NOVA1 - The Mystery of the Gene That Made Mice Squeak Strangely

The Gene That Made Mice Squeak Strangely explores the challenge of understanding the evolution of human language. Referencing this study, researchers discovered a specific gene, named NOVA1, developed significantly between 250,000 and 500,000 years ago. Scientists then took that human version of NOVA1 and put it into mice. What did they discover? The mice then made more complex sounds.

Imaging of a mouse's brain, where the cells producing NOVA1proteins are colored green.

I find the most intriguing part of this research to be that out of 20,000 protein-coding genes, almost all produced proteins that were identical in most mammals. There were only 23 of these that were identical in mammals except for human beings. That's 0.115%. NOVA1 gained attention for being one of those 23. While it certainly is important to note, it's not a single gene that allowed us to develop the language abilities we have now, but many mutations over millions of years.

What is also fascinating about the NOVA1 gene is mammalian life appears dependent on its presence. A mouse without it is not viable, but there was little to show it played any significant role in our evolution.

Fossils and Ancient DNA

   

 Human evolution. The history of primates, which led to the beginning of the Homo sapiens as a distinct species. According to Dr. Llamas, Dr.Willerslev and Dr. Orlando the field of human ancient DNA, also known as aDNA has become a fully genomic discipline, which is changing our concept of human history. There has been a recent discovery in the world of aDNA. Fossils of an Asian woman have been linked to early Americans. A DNA sample was extracted from the skullcap of a southwestern Chinese female. The estimated age of the fossil is 14,000 years. Geneticist Bing Su has recovered almost all of the individual's mitochondrial DNA, which is typically inherited from the mother and around three percent of the nuclear DNA, which is inherited from both parents. Using this, Su found this individual carried genetic similarities to ancient people from the Americas (~12,000 years ago) Furthermore, Su's team stratified the the identity of the woman to exhibit genetic continuity to present day populations. 

Gene in Brain Linked to High Human Intelligence

A team of European scientists conducted studies on a gene within the human brain, known to be connected with the high intelligence of humans when compared to other species. The scientists inserted the gene, ARHGAP11B, into organoids of chimpanzees which are the closest living relatives to humans. An organoid is a lab-grown group of cells or tissues that have some of the functions of an organ. Organoids were used for the study since scientific experiments involving altering genes have been banned in Europe out of ethical concerns. The chimpanzee organoids introduced to the ARHGAP11B gene showed an increase in neurons and brain stem cells related to brain growth. The scientists in the study found that the gene could enlarge a primate's brain but say further study is needed to determine the size of a role in human brain evolution. Likewise, they also found that when the gene was removed or inhibited in human organoids, the functioning of the cells decreased to the level of a chimpanzee. 

This study showed just how important the ARHGAP11B gene is to the development of the human brain. I think that this study gave great incites into how the human brain evolved and the genes responsible for its high-functioning. I am glad that we have the technology like organoids to develop experiments that we can use to study genes like this, and I how that more studies on this gene are done in the future. I'm sure there is a lot to learn from this gene and even medical applications it has concerning brain development, functionality, and disorders.