A team of genetics researchers at the Donnelly Center in Toronto, Canada, has discovered that a large group of genes, up to several dozen, that supposedly perform similar functions in different species and organisms, are actually unique to the human species .
It is possible that in them is the explanation of how Homo Sapiens came to exist and evolve. The characteristic of these genes is that they encode a type of proteins known as transcription sources or TFs, which monitor genetic activity. What TFs do is identify specific pieces of DNA called motifs and use them as landing pads to bind DNA together and turn genes on or off. Some previous studies ventured the idea that TFs that are similar in different organisms also have similar shapes, even in species as different as the fruit fly and humans . But the new study by Professor Timothy Hughes of Toronto’s Donnelly Center for Cell and Biomolecular Research has revealed that this is not always the case.
According to the article published in the journal Nature Genetics , Hughes and his team describe a new computational method that allowed them to more accurately predict the motif sequences that each TF links in many different species.
The results reveal that some subclasses of TF are much more different at the functional level than previously thought . “Even among closely related species, there is a significant portion of FTs that are likely to bind to new sequences.
This means that TFs are likely to have new roles in regulating different genes, which may be key to species differentiation, “says Sam Lambert, the Hughes lab member who did much of the research. Research Even between chimpanzees and humans , whose genomes match 99%, there are dozens of FTs that recognize various forms between the two species in a way that could affect the expression of hundreds of different genes.
Lambert believes that these molecular differences could be the drivers of some of the differences between chimpanzees and humans . In order to review sequence motifs, Lambert developed new software that looks for structural similarities between FT DNA-binding regions that have to do with their ability to bind the same or different DNA motifs. If two TFs from different species have a similar composition of amino acids or protein-making building blocks , they will likely bind similar motifs.
When Lambert compared all TFs from different species and combined them with all available motif sequence data, he discovered that many human TFs recognize different sequences and therefore regulate different genes than versions of the same proteins do in other animals. .
The finding invalidates previous research that determined that nearly all human and fruit fly TF bind to the same motif sequences, which is a warning to scientists hoping to gain insight into human TFs through testing. study of their homologues in simpler organisms. Some of these TFs have to do with sexual dimorphism .
There are many visible and less obvious differences between the sexes that guide the choice of mate. They are decisions that have an immediate impact on reproductive success and that can also decisively influence physiology in the long term. The peacock’s tail or facial hair in men are classic examples of these characteristics.
Almost no geneticist studies the molecular bases of sexual dimorphism, despite the fact that it encompasses a series of characteristics that all human beings see and that fascinate us.
