The Genetic Code
The central dogma of life is DNA -> RNA -> Protein. One central key to this equation is the translation of RNA to Protein. This involves the decoding of 3 base pair RNA sequences into a single amino acid. These 3 base pair codes are called codons. There are 64 codons which encode 20 amino acids. Therefore, most of the amino acids are encoded by multiple codons. Codons that encode the same amino acid are referred to as synonymous codons. For a while it was believed that it didn't matter which synonymous codon you used. But now we know it does matter! There is an ever growing list of ways that synonymous codon usage can affect phenotypes and fitness. For examples see #3rdBaseThurs on Twitter.
Do you like beer, bread, cheese, wine, or kombucha? Well then you are a fan of the budding yeasts! These little cellular powerhouses have an incredible diversity in their evolutionary divergence, metabolic capability and lifestyle. While the budding yeast make us beer and wine there are also species that can cause human diseases. From the microbiome to the microbrewery, budding yeasts are everywhere! Additionally, we are working on sequencing 1000 budding yeast genomes. This makes them idea for studying the evolution of the genetic code.
Genetic Code in Budding Yeast
Remarkably the nuclear genetic code is exactly the same across all life on earth--except in the budding yeast! There are three major clades of yeast that have undergone a codon reassignment. In all other life the codon CUG is decoded as Leucine. In the budding yeasts there are species that can decode CUG as Serine or Leucine. With 1,000 budding yeast genomes on the horizon, this group presents the opportunity to study multiple areas of genetic code research including:
Evolution of codon reassignment
Causes and consequences of codon usage bias
Codon usage as a proxy for gene expression in reverse ecology