Team II Gene Prediction Group
Introduction
Gene Prediction
Data
Approaches
1. Ab-initio
2. Comparative
Ab-initio Approaches
Comparative Approaches
Comparative, similarity based or Homology based gene prediction uses previously sequenced genes and their protein products as a template for recognition of unknown genes in a newly sequenced DNA fragments. So, in short we cab say: It is using "Known Genes" to predict "New Genes".
Figure 2: Given a known gene and an unannotated genome sequence, find a set of substrings in the genomic sequence whose concatenation best matches the known gene
Recently, the number of sequenced genomes has increased drastically and 99% of genes have homologous partner, 80% have orthologous partner and 85 % identity (protein coding DNA) versus 69 % identity (intronic DNA). All these can be considered as the motivation of using this method of gene prediction.