 Common research topics in model organism genetics include the study of gene regulation and the involvement of genes in development and cancer.Organisms were chosen, in part, for convenience—short generation times and easy genetic manipulation made some organisms popular genetics research tools.Widely used model organisms include the gut bacterium "Escherichia coli", the plant "Arabidopsis thaliana", baker's yeast ("Saccharomyces cerevisiae"), the nematode "Caenorhabditis elegans", the common fruit fly ("Drosophila melanogaster"), and the common house mouse ("Mus musculus").