Researchers breakthrough sequencing genome of ancient horse
Prof Eske Willerslev has said the successful sequencing of a horse genome has broadened the frontier for the theory of evolution, which has key prospects for domesticating genetic materials.
He said this scientific breakthrough and approaches could give more impetus and deepen the understanding of the theory of early human evolution in particular and those of animals in general.
Prof Willerslev, speaking to the Ghana News Agency on the sidelines of the World Conference of Science Journalists in Helsinki, Finland on a study into an “Ancient horse gerome sequencing” said the results are encouraging and a pointer in the right direction.
The study published online in ‘Nature’, an international weekly journal of science on Wednesday is a low-coverage draft genome sequence from a horse bone recovered from permafrost dating to around 700,000 years ago. These data represent the oldest full genome sequence to date by about half a million years.
Two research groups co-authored by Prof Willerslev and Dr Ludovic Orlando, both of the Centre for Geo-Genetics, Natural History Museum of Denmark, University of Copenhagen, Denmark, recovered a fossil horse bone, which dates back from 560 -780 thousand years ago, from permafrost in Yukon territory, Canada.
They sequenced the genome and compared it to another ancient horse, from the around 43,000 years ago, as well as five contemporary horse breeds, a Przewalski’s horse and a donkey.
Comparative genomics analyses suggest that the Equus lineage that gave rise to all contemporary horses, donkeys and zebras originated around four million years ago, twice the conventionally accepted time.
The authors find that the horse populations have fluctuated multiple times over the past two million years, particularly during times of severe climatic change, and that there is evidence for continuous selection on the immune system and olfaction throughout horse evolution.
The data also support the contention that Przewalski’s horses represent the last surviving wild horse population and reveal genomic regions that were probably selected during domestication.
The study suggests that a significant fraction of short Deoxyribonucleic Acid (DNA) fragments may survive for over a million years in the geosphere.
Methods for maximizing the retrieval of short but still informative, DNA, combined with whole-genome enrichment approaches, may unlock genomic clues about specimens previously thought to be much too old to sequence.
Prof Willerslev said the team was collecting bones of horses from all over the world for sequencing to enable them complete studies in the natural evolution of horses and what processes have evolved and attempt to modify them.
Source: GNA