Amplification of telomeric DNA and the extent of karyotypic evolution.
The distribution of telomeric DNA in the genomes of the antelope ground squirrel, Ammospermophilus harrisii (family Sciuridae; 2n = 32) and the African black-footed cat, Felis nigripes (family Felidae; 2n = 38) were compared by fluorescence in situ hybridization (FISH) technique. These two mammalian species have the highest and the lowest amount of C-banded regions, respectively. FISH preparations with the human telomeric DNA probe showed that all C-banded segments in the A. harrisii chromosomes, except a few intercalary segments, were hybridizing with this DNA. F. nigripes showed hybridization only on the termini of each chromosome, and the C-banded regions did not hybridize with telomeric DNA on FISH analysis. The C-banded chromosomal arms in another rodent species, Peromyscus eremicus (family Cricetidae; 2n = 48), when hybridized with human telomeric DNA showed signals only in the termini of chromosomes but not in the heterochromatic arms. These observations indicate that not all C-banded regions in rodent species are telomeric DNA. The amplification of telomeric DNA in relation to speciation is discussed.
Pathak
S
S
Department of Cell Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
Dolhonde
J A
JA
Multani
A S
AS
D000818:Animals; D002503:Centromere / Q000737:chemistry; D002871:Chromosome Banding; D004247:DNA / Q000235:genetics*; D019143:Evolution, Molecular; D005784:Gene Amplification; D006570:Heterochromatin / Q000502:physiology*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008322:Mammals / Q000235:genetics*; D012377:Rodentia / Q000235:genetics; D013045:Species Specificity; D016615:Telomere / Q000737:chemistry*
D006570:Heterochromatin; D004247:DNA