The Remains of a mammoth Stepario of 1.1 million years allowed to rebuild partial genomes of a pathogenwhich represents the microbial DNA associated with an older host.
The analyzes carried out by a team of researchers headed by the University of Stockholm also allowed several microbes to be found in mammoth remains that “were probably associated with pathogenic processes” in those animals.
This was explained to Efe the researcher David Díez del Molino, of the Paleogenetic Center of the University of Stockholm and one of the signers of the study in which the Spanish paleontologist Juan Luis Arsuaga participated, among others.
The article published by Cell analyzed the presence of microbes associated with the remains of 483 mammoth specimens throughout the evolution of the species, of which 440 had not been previously studied.
The team used advanced genomics and bioinformatics techniques to distinguish microbes who lived next to the mammoths of those who invaded their remains after their death.
The results “open,” said Díez, “the possibility of analyzing and understanding the relationship of extinct species with microbes and pathogens that could influence both their evolution and the extinction process.”
The genomes of microbes evolve rapidly, so “obtaining reliable DNA data of more than one million years was like following a trace that constantly rewritten,” he explained in a statement Tom Van der Walk, from the University of Stockholm and also a signatory of the study.
When DNA is older, it is more complicated to find nearby microbes present genomes present today, but the team was able to identify six “potentially related to an animal host,” said Diez.
They were placed in the phylogenetic tree with their current relatives and verified if they were associated with similar ones that are known pathogens today.
Among the six constantly associated microbial groups with host mammoths were Actinobacillus, Pasteurella, Streptococcus and Erysipelothrix relatives.
A bacterium related to Pasteurella, identified in the study, is closely related to a pathogen that has caused mortal outbreaks in African elephants.
Since African and Asian elephants are the closest living relatives of mammoths, these findings raise the question of whether mammoths could also have been vulnerable to similar infections.
The team rebuilt partial genomes of the Erysipelothrix bacteria from An steparium mammoth of 1.1 million years old, which represents the microbial DNA associated with an older host.
(EFE Agency)
Although it is difficult to determine the exact impact of the microbes identified in the health of mammoths due to the degradation of the DNA and the limited comparative data, the study offers an unprecedented vision of the microbiomes of the extinct megafauna.
The results suggest that some microbial lineages coexisted with these animals for hundreds of thousands of years, covering large geographical areas and evolutionary temporal scales, for more than one million years until the extinction of the Lady mammoths on the island of Wrangel about 4,000 years ago.
Ancient remains can keep biological information that goes far beyond the host genome, offering perspectives on how microbes influenced the adaptation, diseases and extinction in the ecosystems of the Pleistocene, said Van der Valk.
Until now, this type of studies were basically focused on ancient humans. In that case, the oldest cases of DNA of bacteria found would be two of Corynebacterium diphtheriae (cause of diphtheria) dated from 11,000 years ago, said Díez.