On Estimating Functional Gene Number in Eukaryotes
Nature New Biology
MANY recent studies have been concerned with the construction of biological model systems to describe adequately regulation of gene action during development of eukaryotes1–5. The number of genes in mammals and Drosophila has been suggested to be 1 to 2 orders of magnitude less than the amount of available DNA per haploid genome could provide2–7. Although Drosophila and mammalian nuclei contain enough unique DNA to specify for respectively 105 and 106 genes of 1,000 nucleotide pairs8,9, it has been argued that a much lower estimate of functional gene number is more reasonable2–7. Conversely, these conclusions indicate that more than 90% of the eukaryotic genome may be composed of nonfunctional or noninformational “junk” DNA. Here we demonstrate these estimations have not been fundamentally proven; rather they are based on simplifying assumptions of questionable validity, in some cases contradictory to experimental data.
O'Brien, Stephen J.. 1973. "On Estimating Functional Gene Number in Eukaryotes." Nature New Biology 242, (115): 52-54. doi:10.1038/newbio242052a0.