Insect metamorphosis may reveal the key to the transition to puberty

This is the case in both humans and insects Body mass It plays a crucial role at the beginning of the transition from adolescence to adulthood. This process is triggered when a certain critical weight is reached, which in the case of insects drives growth Beginning of metamorphosiswhereas in humans it marks that Beginning of adolescence.

Starting puberty at the right time is crucial for the development of the individual sufficient energy reserves It is vital for reproduction. Likewise, insects must reach a minimum weight in order to successfully develop adult structures and reproduce. Both processes are inextricably linked Steroid hormone synthesis.

However, the signals linking body mass to puberty and metamorphosis remain a mystery.

Now a study led by the Institute of Evolutionary Biology (IBE-CISC Universidad Pompeu Fabra) sheds light on the molecular processes that connect this Body mass with hormone production, which initiates metamorphosis and puberty. The results of the work were published in PLOS genetics.

When insects reach their final juvenile stage and reach their critical mass, steroid synthesis is activated, thereby triggering the metamorphosis process. However, it is not known by what mechanisms it is triggered.

Xavier Franch MarroPrincipal investigator of the IBE and co-author of the study, emphasizes that “understanding the relationship between body mass and hormone synthesis in insects can give us clues to control the onset of puberty and develop therapies to prevent it.” premature puberty“.

To solve this puzzle, the IBE team manipulated various signaling pathways in the Flour beetle (Tribolium castaneum). Surprisingly, by inactivating the TGFß signaling pathway Transforming growth factor beta), observed that instead of initiating metamorphosis, the beetle larvae remained in the juvenile state until their death.

“Compared to humans, without activating this pathway, it is as if we would remain in a youthful state throughout our lives without stopping growth,” he comments. David MartinPrincipal investigator of the IBE and co-author of the paper.

Signaling pathways

With these results, the authors revealed the signaling pathways that trigger steroid production at the end of the juvenile stage, thus initiating metamorphosis. But which factor activates these pathways exactly at the moment when the critical weight is reached?

It is known that body mass plays a crucial role in humans as they begin the transition to adulthood. Consequently, diseases that affect body weight, such as: Anorexia or obesitycan delay or bring forward the onset of adolescence.

“We have observed a connection between body mass and the activation of these signaling pathways and therefore want to identify the proteins that are expressed in relation to body weight,” explains Franch.

The key lies in myostatin

The key lies in the Myostatin, a growth factor This occurs during muscle development and activates the signaling pathways that trigger metamorphosis when the critical weight is reached.

This factor acts as a link between steroid production and critical weight, warning the body that an optimal weight has been reached and we can begin metamorphosis or puberty.

Xavier Franch-Marro (IBE)

“This factor acts as a link between the production of steroids and the critical weight, warning the body that an optimal weight has been reached and we can begin metamorphosis, or in our case, adolescence.” sufficient energy reserves“says Martin.

According to Franch, “The signaling pathways responsible for activating metamorphosis in insects are the same as in humans. Therefore, these results could provide clues about our transition to puberty and open the door for future research on human health,” he emphasizes.