These stories have nothing in common other than that they are fascinating examples of the way animals have evolved to suit their environments and lifestyles.
Researchers say they have discovered how Tibetan antelopes are able to run hard and fast despite living at altitude, and why Siamese fighting fish fight like they do.
In the first case, it’s a bit about staying young.
A study published in the journal Science Advances suggests that Pantholops hodgsonii has overcome oxygen deprivation on the high-altitude Tibetan Plateau through an unusual adaptation in which it permanently expresses a form of haemoglobin that other members of the cattle family only express as juveniles, or when under extreme oxygen deprivation.
Through a comparative genomic analysis with other bovids, Anthony Signore and Jay Storz from the University of Nebraska, US, found that the region that encodes for the adult form of haemoglobin was deleted in the antelope’s ancestor, causing the juvenile form of the protein, which has a higher oxygen affinity, to take its place in adult red blood cells.
In other words, they say, a reversible response to oxygen deprivation previously documented in adult goats and sheep became a permanent genetic fixture in a mammal that is native to a region that ranges between 3600 and 5500 metres above sea level.
Through in vitro experiments, they confirmed that the antelope’s haemoglobin does have a much higher oxygen affinity than that of all other bovids, perhaps explaining how it can run at 70 kilometres an hour over great distances, at altitudes where the partial pressure of oxygen is roughly half that at sea level.
In the second study, published in the journal PLOS Genetics, researchers from Japan, Taiwan, Saudi Arabia and the US reveal that when Siamese fighting fish are fighting, the gene expression in their brain cells starts to align.
Betta splendens is famous for its aggression, but male opponents modify their actions to match each other’s behaviour – leading to tightly synchronised battles – and typically stop fighting after assessing the other’s abilities to avoid any serious injuries, the researchers say.
When they analysed their brains, they observed that the opponents had similar changes in gene activity related to learning, memory, synapse function and ion transport across cell membranes.
This was specific to a fighting pair and became stronger after fighting for an hour, compared to 20 minutes, suggesting the degree of synchronisation is driven by fighting interactions.
Similar mirrored behaviours occur during mating, foraging and cooperative hunting, and these may also trigger synchronised brain changes in the pairs of animals.
“One of my future plans is to elucidate what happens in the male-female interaction of fish on the molecular level,” says lead author Norihiro Okada, from Kitasato University, Japan.
Nick Carne is the editor of Cosmos Online and editorial manager for The Royal Institution of Australia.
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