Study of genetic variation (genomics)

A student of microbiology

##What is genomics?##

The term genome was used to describe the complete set of chromosomes that made up a given species.The direct analysis of the genome of an organism, or the genomes of a group of organisms, is now possible through advances in the efficiency of DNA sequencing and large-scale genetic screening. These new high-throughput methods allow researchers to collect vast amounts of information about genetic variation in very short periods of time.

##How can we study human genetic variation?##

Humans can also be the focus of population genetics studies, as they too have been subject to the forces of change over long periods of time. Recently, the DNA sequence of the entire human genome was deciphered in a massive effort called The Human Genome Project (HGP).
** This project sequenced the DNA of each human chromosome from end to end, determined the DNA sequence of every human gene, and mapped the precise location of every human gene to a particular region of a human chromosome.With this information in hand, scientists now have a baseline definition of every human gene. With this baseline, they are beginning to study how the DNA sequences of human genes can vary among individuals and populations.**

In fact,scientists can currently study the variabilityof those genes (i.e. all allelic forms) in different populations around the globe. Early results from these studies indicate that humans are identical over the vast majority of their genome.
The apparently striking phenotypic variation among humanbeings around the world can be accountedfor by only an exceptionally small number of genetic differences. Genes that code forskin color, facial features, or body size represent a small fraction of the DNA that comprises the total human genome.

##How many genes does it take to build a human being?##

Although early reports suggested that human chromosomes might contain as many as 100,000 different genes, we now know that the 24 different human chromosomes altogether contain 20,000-25,000 different genes. However, it is likely that many of those genes are not absolutely required.

##Genomics and biological discovery##

Genomic data can support discovery in diverse areas of biology, including medicine, systematics, and conservation biology. Like many histories, the history of genomics is fraught with conflict, disagreement, and excitement. The personalities and ideas that have shaped genomics even included a race between publicly funded and corporate genome sequencing groups that resulted in a tie at the finish line.
Several subspecialty areas of genomics are also expanding as the community of scientists within them grows. These relatively new areas of genomic investigation include: epigenomics (the study of DNA modification), transcriptomics (the study of cellular RNA content), and proteomics (the study of proteins that characterize a particular cell).