Biology

Same genome, different programs

Every cell in your body carries the identical genome; a neuron and a skin cell do totally different jobs only because each switches on a different subset of those same genes. Forensic labs exploit exactly this: the FBI's CODIS database has matched DNA from blood, hair, and skin to one person since 1998.

Sources & further reading

NCBI Bookshelf, National Library of Medicine (NIH) / Garland ScienceThe Molecular Genetic Mechanisms That Create Specialized Cell TypesA standard cell-biology textbook chapter explaining that cell types differ by which genes are switched on, not by different DNA.NCBI Bookshelf, National Library of Medicine (NIH) / Sinauer AssociatesDifferential Gene ExpressionA developmental-biology textbook chapter on how one genome produces hundreds of distinct cell types.National Human Genome Research Institute (NHGRI), NIHInternational Human Genome Sequencing Consortium Describes Finished Human Genome SequenceThe U.S. government's genome institute reporting how many protein-coding genes are in the finished human genome.Nature (via PubMed, NIH)Viable offspring derived from fetal and adult mammalian cellsThe Dolly-the-sheep paper proving an adult cell's nucleus still holds a whole organism's worth of instructions.Cell (via PubMed, NIH)Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined FactorsThe paper showing scientists can flip an adult cell's gene-expression pattern back to a blank-slate stem cell using just four switches.Federal Bureau of Investigation (FBI)CODIS and NDIS Fact SheetThe FBI's own fact sheet on the national DNA database that matches profiles regardless of which tissue a sample came from.Japan Agency for Medical Research and Development (AMED)First-in-human iPSC retinal cell transplant follow-upA Japanese government research agency's report on the first transplant of a patient's own reprogrammed skin cells into their eye.PubMed Central (PMC), National Library of Medicine (NIH)Azacitidine as an epigenetic therapy for myelodysplastic syndromesA research review explaining how an approved bone marrow drug reopens silenced genes without changing a patient's DNA sequence.The Nobel Prize (Nobel Foundation)The Nobel Prize in Physiology or Medicine 2012The Nobel Foundation's own record of the prize awarded for proving an adult cell can be reset back to a stem cell.