The thought of losing DNA for survival sounds bizarre, but many life forms do this at different stages of their life. For example, the parasitic worm Ascaris, also called the roundworm, loses about 13-90% of its germ cell DNA during their change to somatic cells, which are all of the other cells in the body.
Scientists now looked closer into what kind of DNA sequences are lost and where they go, using sequencing- and imaging-based techniques.
They found that all 24 chromosomes of Ascaris germ cells harbor DNA breaks close to the chromosome ends or telomeric regions. Although most of the DNA in and around the telomeres is lost, new telomeric DNA is attached back to somatic cells.
When they imaged the worm cells, they found broken DNA is densely packed inside of the nucleus by lipid membranes. This packed DNA was evicted out into the cytoplasm, where it was attacked by proteins deployed by the cells to eat waste cellular material (a process called autophagy).
At this moment, it is still not clear why Ascaris cells put in all this extra work to get rid of DNA. One prediction scientists propose is that Ascaris could get rid of DNA only necessary for germ cell function but not useful to somatic cells.