Dispersed Repetitive DAN drDNA Fingerprinting, Nuclear Genomes, Eukaryotes Contain, Microsatellites, Minisatellites, Short Tendern Repeats

Home >> Biotechnology and Genomics >> DNA-Based Molecular Markers in Biotechnology >>Dispersed Repetitive DNA (drDNA) for DNA Fingerprinting

Your Ad Here	Dispersed repetitive DNA (drDNA). For DNA fingerprinting. Nuclear genomes of all eukaryotes contain repeats of short sequence motifs (2-15 bp in length), dispersed throughout the genome, which have been described either as dispersed repetitive DNA (drDNA), or as variable number of tandem repeats (VNTRs). These sequences mainly include minisatellites and microsatellites {the microsatellites have also been described as simple sequence repeats (SSRs) or short tandern repeats (STRs)} and can be detected, either through nucleic acid hybridization or through PCR amplification.
In the hybridization approach, cloned or synthetic oligonucleotides representing any of these short repeats are utilized as probes. Polymorphism in drDNA is resolved by RFLP technology, which is sometimes modified through the use of in-gel hybridization and, therefore, described as oligonucleotide in-gel hybridization/fingerprinting (in this in-gel technology, electrophoresed DNA fragments are not transferred to a filter as dome in Southern blotting for RFLPs, but instead the gels are dried and used directly for hybridization). These repeat sequences have been used as multi-locus probes, thus having the advantage of revealing polymorphisms at many loci simultaneously.
However, in some cases, as observed in tomato and bread wheat, they give only a few bands thus limiting their utility. Another disadvantage often attributed to the technique of in-gel hybridization is, that perhaps it does not allow detection of small segments representing unique sequences carrying these dispersed repeat sequences.	Your Ad Here