The below mentioned article provides a study note on genomics.

The complete genetic content of an organism is genome, and the DNA obtained is called genomic DNA. This genomic DNA of prokaryote contains all the coding region and can be sequenced, whereas the DNA of eukaryotes includes both intron and exon sequences (coding sequence) as well as noncoding regulatory sequences such as promo­ter, and enhancer sequences.

The subject genomics is the complete analysis of the entire genome of a chosen organism which involves the study of physical structure of the orga­nism’s genome or the genetic makeup of an organism to know the number of genes present and the type of genes, i.e., to study the function of different genes.

Whole Genome Sequence Data:

Complete nucleotide sequences of nuclear, mito­chondrial and chloroplast genomes have already been worked out in large number of prokaryotes and several eukaryotes. By the year 2005, among prokaryotes, approx. 1400 viral genomes, 250 bacterial genomes (230 eubacteria and 20 archaea), 500 mitochondr­ial genomes, 35 chloroplast genomes have been fully sequenced.

Among the eukaryotes namely the whole genome of Saccharomyces cerevisiae (yeast), Coenorhabditis elegans (nematode), fruitfly (Drosophila melanogaster), Human (Homo sapiens), Crucifer weed (Arabidopsis thaliana) and rice (Oryza sativa) have been sequenced already and data available for annotation studies.

The sequence data of eukaryotic nuclear genome is an important source of identi­fication, discovery and isolation of important genes. This data is very much helpful in variety of application relevant to animal, plant and microbial biotechnology.

Functional and Structural Genomics:

Once the whole genome sequence becomes available, the next step is to assign the function to different regions of genome. Functional genomics is the subject which is based on the use of genetic information to delineate protein structure, function, pathways and networks.

Function may be determined by ‘knocking out’ and ‘knocking in’ expressed genes in model organisms such as worm, fruitfly, yeast or mouse. Structural genomics involves solving the experimental structures of all possible pro­tein folds which is playing an important role in high throughput function assignment.

Significance of Genomics:

All the information’s require input in probability theory, database management arid manipulation, and computer science.

This will help in:

(a) Identification of open reading frame sequences,

(b) Gene splicing sites (introns),

(c) Gene annotation (inter-genomic comparisons) and

(d) Determination of sequence pat­terns of regulatory sites and gene regulations.

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