A recent study highlights how a single gene in Atlantic salmon can significantly affect the onset of puberty, which is crucial for their life cycle and survival.
A recent investigation conducted by the University of Helsinki reveals that a particular gene in Atlantic salmon plays a vital role in determining the timing of puberty, a significant aspect for their life cycle and survival.
Researchers found that the gene, referred to as vgll3, functions as a master regulator, managing thousands of other genes associated with different phases of salmon sexual development.
“Think of it as a single switch that decides if puberty starts at age 13 or 20 for humans. Vgll3 serves a similar purpose in salmon, impacting factors such as the onset of reproductive cell development, growth patterns, and behavioral shifts. Our findings illustrate how variation in one gene can lead to profound changes in complex traits like puberty or age of maturity,” explains Associate Professor Jukka-Pekka Verta, currently at Nord University in Norway, who performed this research during his post-doctoral study at the University of Helsinki.
This discovery not only sheds light on the evolution and variation of complicated traits like the onset of puberty but also emphasizes a phenomenon known as “pleiotropy,” where one gene influences multiple traits, akin to a conductor leading an orchestra.
The Vgll3 gene is associated with puberty timing in humans, albeit with a lesser impact. In humans, this same gene plays a more substantial role in a serious skin disease known as lupus, which predominantly affects women more than men.
Hydroelectric dams can influence salmon maturation
The implications of these findings are significant, particularly regarding how human activities like the construction of hydroelectric dams can lead to swift evolutionary changes in salmon populations.
As a migratory species, salmon require unobstructed routes between their spawning habitats in rivers and their feeding grounds in the ocean. Many hydroelectric dams lack functional fish ladders, which can obstruct access to upstream breeding grounds.
“If the spawning environments below a dam are only conducive to smaller salmon, there may be strong natural selection pushing against the ‘late maturation vgll3 variant.’ This adaptation process allows the salmon population to adjust to new conditions, but it can simultaneously diminish genetic diversity, which may have adverse long-term effects. Now we have a better understanding of the other genes and mechanisms that might be influenced by such alterations,” notes Professor Craig Primmer from the Faculty of Biological and Environmental Sciences at the University of Helsinki.
By changing the prevalence of specific vgll3 variants, natural selection can lead to substantial modifications in traits such as size, egg quantity, and behavior. This research highlights the significance of fundamental evolutionary studies for managing wild populations and forecasting how environmental changes affect ecosystems.
