Your Learning Point

 Click On Any 1 Banner Given Below

To Unlock Download Link (Necessary)

Genomic analysis takes the approaches of genetic analysis and applies them to the collection of global data sets to fulfill goals such as the mapping and sequencing of whole genomes and the characterization of all transcripts and proteins. Genomic techniques require the rapid processing of large sets of experimental material, all dependent on extensive automation.

The key problem in compiling an accurate sequence of a genome is to take short sequence reads and relate them to one another by sequence identity to build up a consensus sequence of an entire genome. This can be done straightforwardly for prokaryotic genomes by aligning overlapping sequences from different sequence reads to compile the entire genome, because there are few or no DNA segments that are present in more than one copy in prokaryotes. 

The problem is that complex genomes are replete with such repetitive sequences. These repetitive sequences interfere with accurate sequence contig production. The problem is resolved by either whole genome shotgun (WGS) sequencing with the use of paired-end reads or clone-by-clone sequencing, which treats dispersed repetitive elements such as mobile elements as unique in the context of a clone. 

Un- like WGS sequencing, clone-by-clone sequencing re- quires that a physical map of the distribution of ordered and oriented clones be produced first so that appropriate clones forming a minimum tiling path through the genome can be selected for sequencing. Genomic sequence maps form the basis for making predictions of gene structure. 

Linkage and cytogenetic maps show the approximate locations of mutations with defined phenotypic effects. Locating polymorphic molecular markers on both the genetic and the sequence maps allows mutations to be localized to delimited regions of the genomic sequence maps. This method has greatly advanced progress in the positional cloning of genes of interest. 

Having a genomic sequence map provides the raw, encrypted text of the genome. The job of bioinformatics is to interpret this encrypted information. For the analysis of gene products, interpretation is accomplished by combining available experimental evidence for transcript structures (cDNA sequences), protein similarities, knowledge of characteristic sequence motifs, and comparative genomics.

Functional genomics attempts to understand the working of the genome as a whole system. A key approach is to determine the interactome, the set of inter- acting gene products and other molecules that together allow a living cell to be produced and to function.