Karyotypic conservatism in the genus Lepus (order Lagomorpha)

1983 ◽  
Vol 25 (5) ◽  
pp. 540-544 ◽  
Author(s):  
T. J. Robinson ◽  
F. F. B. Elder ◽  
J. A. Chapman
Keyword(s):  
Banding Pattern ◽  
Chromosome Morphology ◽  
Karyotypic Change

The G- and C-banded chromosomes of six species of hare (genus Lepus) are presented and compared. No variation in gross chromosome morphology or banding pattern was observed indicating that speciation in this widespread genus has not involved karyotypic change.

BANDING STUDIES IN THE VOLCANO RABBIT, ROMEROLAGUS DIAZI AND CRAWSHAY'S HARE LEPUS CRAWSHAYI. EVIDENCE OF THE LEPORID ANCESTRAL KARYOTYPE

1981 ◽  
Vol 23 (3) ◽  
pp. 469-474 ◽  
Author(s):  
T. J. Robinson ◽  
Frederick F. B. Elder ◽  
W. Lopez-Forment
Keyword(s):  
North American ◽  
Banding Pattern ◽  
Constitutive Heterochromatin ◽  
Chromosome Morphology ◽  
Evolutionary Origin ◽  
Ancestral Karyotype ◽  
Remarkable Similarity ◽  
Common Evolutionary Origin ◽  
The North

G- and C-banded karyotypes are presented for the North American volcano rabbit, Romerolagus diazi (Ferrari-Perez, 1893) and an African hare species, Lepus crawshayi (de Winton, 1899). Both species are characterized by 2n = 48. While noticeable differences in the amounts of constitutive heterochromatin between the two taxa are apparent, the remarkable similarity of both chromosome morphology and G-banding pattern indicates a common evolutionary origin of the two genera. These observations support the hypothesis that the leporid ancestral karyotype has been maintained in the hares and certain of the rabbit taxa.

scholarly journals KARYOLOGICAL STUDY IN THE CHILEAN RHATANY Krameria cistoidea HOOK. & ARN. (KRAMERIACEAE)

2019 ◽  
Vol 30 (2) ◽  
pp. 21-25
Author(s):  
C. Palma Rojas ◽  
P. Jara Seguel ◽  
M. García ◽  
E. von Brand ◽  
C. Araya Jaime
Keyword(s):  
Banding Pattern ◽  
Relative Length ◽  
Chromosome Morphology ◽  
Chromosome Size ◽  
Banding Patterns ◽  
Karyological Study ◽  
C Banding ◽  
The Mean ◽  
Karyotype Morphology ◽  
Two Populations

The karyotype of the plant species Krameria cistoidea Hook. & Arn. was studied by assessing chromosome characters such as morphology, size, and C-banding pattern. The karyotype of K. cistoidea was composed only by metacentric chromosomes in the two populations studied. The haploid set length was 51.9±2.3 µm and the mean chromosome size was 8.68±0.78 µm. Some similarities in chromosome morphology and size can be observed among K. cistoidea and K. triandra, in addition to the chromosome number 2n=12 which is conserved within the genus. K. cistoidea exhibited a symmetric banding pattern with large C-bands in the telomeres of the short and long arms of all chromosomes, except the short arm of pair 1. The relative length of the C-bands was 23.5% of the total haploid set length. These cytological results on K. cistoidea are the first data on quantitative karyotype morphology and C-banding patterns in the genus Krameria. Key words: Krameria, karyotype, C-banding

On an Application of the Metallurgical Stage to Chromosome Morphology

1967 ◽  
Vol 25 ◽  
pp. 28-29
Author(s):  
Godfrey C. Hoskins
Keyword(s):  
Human Chromosome ◽  
Electron Micrographs ◽  
Chromosome Morphology ◽  
Electron Optics ◽  
Electron Micrograph ◽  
Photographic Evidence ◽  
Sophisticated Equipment ◽  
Periodic Arrangement

