The mice that almost learned to talk

Genetic research about a family of mutes in England, led to the discovery of a gene responsible for the development of the ability to speak in humans. When the gene was engineered into the DNA of mice, they developed different learning and communication abilities than normal mice

For most of us speaking is second nature. We cannot remember a time when we could not open our mouths and communicate with the environment. This is part of our heritage as humans - the richness of the human vocabulary, and our ability to express ourselves. As the famous Indian leader Mahatma Gandhi said, "Language is an accurate reflection of the character and growth of its user". A human being who is unable to communicate with his environment loses his identity and character. Unfortunately for the K family, that's exactly what they lost.

The unique family was discovered in the nineties in London, and has since been used as a pilgrimage center for neuropsychologists and biologists from all fields. Of the thirty members of the family, spanning three whole generations, about half are unable to speak clearly. Upon careful examination of the family, it became clear that at least part of the problem lies in the fact that those semi-mutes have lost the most basic ability necessary for speech - the synchronization between muscles.

The act of speaking is so instinctive for us, that we forget that it involves the movement of dozens of muscles - ribs, throat, palate, tongue and facial area. All of these move in perfect harmony with each other, resulting in us being able to pronounce syllables and words with impeccable accuracy. But in the patients from the K family, the synchronization between the different muscles has been lost, and they are unable to form the complex sounds on which human language is based.

Since these are members of the same family, many researchers believed that a hereditary mutation was involved, and if they insist on a nature, it will be possible to understand the origin of the development of human language. Indeed, in 1998, the mutation that distinguished the sick family members from the healthy ones was revealed - a small and simple mutation in the FOX2P gene, which disrupts its function.

This discovery led to the belief that the FOX2P gene is partially responsible for humans' ability to speak, and spurred many researchers to study the gene and the variety of different forms in which it appears in creatures other than humans. Since the 2s, various derivatives of FOXXNUMXP have been discovered in chimpanzees, mice, songbirds, bats and even in semi-preserved DNA that came from our millions of years old relative - the Neanderthal man.

But what is the role of that garden, without which we lose a large part of our humanity? We still don't know exactly. It seems to be necessary for the normal development of the brain and lungs, but also for maintaining brain functions. When the birds called "Zebra Pink" learn new songs, the FOX2P gene in their brains starts to work and express itself more strongly. It is possible, therefore, that kindergarten helps us learn the principles of language in our youth, until we can speak for ourselves.

The gene itself is nothing more than production instructions for the protein, and it is surprising to see that the FOX2P proteins are very similar in most of the creatures reviewed so far. The human FOX2P protein

It differs from the chimpanzee's protein by only two amino acids (two of the Lego blocks that make up the entire protein). It differs from the protein of mice by three amino acids, and from that of zebra finch birds by only seven amino acids. What do the differences mean? We are not sure of this yet, but at the end of May of this year, an extraordinary study was published, which demonstrated that even the smallest difference of three amino acids, can give the organism distinctly different properties.

Wolfgang Annard, the same researcher who decoded the genetic sequence of the human FOX2P gene and identified the main changes that distinguish it from other animals, decided to do a particularly bold experiment, the results of which he could not predict in advance. He created genetically modified mice, in which the human FOX2P gene was present, instead of the corresponding version of the gene of murine origin. If the human gene does help humans to develop their own language, then we would expect that the upgraded mice would be able to communicate with each other differently, and perhaps even demonstrate a change in brain activity indicating the first buds of the ability to "speak", or improved expression. Surprisingly, that's exactly what Annard found.

When Annard compared the genetically modified mice, which contain the human gene, with their normal mouse friends, he saw that the "improved" mice produced nerve cells capable of learning a sequence of physical actions better, faster and more easily. These neurons are located in the same areas of the brain where the effect of FOX2P is expressed in other species. And when Annard tested mice that carried one defective copy of the gene, he discovered that the ability of the nerve cells in that area to learn was severely impaired. This fact may explain why humans, in whom the FOX2P gene is damaged, have difficulty speaking, and why songbirds suffering from a similar damage fail to imitate the songs of their friends.

The most interesting discovery came from comparing the whimpers and sounds made by the young mice. When mouse pups are removed from their mothers, they whine and scream at high frequencies. Annard's genetically modified mouse pups, when removed from their mothers, also whimpered, but in different patterns and frequencies than the normal mice. As if - and only as if - they learned a new language in which they could express themselves.

What does the experiment mean? Is it possible that Annard's improved mice will be able to speak under the right stimulus? The chances of that are slim, if not zero. Annard himself admits that the sounds the mice make are more similar to a baby's cooing than any other sound. He is convinced that we will never be able to fully reproduce human speech in mice. The different evolution that humans and mice have undergone has resulted in irreconcilable differences in the shape of the lips, tongue, palate, vocal cords and other factors necessary for clear pronunciation of syllables. But behind Annard's uncompromising determination, stand the new mice he created, chirping with voices very different from their usual friends. And maybe, just maybe, they understand a little more than they reveal to the outside.

The article was published on the blog ofRoey Tsezana