Selective breeding by humans has led to some incredibly strange and unfortunate pets over the years, and the Alfort jumping rabbit is one of the strangest.
This rare breed of rabbit does not jump or walk like any other rabbit or hare that exists. When the savior is ready, he throws his hind legs into the air and bounces forward on his front legs, like a human acrobat walking on his hands.
While this may seem like a fun shot, it sadly comes with other debilitating issues. Now, the only rabbit that can’t jump properly has helped us better understand the genetics of jumping in mammals.
Crossing a single male author with a single white female from New Zealand and crossing the resulting offspring, the researchers raised 52 bunnies, 23% of whom carried two copies of the mutant gene similar to the original parent. These figures match the expected statistics when there is only one recessive gene involved in a mutation.
By grouping the DNA of young authors and non-authors, the researchers used genome-wide sequencing to compare the two groups. In the end – as they predicted – there was only one gene that stood out.
The cause of the author’s defective jump appears with a mutation in an evolutionary conserved site of a gene known as RORB, which provides instructions to mammalian cells to create certain proteins.
RORB proteins are generally found throughout the rabbit’s nervous system, where they help turn the genetic code into a protein-building template. This particular mutation, however, causes a particularly sharp decrease in the number of neurons in the spinal cord that can produce this protein.
In fact, two copies of the RORB mutation did not cause any protein in the spinal cord and this was linked to the inability to jump. Other litter rabbits able to jump with their hind legs showed no protein loss.
The authors conclude that the RORB gene must be what allows rabbits to bind around. It could also be the key to other mammal jumps.
Over the years, there has been a great deal of scientific interest in special physiology and biomechanics that allow mammals (such as kangaroos, rabbits, hares, and some mice) to jump, but genetics have rarely been taken into account. underlying this feat.
One of the few recent studies has found mice with the same RORB mutation that the author rabbits cannot jump as normal either. Instead, these rodents move their front legs like a duck, with their tails and hind legs raised in the air.
“I spent four years looking at these mice making small hands and now I see how a rabbit does the same foot,” neuroscientist Stephanie Koch of University College London told Science News. “It’s fantastic.”
Koch’s study of rabbits is the first to describe a specific gene needed to jump or jump, and it aligns very well with what has been observed in mutant mice.
Similar to mutant rodents, the author rabbits also show other anatomical defects beyond their strange gait. Many are born blind and develop cataracts in their first year of life. Harmful RORB mice also show retinal degeneration.
In mice, the RORB gene appears to play an essential role in differentiating cells from both the cerebral cortex and the retina. It can also do something similar to the spinal cord, which is involved in the regulation of sensory information and locomotion among mammals.
As such, this lack of protein may be what causes the hind legs of rabbits and mice to lift rather than jump. In author rabbits, for example, the RORB mutation appears to cause defects in the differentiation of spinal cord interneurons, although it is not yet clear whether this is causing strange locomotion.
“In addition to its expression in the spinal cord, RORB is also expressed in many regions of the brain such as the primary somatosensory, auditory, visual, and motor cortex, in some thalamus and hypothalamus nuclei, in the pituitary gland, and in the pituitary gland. upper colliculus, “the authors write.
“Therefore, we cannot rule out the possibility that an alteration in RORB function in the brain may contribute to the locomotion phenotype characteristic of sauteur rabbits.”
The effects of the RORB mutation will require further study, but it is obvious that it is involved in some way. This was the only variant identified in the entire rabbit genome sequence that had an impact on the jump.
While there may be more genes involved in the rabbit jump, it seems that poor safety rabbits have pointed us in the direction of one.
The study was published in PLOS Genetics.