The idea of bringing extinct animals back to life has captured the imagination of the public, but what should scientists focus on first?
The Christmas Island rat, which died out around 120 years ago, could be brought back to life using gene editing.
Their paper, published in Current Biology on Wednesday, demonstrates how close scientists could get using current technology, even though they did not follow through and create a living specimen.
Tom Gilbert, an evolutionary geneticist at the University of Copenhagen, told Agence France-Presse that he was not doing de-extinction, but that it was a really interesting idea.
There are three pathways to bring back extinct animals: back-breeding related species to achieve lost traits, cloning, and genetic editing, which Gilbert and colleagues looked at.
The idea is to take surviving DNA of an extinct species, and compare it to the genome of a closely related modern species, then use techniques like CRISPR to edit the modern species's genome in the places where it differs.
The edited cells could be used to create an embryo.
The genome of a modern species is like a reference book that can be used to piece together the fragments of its degraded counterpart, according to Gilbert.
His interest in Christmas Island rats was stimulated by a colleague's study of their skins.
It is thought that black rats brought on European ships wiped out the native species.
Key functions have been lost.
The team was able to reconstruct 95 percent of the Christmas Island rat genome using brown rats as their reference species.
That may sound like a big success, but five percent of the rat was not recovered because it was from regions of the genome that controlled immunity and smell.
Even if we have the perfect ancient DNA situation, we still have a long way to go, even if we have a really good sample.
The two species were close in evolutionary time, but not close enough to fully reconstruct the lost species.
This has important implications for de-extinction efforts, such as a project by Colossal to resurrect the mammoth, which died out around 4,000 years ago.
The evolutionary distance between elephants and mammoths is the same as that between brown rats and Christmas Island rats.
The last surviving member of the Tasmanian tiger died in captivity in 1936.
The replica animals created with the technique would have certain critical deficiencies.
He said it doesn't really matter if you bring back a mammoth to raise money or awareness.
If the goal is to bring the animal back in its original form, that will never happen, he said.
Gilbert admitted that he had mixed feelings about de-extinction projects.
He said he would put his money into protection if he had to choose between protecting what was left or bringing back something.
More information: Jianqing Lin, Probing the genomic limits of de-extinction in the Christmas island rat, Current Biology (2022). DOI: 10.1016/j.cub.2022.02.027. www.cell.com/current-biology/f … 0960-9822(22)00249-4 Journal information: Current BiologyThere will be a new year in 2022.
Citation: Forget mammoths, study shows how to resurrect Christmas Island rats (2022, March 13) retrieved 14 March 2022 from https://phys.org/news/2022-03-mammoths-resurrect-christmas-island-rats.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
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