The first serious electron microscooic studies of chromosomes accompanied by pictures were by I. Elvers in 1941 and 1943. His prodigious study, from the manufacture of micronets to the development of procedures for interpreting electron micrographs has gone all but unnoticed. The application of todays sophisticated equipment confirms many of the findings he gleaned from interpretation of images distorted by the electron optics of that time. In his figure 18 he notes periodic arrangement of pepsin sensitive “prickles” now called secondary fibers. In his figure 66 precise regularity of arrangement of these fibers can be seen. In his figure 22 he reproduces Siegbahn's first stereoscopic electron micrograph of chromosomes.The two stereoscopic pairs of electron micrographs of a human chromosome presented here were taken with a metallurgical stage on a Phillips EM200. These views are interpreted as providing photographic evidence that primary fibers (1°F) about 1,200Å thick are surrounded by secondary fibers (2°F) arranged in regular intervals of about 2,800Å in this metanhase human chromosome. At the telomere the primary fibers bend back on themselves and entwine through the center of each of each chromatid. The secondary fibers are seen to continue to surround primary fibers at telomeres. Thus at telomeres, secondary fibers present a surface not unlike that of the side of the chromosome, and no more susceptible to the addition of broken elements from other chromosomes.

scholarly journals Impaired Expression of Cytoplasmic Actins Leads to Chromosomal Instability of MDA-MB-231 Basal-Like Mammary Gland Cancer Cell Line

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2151
Author(s):  
Vera Dugina ◽  
Galina Shagieva ◽  
Mariya Novikova ◽  
Svetlana Lavrushkina ◽  
Olga Sokova ◽  
...  
Keyword(s):  
Cell Line ◽  
Chromosomal Instability ◽  
Cell Transformation ◽  
Cancer Cell Line ◽  
Neoplastic Cell ◽  
Chromosome Morphology ◽  
Human Carcinoma ◽  
Actin Isoforms ◽  
Cytoplasmic Actin ◽  
Neoplastic Cell Transformation

We have shown previously that two cytoplasmic actin isoforms play different roles in neoplastic cell transformation. Namely, β-cytoplasmic actin acts as a tumor suppressor, whereas γ-cytoplasmic actin enhances malignant features of tumor cells. The distinct participation of each cytoplasmic actin in the cell cycle driving was also observed. The goal of this study was to describe the diverse roles of cytoplasmic actins in the progression of chromosomal instability of MDA-MB-231 basal-like human carcinoma cell line. We performed traditional methods of chromosome visualization, as well as 3D-IF microscopy and western blotting for CENP-A detection/quantification, to investigate chromosome morphology. Downregulation of cytoplasmic actin isoforms alters the phenotype and karyotype of MDA-MB-231 breast cancer cells. Moreover, β-actin depletion leads to the progression of chromosomal instability with endoreduplication and aneuploidy increase. On the contrary, γ-actin downregulation results not only in reduced percentage of mitotic carcinoma cells, but leads to chromosome stability, reduced polyploidy, and aneuploidy.

scholarly journals Chromosomal Analysis in Crotophaga ani (Aves, Cuculiformes) Reveals Extensive Genomic Reorganization and an Unusual Z-Autosome Robertsonian Translocation

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Rafael Kretschmer ◽  
Ricardo José Gunski ◽  
Analía del Valle Garnero ◽  
Thales Renato Ochotorena de Freitas ◽  
Gustavo Akira Toma ◽  
...  
Keyword(s):  
Robertsonian Translocation ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Rare Event ◽  
Chromosome Morphology ◽  
Z Chromosome ◽  
Molecular Cytogenetic ◽  
Intrachromosomal Rearrangements ◽  
Genomic Reorganization

Although cytogenetics studies in cuckoos (Aves, Cuculiformes) have demonstrated an interesting karyotype variation, such as variations in the chromosome morphology and diploid number, their chromosome organization and evolution, and relation with other birds are poorly understood. Hence, we combined conventional and molecular cytogenetic approaches to investigate chromosome homologies between chicken and the smooth-billed ani (Crotophaga ani). Our results demonstrate extensive chromosome reorganization in C. ani, with interchromosomal rearrangements involving macro and microchromosomes. Intrachromosomal rearrangements were observed in some macrochromosomes, including the Z chromosome. The most evolutionary notable finding was a Robertsonian translocation between the microchromosome 17 and the Z chromosome, a rare event in birds. Additionally, the simple short repeats (SSRs) tested here were preferentially accumulated in the microchromosomes and in the Z and W chromosomes, showing no relationship with the constitutive heterochromatin regions, except in the W chromosome. Taken together, our results suggest that the avian sex chromosome is more complex than previously postulated and revealed the role of microchromosomes in the avian sex chromosome evolution, especially cuckoos.

Thinopyrum distichum chromosome morphology and C-band distribution

1994 ◽  
Vol 88 (8) ◽  
pp. 949-955 ◽  
Author(s):  
G. M. Littlejohn ◽  
R. de V. Pienaar
Keyword(s):  
Chromosome Morphology
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