An exquisitely human genetic variant and favored by evolution seems to change the way the mice that acquire it produce sounds.
A genetic variant present in almost all human beings, but not in their extinct cousins Neanderthal and Denisovian, It makes the sbucts of the mice becomes more complex in which it is introduced. Scientists suspect that this modification may be one of the many DNA alterations that have played role in the development of human language. The research led by Yoko Tajima of the Rockefeller University’s molecular neuro-blucology laboratory in New York was published on Nature Communications.
Our specialty. The origins of language remain mysterious because they are difficult to reconstruct from the archaeological evidence only. Although some of our narrow “relatives”, such as the Neanderthals, had anatomical characteristics that allowed the production and understanding of spoken sounds, and shared with the sapiens the variant of a gene (Foxp2) connected to linguistic skills, Only the brain of modern man shows an expansion in the crucial regions for language.
A new track. The new study has identified an exclusively human and practically omnipresent genetic variant in our species – a different version of a gene known as Nova1, crucial for neural development – which may have had an important role in the development of spoken language. Introduced in the mice, the variant altered their squeaks, modifying the way the rodents communicated. In short, we could be in front to one of the “genes of language”, even if certainly one of the many.
Disorders, if missing. Robert Darnell, Rockefeller University’s neuroscientist at the head of the laboratory where Tajima worked, knew the Nova1 gene from the 90s: he had sensed that he could be linked to language after having treated, as a neurologist, A boy containing only one working copy of the gene, who presented autism and serious linguistic problems and movement. Subsequently, other studies have confirmed that all human beings have a version of the gene distinct from that of the Neanderthals and from the one who presented the Denisovians.
A single letter of difference. Nova1 produces a binding protein of the RNA (i.e. able to establish links with the RNA) in the neurons that has a role in brain development and neuromuscular controlat the basis of spoken language. The human version of the protein, the variant I197vdiffers from the version of Nova1 present in all other mammals and in birds only For a single amino acid.
An advantage that we keep tight. The variant of the Nova1 Gene is present in practically every modern man: the working group has set 650,000 sequential genomes on several genetic databases and has not only found it in 6 people.
It must therefore have been there strong selective pressure that has favored the spread of this variantprobably in the last 300,000 years, after the separation of our ancestors from those of Neanderthal and Denisoviani. The modification of the gene must have been so advantageous that it becomes practically universal.
Changed calls. Yoko Tajima used the CRISPR technique to replace the version of the Nova1 gene present in mice neurons with the human variant. The analysis of the ultrasonic sbucts of the rodents have shown that The mice with the humanized version of the Nova1 gene had altered vocalizations and different from the “normal” ones, when they were separated from their mothers. And that, in the presence of a female of mouse in heat in the same cage, the male mice bearing the mutation produced more complex courtship calls.
We are only at the beginning. Therefore the variant of the Nova1 Gene may have contributed to making the difference in our linguistic skills (given that the theme of Neanderthal and Denisovian communication methods is, and remains, complex). Now the authors of the study want to understand how the genetic modification introduced changes the individual cells of the cerebral regions of the mice involved in the production and understanding of vowels.
