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The Evolution of Genome Size

T. Cavalier-Smith

出版	J. Wiley, 1985
主題	Science / Life Sciences / Cell BiologyScience / Life Sciences / Genetics & Genomics
ISBN	04711027259780471102724
URL	http://books.google.com.hk/books?id=YLETAQAAIAAJ&hl=&source=gbs_api

註釋

Genes consist of DNA, and their main function is to code for proteins. Therefore one might expect that the amount of DNA per cell would depend mainly on the number of different proteins an organism makes during its life: highly complex organisms with lots of different genes should have much more DNA than simple ones. But in eukaryotes measurements of the amount of DNA per haploid nucleus (an organism's 'genome size' or 'C-value') show no such simple pattern. The fact that some very simple unicellular organisms have huge amounts of DNA per genome, whereas some highly complex multicellular ones have many times less therefore poses a fundamental biological problem known as the 'C-value paradox'. Do the massive amounts of 'extra' DNA in organisms like some salamanders and lilies that have exceptionally large genomes have some function? If so what? Or is the extra DNA merely useless junk or a 'selfish' parasite ('selfish DNA') of the cells replication machinery?