Image copyright EPA Image caption Analysis of new DNA sequences of Han races from the Chinese plains reveals the Omicron variant
An additional new version of DNA containing an extended sequence in a DNA base from a polar bear has been discovered in a Chinese region where fossils of the animal are also found.
It indicates the existence of the species long thought to have gone extinct.
This particular gene is associated with a rare collection of rare Han races in the shallow beds of Chinese plains.
Analysis of DNA samples from nine Han races has revealed that the DNA is unique.
Data from a number of others across China also show evidence of the Omicron variant.
Researchers say this “single copy” represents a new species because almost all of the other Chinese Han races share a common ancestor.
As a result, the Han races of Omicron pack the largest animal-genome-genes family known.
Image copyright EPA Image caption The study is published in the online journal PLOS Biology.
Every animal group contains genomic elements that are identical in nearly every other member.
Theoretically, new gene sequences from all these organisms could be found in the genomes of various groups.
However, it would be practically impossible to search the genomes of most species, because the number of family genes shared by all the members of most groups is too small.
The team of researchers, led by the Oxford University’s Bruce Cuthbert, thought they might be able to find DNA sequences hidden in Han races in China by analysing DNA from endangered species.
Instead, they came up with the Omicron variant, which was a particular surprise.
“In the field of modern genetics we often find new gene combinations when applying a generic technique like Next Generation Sequencing (NGS) to DNA sequences from fossils,” said Professor Cuthbert.
“But we don’t often find things that have never been discovered before.”
The team were amazed to find that the new DNA had already been sequenced and published in two papers in PLOS Biology.
Image copyright EPA Image caption Several Han races from southern China also share this gene
“The fact that we were able to find this complex genome sequence in the repository of fragments we had been pulling out of fossilised DNA tells us something different about how and why the Han race genes can be found in all these new Han races,” said Rosie Hemming, a co-author of the paper.
Previous genetics research had suggested the Omicron variant was formed from two distinct variants.
In response to this study, an expert in mammalian genomics at Oxford University welcomed the discovery of Omicron.
“In the present context, this paper… is a game changer: a major addition to our knowledge of the HLA-DRM lineage,” said Professor Sir Peter Voigt.
The information gained from the genetic analysis will be used to help scientists understand how gene variants are passed on from mother to child.