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Genome Tool Developed at CAS Featured in PLoS Genetics

29. 05. 2025

The latest issue of PLoS Genetics features a striking butterfly on its cover and a scientific article that delves deep into the evolutionary processes shaping species. One of two senior authors of the study is Stuart J. E. Baird from the Institute of Vertebrate Biology, Czech Academy of Sciences, who contributed not only his expertise but also a powerful admixture genomics tool: diem (Diagnostic Index Expectation Maximisation).

In the study by Ebdon et al., researchers examine a narrow contact zone between two closely related butterfly species—Iphiclides podalirius and Iphiclides feisthamelii—north of the Pyrenees. I. podalirius can already be seen gliding around the Czech Republic at this time of year, while I. feisthamelii is found in Iberia and north Africa. Despite diverging over a million years ago, these two species still hybridize. The team used chromosome level whole-genome sequencing to track how gene flow varies across different regions of the genome and over different timescales.

A key part of the analysis was enabled by diem, a method developed by Baird and Natália Martínková (also from IVB CAS), which rapidly identifies genome regions that resist or permit gene flow. This allows scientists to detect the genomic architecture of reproductive isolation—critical to understanding speciation.

“Diem lets us polarize genomes, revealing where barriers to gene flow and regions of admixture,” says Baird. “It’s like having a new kind of microscope for speciation genomics.”

The method was introduced in Methods in Ecology and Evolution and is now gaining international recognition for its speed, accuracy, and wide applicability. Diem can be used across fields ranging from evolutionary biology to archaeology. Potential work includes detecting traces of Neanderthal DNA in modern humans or adaptive gene flow between wild and domestic species.

After more than 15 years of development, diem has become a game-changing tool in admixture genomics—now helping unlock the secrets of speciation in butterflies.

Original article:
https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1011655

 

 

The Czech Academy of Sciences (the CAS)

The mission of the CAS

The primary mission of the CAS is to conduct research in a broad spectrum of natural, technical and social sciences as well as humanities. This research aims to advance progress of scientific knowledge at the international level, considering, however, the specific needs of the Czech society and the national culture.

President of the CAS

Prof. Eva Zažímalová has started her second term of office in May 2021. She is a respected scientist, and a Professor of Plant Anatomy and Physiology.

She is also a part of GCSA of the EU.