Genome, Genome

The term genome can be applied specifically to mean that stored on a complete set of nuclear DNA (i.e., the "nuclear genome") but can also be applied to that stored within organelles that contain their own DNA, as with the mitochondrial genome or the chloroplast genome. Additionally, the genome can comprise nonchromosomal genetic elements such as viruses, plasmids, and transposable elements . When people say that the genome of a sexually reproducing species has been "sequenced", typically they are referring to a determination of the sequences of one set of autosomes and one of each type of sex chromosome, which together represent both of the possible sexes. Even in species that exist in only one sex, what is described as "a genome sequence" may be a composite read from the chromosomes of various individuals. In general use, the phrase "genetic makeup" is sometimes used conversationally to mean the genome of a particular individual or organism.

At present, the highest known number of genes is around 60,000, for the protozoan causing trichomoniasis (see List of sequenced eukaryotic genomes), almost three times as many as in the human genome.

In such circumstances then, "genome" describes all of the genes and information on non-coding DNA that have the potential to be present.

Cheetahs vary, and so do the sequences of their genomes. Yet both the individual animals and their sequences share commonalities, so one can learn something about cheetahs and "cheetah-ness" from a single example of either.

Other genome projects include mouse, rice, the plant Arabidopsis thaliana , the puffer fish, bacteria like E. coli, etc.

The first DNA-genome project to be completed was the Phage -X174, with only 5368 base pairs, which was sequenced by Fred Sanger in 1977.

Among many genome database sites, the one maintained by the US National Institutes of Health is inclusive. http://www.ncbi.nlm.nih.gov/sites/entrez?db=Genome&itool=toolbar These new technologies open up the prospect of personal genome sequencing as an important diagnostic tool.

There is experimental work being done on minimal genomes for single cell organisms as well as minimal genomes for multicellular organisms (see Developmental biology). The work is both in vivo and in silico.

Source: Wikipedia > Genome