Complex sentence: There are many modes by which this alteration of gene expression can occur, including methylation of DNA and histone modification; however, the important point is that both inheritance of random mutations and epigenetic markers can result in the expression of antibiotic resistance genes.
Split into simpler sentences: There are many modes by which this alteration of gene expression can occur. This includes methylation of DNA and histone modification; however, the important idea is that both inheritance of random mutations and epigenetic markers can result in the expression of antibiotic resistance genes.