Integrons and Gene Cassettes in the Bacteria

Integron,a mobile DNA element that can capture and carry genes based upon which integrase gene they contain,particularly those responsible for antibiotic resistance.It is the simplest mobile DNA element ever know and contains two parts which are gene cassettes and a recombined site called 59-base element.It has been divided two class,Resistant Integron and Super Integron,based on integrase genes it contained and the difference of gene cassette’s function it captured.Gene cassettes are the mobile element which can be integrated into or cutted out from integron by the integrases.Gene cassettes always have two functional parts including a gene which inhabited the most sequences and a recombined site downstream the gene.Most of gene cassettes are antibiotics-resistant gene,and others are the function-unknown ORF.Integron and gene cassettes are possibly important in the capture of antibiotics-resistant and evolution of bacteria genome.