Final answer:
To determine the function of a gene in a bacterium, knockout mutation techniques within reverse genetics can be used by observing phenotypic changes resulting from gene deletions or mutations. Reporter genes such as lacZ and GFP can also be used to monitor gene expression and deduce function.
Step-by-step explanation:
To determine the function of a particular gene in a common bacterium with a haploid genome, one effective method that can be used is a knockout mutation. This technique falls under the umbrella of reverse genetics, where researchers start with a known gene and use mutations or deletions to observe the resulting phenotypic changes.
If we 'knock out' a gene and the bacterium loses a specific function or exhibits a new phenotype, we can infer that the disrupted gene was responsible for that trait or function. Additionally, methods like gene targeting can be utilized, which involves either introducing mutations in a gene or deleting part or all of the gene's sequence to study its role.
Another approach in reverse genetics is using reporter genes, such as lacZ and the green fluorescent protein (GFP), to track expression and determine the function and location of the gene of interest within the bacterium. Specifically, lacZ encodes the enzyme beta-galactosidase, which can cause a color change in the presence of the substrate X-gal. GFP can be monitored under UV light, as it glows green, indicating where and when the gene is being expressed.