Question

Which method is more truthful for DNA sequences?

 

 

 

Answer 1

Many researchers have proposed that ORF methods are very reliable and accurate in DNA Sequencing of prokaryotes, whereas in Eukaryotes BLAST method is found to be more useful.

ORF scans work well for bacterial genomes, they are less effective for locating genes in DNA sequences from higher eukaryotes. This is partly because there is substantially more space between the real genes in a eukaryotic genome (62% of the human genome is intergenic)increasing the chances of finding spurious ORFs. But the main problem with the human genome and the genomes of higher eukaryotes in general is that their genes are often split by introns, and so do not appear as continuous ORFs in the DNA sequence. Many exons are shorter than 100 codons, some fewer than 50 codons, and continuing the reading frame into an intron usually leads to a termination sequence that appears to close the ORF. In other words, the genes of a higher eukaryote do not appear in the genome sequence as long ORFs, and simple ORF scanning cannot locate them.