ANIMALS Genomes of 51 animal species mapped in record time
Researchers just mapped and published the genomes of 51 animal species, from fish-eating crocodiles known as gharials to fierce cloud leopards. These genetic blueprints could have broad implications for humans, particularly for understanding our evolutionary history. “In some ways we’re building an evolutionary time machine,” said Michael Schatz, a Bloomberg distinguished professor of computer science and biology at Johns Hopkins University. “Having the genes of our evolutionary cousins mapped out will help us better understand ourselves.”
All mammals share a common ancestor, which many scientists believe to be Morganucodon, a tiny, shrew-like creature that lived more than 200 million years ago, though some say otherwise. In any case, this shared ancestor means that a large chunk of our genetic make-up resembles those of other mammals, particularly chimpanzees, which share up to 99 per cent of our DNA. By comparing the DNA of humans and other animals, researchers can learn when and how humans diverged from other species. But a single vertebrate genome can be billions of characters long, and researchers must use different tools to break this genetic material into chunks before piecing it into a full picture. As a result, mapping genomes has historically been a painstaking process. Beginning in 1990, it took researchers 13 years to create the first genetic blueprint for humans.
However, DNA mapping technology for different species has advanced rapidly in the past few decades, and this new project marks another step, cutting the sequencing time from years and months to just days. To achieve this, the team used research from two projects: the Vertebrate Genomes Project and the European Reference Genome Atlas. From these projects, they developed algorithms and computer software to assemble short genetic segments into a full genetic map, and eventually tested how well their workflow reproduced the complete genome of a zebra finch, which had been previously published.
The team found that their new technology was more effective than existing approaches at reassembling segments of the genome and creating an accurate map. Their software is open-source and available online via Galaxy, a free web-based platform based at Johns Hopkins and Pennsylvania State University. Researchers focused only on vertebrates; other animal, plant or fungal species might have “something distinctive or unique about their genome,” which means “some of the processes that are in this pipeline aren’t going to work as well in that species,” said Elinor Karlsson, director of the Vertebrate Genomics group at the Broad Institute. But this could be fixed “by modifying a few parameters” in their technique, according to the researchers. The goal is to sequence the genomes of at least one species across all 275 vertebrate orders.