Metagenomic analysis of frozen reindeer droppings provides an estimate for when a ninth reindeer joined the sleigh-ride, the genetics associated with a glowing red nose, and the fungal diet of apparently ageless reindeer.
Scientists in Norwich had been investigating extreme microbes in a variety of environments, including Iceland’s volcanic, glacial landscape, when they came across a quite staggering find.
Amid the thawing ice of a blue glacier cave near to the sampling site, the frozen remnants of droppings long-since dropped were revealed, which were immediately recognised as those belonging to reindeer.
The droppings were found in a location not dissimilar to this blue ice cave.
Bizarrely, however, although reindeer do indeed exist in Iceland - with around 7000 individuals roaming the country - they are mostly restricted to the east of the main island. This mound of thawing reindeer excrement was found on the South of the island, prompting an interested flurry of activity amidst the slurry.
Digging deeper into the ice underneath the samples, year upon year of faeces was unearthed, revealing layer upon layer of reindeer droppings which appeared unfalteringly at the same spot.
Analysing the faecal material akin to measuring Antarctic cores, the team set aside their metagenomic analysis of extremophile microbes and proceeded to analyse the mystery droppings laid abundantly before them, revealing an interesting history.
Sleigh bells ring
The reindeer droppings were dated back to the early 15th century by analysing the different layering patterns in the ice around the site and DNA was extracted from samples in each of the layers, the deepest of which had been frozen solid since the times of Henry VIII.
Due to the preservative nature of the deep freeze, the samples yielded a remarkable amount of DNA.
Comparison with the recently published reindeer genome showed that, in the early 15th Century, ten individual reindeer were represented amongst the frozen droppings. Remarkably, though two of these individuals disappeared within the first eight years of samples, eight of the original individuals have persisted to this day.
Even more excitingly, an additional reindeer was detected in the samples, appearing around 1935.
Simply finding evidence for eight, apparently ageless, reindeer was exciting enough. Yet, this date for an emergence of novel reindeer DNA in the samples seems to correspond to about the time of the first appearance of “Rudolph the red-nosed reindeer” in modern cultural awareness.
This really set the sleigh bells ringing for the team, who had, until now, refused to believe that this could possibly be the find that the results initially suggested.
Armed with an Oxford Nanopore MinION and the latest in bioinformatics tools, such as NanoOK RT, the team was quick to perform real-time analysis of the samples, for fear that the droppings may be scooped.
As of two weeks ago, the team has moved the operation to the next generation genome sequencing team, which is resequencing the samples using the Illumina NovaSeq platform. Initial bioinformatics analysis has already pointed to some interesting differences between the two reindeer that perished and the other, non-perishable reindeer.
This is not one of Santa’s.
However, these differences alone weren’t enough to explain why nine of the reindeer appear to be immortal.
Not wanting to leave the findings down to the mystery workings of elves and pixies, the team went back to the GridION, to try and spot any other changes that might have occurred, perhaps at the epigenetic level.
Sure enough, several methylations were identified in specific regions associated with ageing, which, unlike the Womble project of early 2018, did not appear to be linked to telomere degradation but were spread throughout a range of loci.
To probe further, the team went back to the droppings, to find out what effect the environment of the reindeer might have had.
We all know that reindeer like to eat mushrooms, but some are more magic than others.
Indeed, an entirely new species of mushroom was discovered among the samples through DNA analysis, with an associated diversification in gut microbiota that appear to have adapted to this addition to the reindeer diet. Comparison with modern day reindeer across all of their native ranges shows the microbiome of the nine immortal creatures to be completely independent of anything else found.
The magic is in the mushrooms
The team is now working to investigate whether this shift in diet was indeed the elixir for eternal life, as well as potentially linking any other changes to a gain in the ability to fly.
Expeditions are also underway to attempt to locate the mystical mushrooms. However, evidence from more recent samples suggests that, though the epigenetic changes to the reindeer DNA appear to be permanent, their diet and associated microbiota has reverted back to its original state pre-immortality.
It is thought that this rare food supply may have vanished forever, leaving only traces of its effect living on in the nine reindeer.
Red nose day
Another peculiar finding was telling.
In the newest of the reindeer samples, the team found a large overabundance of genes involved in the inflammation response, particularly those found to increase in expression in response to viral infections such as the common cold and flu.
The team found that this reindeer has undergone a unique duplication of several genes involved in immune related processes - and initial analysis suggests that it may show a hypersensitive nasal response to the cold weather up north.
An artist’s impression of the red-nosed reindeer.
Whether or not these findings hint at a reason for Rudolph’s red nose is anyone’s guess, as without photographic evidence it’s hard to know whether this is all just fallacy. Anecdotal reports from East Dereham have however pointed to a large degree of snot surrounding several carrot stumps left out last Christmas Eve.
Tellingly, the mince pies were left untouched...
Any trace of reindeer droppings at the site appear to have ceased from 1981 onwards, leading the team to speculate as to why they appeared here for such a long time - and what drove them to finally change their destination of festive relief.
Yet, the researchers are increasingly supportive of the idea - and they take some convincing - that these results might just point to a semblance of truth in the story of Santa and his fabled sleigh.
“How else can you explain nine immortal reindeer and a sleigh-load of droppings?” Concluded Dr. Deborah Donner.
This story is clearly a festive fabrication, but have a wonderful festive period and a happy new year!