New applications of low-C0t DNA as a DNA fingerprint probe

Abstract

New applications of low‐C0t DNA are reported as probes for genetic identification and genome characterization. These fast and intermediately reannealing fractions have sometimes either been discarded in genomic library construction to enhance the probability of finding single copy genes, or they are used as resources for identifying individual repetitive sequences. In addition, they are used as blockers to enhance hybridization signals. C0t‐1 DNA serves as a probe for DNA fingerprinting of human yeast artificial chromosomes. We have isolated low‐C0t DNA from bacteria, fungus, plant, mussel, chicken, rat and fish from the sheared genomic DNA of the respective species. Low‐C0t DNA is labeled to generate DNA fingerprints and for in situ hybridization. Individual specific DNA fingerprint profiles are observed and species‐specific DNA fragments can be identified in bacteria, fungus, plants (Ginseng and Amaranthus) and mussel. When low‐C0t DNA probes from rat, chicken and fish were employed, only smear profiles and no distinct DNA banding patterns were evident. In these species, individual clones can be used as a probe for DNA fingerprinting containing repetitive sequences after subcloning. The advantage of this approach is to quickly develop a useful probe for DNA fingerprinting for genetic identification and analysis without sequencing knowledge a priori. This represents an innovative approach to the use of these repetitive components of the genome.

Isolation and characterization of sixty sequences of cot-1 DNA from the Asiatic black bear, Ursus thibetanus

“…Our results indicate the presence of polymorphic repetitive DNA families found when the genomic DNA was digested by HaeIII, a pattern may be detectable after subcloning, as discussed by Leung (Leung, 1999). There were also no distinct band patterns when Asiatic black bear cot-1 DNA was cross-hybridized with giant panda genomic DNA, demonstrating that the two species have no common dominant repetitive sequences ,except faint bands detected when the giant panda genome was digested by BamH I. Zheng 'an et al (1990) reported a tandemly repeated DNA which designated satellite 1 ,when the giant panda genome was digested by BamH I, suggesting that similar tandemly repeated DNA exists in the cot-1DNA from the Asiatic black bear.…”

Isolation and characterization of repetitive DNA sequences from Panax ginseng

“…The repetitive DNA sequences were obtained from the rapidly reassociating fraction of total P. ginseng genomic DNA using the low C o t method (Leung 1999). The term C o t refers to the product of initial DNA concentration (C o ) and incubation time (t, in s) (Gardner1981).…”