Metagenomics: DNA sequencing of environmental samples

DNA sequencing can provide insights into organisms that are difficult to study because they are inaccessible by conventional methods such as laboratory culture.Isolation and sequencing of DNA from mixed communities of organisms (metagenomics) has revealed surprising insights into diversity and evolution.Genomic DNA sequence, and even complete genomes in some cases, has been generated from organisms that exist only in tight association with other organisms, including various obligate symbionts and pathogens, members of natural microbial consortia and an extinct cave bear.Partially assembled or unassembled genomic sequence from complex microbial communities has revealed the existence of novel and environment-specific genes.Advances in DNA sequencing technology and computational methods promise to accelerate progress in metagenomics.