Some have argued that this analogy becomes questionable once we move from the genetics of simple prokaryotic organisms (bacteria and archaea), to those in eukaryotic cells (Sarkar 1996). Mainstream biology tends to regard the complications that arise in the case of eukaryotes as mere details that do not compromise the basic picture we have of how gene expression works (for an extensive discussion of these complexities, by those who think they really matter, see (Griffiths and Stotz 2013)). An example is the editing and “splicing” of mRNA transcripts. The initial stage in gene expression is the use of DNA in a template process to construct an intermediate molecule, mRNA or “messenger RNA”, that is then used as a template in the manufacture of a protein. The protein is made by stringing a number of amino acid molecules together. In eukaryotes the mRNA is often extensively modified (“edited”) prior to its use. Moreover, much of the DNA in a eukaryotic organism is not transcribed and translated at all. Some of this “non-coding” DNA (note the informational language again) is certainly functional, serving as binding sites for proteins that bind to the DNA thus regulating the timing and rate of transcription. The extent of wholly nonfunctional DNA remains unclear. These facts make eukaryotic DNA a much less straightforward predictor of the protein’s amino acid sequence than it is in bacteria, but it can be argued that this does not much affect the crucial features of gene expression mechanisms that motivate the introduction of a symbolic or semantic mode of description.