Gene regulation Regulation of various stages of gene expression Main article: Regulation of gene expression The regulation of gene expression (or gene regulation) by environmental factors and during different stages of development can occur at each step of the process such as transcription , RNA splicing , translation , and post-translational modification of a protein. [86] The ability of gene transcription to be regulated allows for the conservation of energy as cells will only make proteins when needed. [86] Gene expression can be influenced by positive or negative regulation, depending on which of the two types of regulatory proteins called transcription factors bind to the DNA sequence close to or at a promoter. [86] A cluster of genes that share the same promoter is called an operon , found mainly in prokaryotes and some lower eukaryotes (e.g., Caenorhabditis elegans ). [86] [87] It was...