All the cells of our body, as with the rest of the species, have defined functions to guarantee their survival, as well as to ensure the correct functioning of all our organs. They stand out precisely for the fact that they are essential basic components for life , which are present in all living organisms.
But are the cells of all human beings the same? What similarities do our cells have to those of, for example, a mouse? A fish? And a worm?
The comparison of the different types of cells in different species, along the tree of life, can be of great help so that biologists can be able to understand how they arose and how the types of cells have adapted to the needs functionalities of the different forms of life.
It is something that, in recent years, has been of great interest to evolutionary biologists, thanks to the fact that technology offers new possibilities when it comes to sequencing and identifying all the cells present in whole organisms .
And in response to this opportunity, the Stanford University bioengineering laboratory has developed an algorithm capable of linking similar cell types across evolutionary distances , using a specially designed method to compare cell types in different species .
To carry out this research, the team of scientists used a total of seven different species to compare 21 different pairings. They were able to identify the cell types present in all species, including both their similarities and their differences.
Comparison of the different types of cells
The idea came when Bo Wang, an assistant professor of bioengineering at the university, walked into the lab one day and asked if it was possible to analyze cell-type data sets from two different worms.
From that point on, the scientists realized that although they thought both worms must have similar cell types, when they tried to analyze them using standard techniques, the method simply did not recognize them as similar.
Based on the results obtained, the researchers wondered if the cell types were too different to coincide between species, or if it was a problem related to the technique. Thus, in order to better match cell types between species, Alexander Tarashansky, a graduate student in bioengineering, began work on the algorithm.
And how does this algorithm work? Take as an example the comparison of a sea sponge with a human. Obviously, it is not clear which sponge gene could correspond to which human gene, since, as organisms grow and evolve, genes duplicate, change, and duplicate again. “And now we have a gene in the sponge that could be related to genes in humans.”
Until now, scientists were trying to find a one-to-one gene match for the data match. But, now, the mapping method designed by the researchers is able to compare the sponge gene with all potentially corresponding human genes. Later, the algorithm is in charge of finding out which one is correct .
Using this new mapping approach, the scientists discovered a number of conserved genes and families of cell types in all species . And the results obtained also suggest that there is a strong conservation of the characteristics of neurons and muscle cells from very simple types of animals, such as marine sponges, to much more complex mammals, such as mice and humans.
As Wang states, “Evolution has been understood using genes and traits of organisms. But now we are at an exciting tipping point to bridge the scales by looking at how cells evolve. “
