. virginiana alliances (all the species but one are native to Central and North America). Also the DNA content per genome decreases when the ploidy level increases within the same specific polyploid complex with three ploidy levels (2x, 4x, and 6x). In contrast, no variation was found in the DNA content per genome between different ploidy levels in the T. fluminensis alliance (all the species are native to South America) where they range from 6x to 22x. Since all the species described here are perennials with various life forms, it was possible to analyze the relationship between the DNA content and their vegetative adaptation to the environment. The more specialized species (geophytes and hemicryptophytes) have a higher amount of DNA than the chamaephytes adapted to live in relatively more mesic regions. In the species living in Central and North America there is a positive correlation between the increase in DNA content and the latitude of their native regions.Key words: Tradescantia, DNA content, geographical distribution, life forms, polyploidy.


Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 834-839 ◽  
Author(s):  
C. Juan ◽  
E. Petitpierre

The relative amount of C-banded heterochromatin varies strikingly in seven species of tenebrionid beetles, from 25 to 58%, but most species show procentric bands only. Nevertheless, Gonocephalum patruele exhibits an almost completely heterochromatic X chromosome. The nuclear DNA content of Feulgen-stained spermatids has yielded up to a threefold difference, from 0.27 to 0.86 pg, which is not completely in accordance with the amount of C-banded heterochromatin. However, the genome sizes correlate significantly with the total chromosome areas at metaphase I and with the spermatid areas. Furthermore, the genome sizes agree with the subfamilial taxonomic groupings of these tenebrionids.Key words: Tenebrionidae, genome size, C-banding.


Chromosoma ◽  
1966 ◽  
Vol 20 (1) ◽  
pp. 54-74 ◽  
Author(s):  
Klaus Rothfels ◽  
Elizabeth Sexsmith ◽  
Margaret Heimburger ◽  
Margarida O. Krause
Keyword(s):  

1969 ◽  
Vol 13 (3) ◽  
pp. 241-250 ◽  
Author(s):  
G. J. Dowrick ◽  
A. S. El Bayoumi

1. The DNA contents of twenty-eight different species and forms of Chrysanthemum have been measured by photometry. It is shown that there are large differences in DNA content between some species with identical chromosome numbers.2. The DNA contents of natural polyploids are frequently not those expected when comparison is made with diploid forms of the same species. The DNA contents of induced polyploids are those expected.3. Chromosome length and volume are positively correlated with DNA content.4. The relationship between chromosome number, chromosome size, DNA content and gene number is considered, and it is suggested that the differences in DNA content may result from the presence of differing amounts of genetically inactive DNA in the chromosomes.


Caryologia ◽  
1973 ◽  
Vol 26 (2) ◽  
pp. 263-273 ◽  
Author(s):  
L. Janette Taper ◽  
W. F. Grant

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 258-265 ◽  
Author(s):  
I. Galasso ◽  
D. Pignone ◽  
M. Frediani ◽  
M. Maggiani ◽  
R. Cremonini

The karyotypes of three accessions, one each from three annual species of the genus Cicer, namely Cicer arietinum, Cicer reticulation, and Cicer echinospermum, were examined and compared using C-banding, the fluorochromes chromomycin A3, DAPI, and Hoechst 33258, in situ hybridization of the 18S–5.8S–25S and 5S rDNA sequences, and silver staining. The nuclear DNA content of the three species and the amount of heterochromatin were also determined. The results suggest an evolutionary pathway in which C. reticulatum is the ancestral species from which both C. arietinum and C. echinospermum are derived with the loss of one pair of satellites; subsequently, C. echinospermum further differentiated by the accumulation of chromosomal rearrangement(s) that gave rise to a hybrid sterility barrier. Key words : Cicer, C-banding, fluorochromes, Ag staining, rRNA genes.


1979 ◽  
Vol 21 (3) ◽  
pp. 367-372 ◽  
Author(s):  
G. Allan Edwards ◽  
M. Anwar Mirza

Gossypium bickii Prokh. is distinct from the C genome species, although it was tentatively placed in this genome. A comparison of the karyotypes of G. bickii and G. sturtianum Willis separates G. bickii sharply from G. sturtianum, the standard species for the C genome. Karyotypic differences are evident in centromere position of the chromosomes, chromosome size, and the lack of satellites or secondary constrictions in G. bickii. A clear separation of G. bickii from G. sturtianum and other Gossypium species is also demonstrated in previous studies of phenetic analysis, flower flavonoids, DNA content, and electrophoresis of seed proteins, esterases, leucine aminopeptidases, and catalases. G. bickii is placed in a new G genome and is assigned to the 2G1 subgenome.


1986 ◽  
Vol 28 (6) ◽  
pp. 921-925 ◽  
Author(s):  
W. G. Morgan ◽  
Hugh Thomas ◽  
M. Evans ◽  
M. Borrill

Chromosome pairing in hybrids between diploid species of Festuca is described. The chromosome complements of the species from different taxonomic sections vary in chromosome size and DNA content. In interspecific hybrids involving species of the section Montanae there was a relationship between the difference in DNA content of the parental species and chromosome pairing in the F1 hybrids. The larger the difference between the DNA content of the parental species, the more pronounced the failure of chromosome pairing in the F1 hybrids. Factors other than divergence in genome size were also shown to have an effect on chromosome pairing in other hybrid combinations.Key words: chromosome pairing, DNA content, Festuca, hybrids (interspecific).


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