Question

40. Researchers can isolate a sample of cells, such as skin fibroblasts, and grow them in the laboratory. This procedure is called a cell culture (see Appendix A). A cell culture can be exposed to a sample of DNA. If the cells are treated with agents that make their membranes permeable to DNA, the cells may take up the DNA and incorporate the DNA into their chromosomes. This process is called transformation or transfection. Experimenters have transformed human skin fibroblasts with methylated DNA and then allowed the fibroblasts to divide for several cellular generations. The DNA in the daughter cells was then isolated, and the segment that corresponded to the transformed DNA was examined This DNA segment in the daughter cells was also found to be methylated. However, if the original skin fibroblasts were transformed with unmethylated DNA, the DNA found in the daughter cells was also unmethylated. Do fibroblasts undergo de novo methylation, maintenance methylation, or both? Explain your answer

Answer 1

These results indicate that the fibroblasts endure maintenance methylation as a result of they will replicate and methylate deoxyribonucleic acid if it's already been alkyl group. However, the cells don't endure First State novo methylation, as a result of if the donor deoxyribonucleic acid was unmethylated, the deoxyribonucleic acid within the female offspring cells remains unmethylated.