Scientists Discover New Type of Extra-Chromosomal DNA

eccDNA
Profile of eccDNA throughout the life cycle of Drosophila. 2D-gel blots of DNA samples from different stages of the Drosophila life cycle were hybridized with a total genomic DNA probe (A—F) or a 5S rDNA probe (G—J). The panels represent 2D-gel blots of (A,I) pre-MBT embryos, (B,H) late embryos, (C,I) first-instar larvae, (D,J) third-instar larvae, (E) young adult flies (1 day old), and (F) old adult flies (33 days old). The hybridization patterns reveal a decrease in the relative amount of eccDNA during embryogenesis (cf. panels A,B and panels G,H), and a gradual return to the initial levels in the larva and young adult stages. A slight decrease is observed in eccDNA levels in old adult flies compared with young adult flies. Image: genome.cshlp.org

Scientists from the University of Virginia and University of North Carolina have discovered a previously unidentified type of circular DNA molecule occurring outside the chromosomes in mouse and human cells. The findings were published in the journal Science.

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