At the glance there is not much special about the blue that flies around in the high mountains of the Atlas, from Algeria to Morocco. But there is a surprise in the cells of the butterfly. The DNA in every cell nucleus of the Atlasturkooisblauwtje (Polyommatus Atlantica) includes no fewer than 229 pairs of chromosomes, a rare record in the animal kingdom. It is also almost ten times as much as the chromosome number of a next to family member, the icarus blue, which has 23 chromosoopers.
Some plant species have even more chromosomes than the Atlasturoois blue, but that can always be traced to a doubling of existing chromosomes. The special thing is that the high number of this butterfly was created by the breaking of its chromosomes.
What happened here British geneticists wondered. They took the trouble to map the whole genome of the butterfly.
They hoped that the research could also teach them something about the genetics of cancer. Chromosomes also often get fragmented in tumor cells, they write. But despite their in -depth genetic knowledge, they have not been able to find out, so that the genetic material of the atlasturkoois blue is cut into small pieces. What struck them is that all those minichromosomas have about the same length of 2,000 base pairs. Would that be the biological minimum for a viable chromosome length?