Reference herein to an " endogenous" gene not only refers to the gene in question as found in an organism in its natural form (i.e., without there being any human intervention), but also refers to that same gene (or a substantially homologous nucleic acid/gene) in an
isolated form subsequently (re)introduced into a microorganism (a transgene). For example, a transgenic microorganism containing such a transgene may encounter a substantial reduction of the transgene expression and/or substantial reduction of expression of the endogenous gene. The isolated gene may be isolated from an organism or may be
manmade, for example by chemical synthesis.