Meet the butterfly with the most chromosomes in the World – Here’s its incredible story

Image of the Atlas blue butterfly, captured by Roger Vila, senior author of the study. (Image: Dr Roger Vila / The Institute of Evolutionary Biology)

Scientists have uncovered a remarkable secret about butterflies. The Atlas blue butterfly carries more chromosomes than any other. Researchers at the Wellcome Sanger Institute and Barcelona’s IBE confirmed this discovery.

What Makes the Atlas Blue Butterfly Unique?

The Atlas blue butterfly, scientifically named Polyommatus atlantica, has 229 chromosome pairs. Most related butterflies carry only 23 or 24 pairs. Scientists sequenced the butterfly’s genome for the first time. Their study was published in Current Biology on 10 September. This research produced a gold-standard reference genome. Experts can now compare its DNA with other species.

Instead of duplicating chromosomes, the butterfly’s chromosomes split over time. Scientists found splits occurred where DNA was less tightly wound. All chromosomes, except sex chromosomes, are divided into smaller sections. This increased the number from 24 to 229 in about three million years. Evolution usually works much slower.

Why Is This Discovery Important for Science?

Could these chromosome splits help the butterfly adapt faster? Researchers suggest greater genetic shuffling might improve diversity. This may explain why the species survived millions of years. Climate change and human activities now threaten its survival. Deforestation and overgrazing harm its habitat in Morocco and Algeria.

Experts believe studying the butterfly’s DNA could help cancer research. Chromosomal rearrangements also appear in human cancer cells. Understanding this butterfly process could reveal ways to prevent cancer changes.

Dr Roger Vila of IBE explained why this matters. He said splitting chromosomes could affect butterfly behaviour. Dr Charlotte Wright from the Sanger Institute added this research helps conservation. It reveals how species adapt and survive changing climates.

Professor Mark Blaxter from the Sanger Institute highlighted genome importance. He said understanding species’ evolution helps predict their future. He also said comparisons may inform solutions for cancer research.

The Atlas blue butterfly is a rare creature in danger. Now, thanks to this research, its genetic story is known. Researchers hope this information keeps biodiversity and human health safe.