[ad_1]
It sounds like a riddle Rudyard Kipling reportedly tackled in his Just So stories, but it turns out the reason rabbits jump isn’t rooted in fables but in genetics.
Researchers say that by studying an unusual breed of rabbit that walks on its front legs, they identified a key gene that is needed for animals to adopt a typical gait. For rabbits, as well as animals such as hares and kangaroos, it is the ability to jump.
“If you [were to] introduce the same mutation [seen in these unusual rabbits] in humans you wouldn’t suppress the jump but you will change our locomotion in another way, ”said research co-author Professor Leif Andersson from Uppsala University in Sweden.
Writing in the journal Plos Genetics, Andersson and his colleagues reported on how they made their discovery focusing on Alfort’s hopping breed of domestic rabbit. Rather than jumping, these animals adopt a “pear tree” posture and walk forward on their front legs. The breed is also known to have eye problems including blindness and cataracts.
Both characteristics were known from selection experiments to be caused by a mutation in a single gene. However, which gene contained the mutation was unknown.
To dig deeper, Andersson and his colleagues bred Alfort jumping rabbits with New Zealand white rabbits – a hopping breed – confirming previous theories that two copies of the mutant gene are needed for rabbits to lose their bounce.
The researchers then performed a genetic analysis of the rabbits, revealing that the inability to jump appeared to be due to a single position mutation in a gene known as RORB. Alfort’s jumping rabbits were found to have two copies of this mutation. However, the mutation has not been found in other breeds of wild and domestic rabbits, nor in a host of other mammals, including humans.
“DNA sequences that are important for function are highly conserved across species,” said Andersson.
Basically, Andersson said, the RORB gene gives rise to a protein that turns other genes on and off. If this gene is not working properly, he added, the production of other proteins in the spinal cord may not be properly regulated, affecting the way the spinal cord coordinates messages between the brain and muscles in the limbs. .
Indeed, other work by the team has revealed that rabbits carrying two copies of the RORB mutation do not have a detectable RORB protein in their spinal cord.
The team says their discovery is linked to previous work showing that mice that had a mutation in their RORB gene not only had eye problems, but an unusual duck-like walk.
However, Andersson said the RORB gene was not the only gene important for walking. For example, the ability of horses to roam, found in certain breeds such as the Icelandic pony, has previously been linked to a mutation in a gene known as DMRT3.
Arne Ludwig, professor of animal genetics at the Albrecht Daniel Thaer Institute at Humboldt University and the Leibniz Institute for Zoo and Wildlife Research in Berlin, who was not involved in the study, said that the gait was a complex trait.
“Several genes are involved and this study shows that RORB is one of them,” he said.
But, he added, the breeding of Alfort jumping rabbits is worrying given their multitude of disorders.
“Leaping rabbits would probably have no chance of surviving in the wild,” he said.
[ad_2]
Source link