Key Points:
- A specific gene in zebrafish has provided clues to the evolution of social behaviors in humans and domesticated species.
- Researchers say zebrafish with the gene show an increased tendency to interact with others.
- The gene is also responsible for distinctive facial changes in later life.
Researchers at Queen Mary University of London have singled out a gene in zebrafish that may provide clues to the evolution of social behaviors in fish, domesticated species and even humans.
The research, published in iScience, focuses on the baz1b protein. Domesticated species, such as dogs and cats, show variation in the baz1b gene compared with their wild type counterparts. These genetic changes correlate with physical and behavioral traits, including smaller facial features such as skulls and teeth, as well as being more socio-positive, less aggressive, and having less fear.
Similarly, humans “domesticated” themselves after we split from Neanderthals and Denisovans. In doing so, we experienced similar physical and behavioral changes. Those changes have linked to the fact that domesticated animals have fewer neural crest stem cells.
In this research, scientists examined the impact of removing baz1b gene function from zebrafish, and what effects, if any, that would have on neural crest development and social behavior.
According to the study results, the mutant zebrafish were found to be more socially prone than their counterparts with functional baz1b. They showed an increased tendency to interact with members of the same species, although the differences between the two types of zebrafish were no longer observable once the fish were 3 weeks old.
As well as being more sociable, the mutant zebrafish showed distinctive facial changes in later life. These included altered eye length and width, a protruding forehead, and a shorter snout. This was accompanied by reduced anxiety-associated behaviors. The mutant zebrafish also showed mild under-development of the neural crest at larval stages.
Ultimately, the research team concluded that the baz1b gene in zebrafish impacts both morphological and behavioral characteristics associated with the domestication syndrome in other species.
“This study offers an interesting perspective into the origins of how we interact with others,” said lead study author Caroline Brennan, professor of molecular genetics at Queen Mary University of London. “While carrying the conclusions from zebrafish over to other vertebrates might be challenging, comparative studies such as these give insight into the evolution of human cognition.”
Information provided by Queen Mary University of London.