How Does DNA Move?
DNA movement isn't a singular process but depends heavily on the context. It moves in different ways depending on the cellular process involved.
Cell division is the primary mechanism for DNA transfer between generations. As stated in the provided reference, "Cell division is the mechanism by which DNA is passed from one generation of cells to the next and ultimately, from parent organisms to their offspring." This process involves:
- Mitosis: In eukaryotes, mitosis duplicates and separates the DNA, ensuring each daughter cell receives a complete copy. (Nature Scitable)
- Meiosis: In eukaryotes undergoing sexual reproduction, meiosis reduces the chromosome number by half, creating gametes (sperm and egg cells) with a unique DNA combination. (Nature Scitable)
- Binary Fission: Prokaryotes (bacteria and archaea) replicate their DNA and divide via binary fission.
DNA Movement During Transcription and Replication
- RNA Polymerase Movement: During transcription, RNA polymerase moves along the DNA template strand, unwinding it to synthesize messenger RNA (mRNA). The movement isn't a simple linear progression; it's "jerky," pausing at certain sequences. (NCBI Bookshelf, Biology Stack Exchange)
- DNA Replication: DNA replication involves the unwinding of the DNA double helix and the synthesis of new complementary strands by DNA polymerase. One strand is synthesized continuously (leading strand), while the other is synthesized in fragments (lagging strand). (NCBI Bookshelf)
DNA Movement in Gel Electrophoresis
Gel electrophoresis is a laboratory technique that separates DNA fragments based on size. Smaller DNA fragments move faster through the gel matrix than larger fragments due to their reduced frictional resistance. (YourGenome, NCBI PMC, NCBI PubMed, ResearchGate, UNL) The movement is influenced by factors such as the gel concentration, DNA conformation (supercoiled DNA migrates differently than linear DNA), and the applied electric field.
Transposons: "Jumping Genes"
Some DNA sequences, called transposons or "jumping genes," can move around within a genome. Their movement is mediated by enzymes that cut and paste, or copy and paste, the DNA sequence to a new location. (Nature Scitable)
