On the trail of the woolly mammoth

This tusk is located under the midnight sun in Siberia, from a mammoth – an Ice Age proboscis. A new study shows what genetically distinguishes these animals from their current relatives.

Only since Jurassic Park have scientists thought about the possibility of bringing extinct species back to life. According to the currently most discussed method, it could work if certain key genes from animals that are no longer present in a relative’s genome today are introduced. “Modifying the genome of a living species to mimic an extinct relative is generally not easy. The new findings highlight the complexity and difficulties that lie ahead,” says Loew Dallen from the Center for Paleogenetics in Stockholm.

The mammoth tusk shown in this image has now helped expand knowledge about the genetic makeup of one of these extinct animal species – the woolly mammoth. Canine tusks were discovered in northeastern Siberia and preserved in permafrost for thousands of years still containing intact DNA. Together with an international team of researchers, Dalin sequenced the genome of this other Siberian mammoth from the last Ice Age and compared it to the genomes of 33 previously published mammoths and the genomes of Asian and African elephants. The focus was on the parts of the gene that no longer exist, the so-called gene deletions, and on short insertions, the inserts that can lead to mutations and make the sequence unreadable.

Scientists have found that there are several thousand deletions and insertions throughout the woolly mammoth genome, affecting more than three million letters in the genetic code. Most of these mutations occurred outside the genetic blueprints of the proteins. “However, we also found 84 genes affected by genetic deletion and three genes affected by short insertion,” says Tom van der Valk, Dallen’s fellow and co-author. “It is likely that these structural changes have a significant impact on the function of these genes and may have contributed to some of the unique adaptations of the woolly mammoth.”

So changes in these 87 genes could be crucial to the survival of the far northern animals. Several of these affected genes are linked to classic woolly mammoth traits. These include, for example, fur, hair shape, fat deposits, body shape and ears,” explains co-author Marianne DeHasek. In order to induce these characteristics in relatives today, scientists will have to cut out entire parts of the genome and insert three genes.

© wissenschaft.de – Jan Fleischer