A recent study by researchers from the University of Illinois-Chicago has uncovered a potential mechanism that induces the cessation of growth in fruit flies during puberty. This finding enhances our knowledge of animal development and carries implications for understanding human growth regulation, particularly in the context of early-onset puberty.
Growth cessation signals emerge during puberty
In the animal kingdom, all organisms initially start as single cells and experience a growth phase. The specific mechanism that ceases this growth has been largely undisclosed.
Notably, in humans, growth cessation signals generally emerge during puberty, with the process taking additional years to complete. Puberty onset has been occurring at progressively younger ages, necessitating a deeper understanding of the underlying mechanisms driving this shift.
Study author and biological sciences professor at the University of Illinois-Chicago, Alexander Shingleton, said that the initiation of puberty is occurring at increasingly earlier ages. However, to comprehend the reasons behind this shift, it is essential to grasp the underlying mechanisms.
To comprehend a complex biological process, scientists studied fruit flies, which undergo a puberty-like transformation from larvae to adults. While many biologists speculated that larvae stop growing at a specific size, triggering adulthood, doubts arose about whether fruit flies utilized the same mechanism as other insects such as the kissing bug that depends on a stretch receptor on its abdomen to track size.
Researchers proposed that a steroid hormone, ecdysone, akin to human hormones like estrogen and testosterone, might play a crucial role in fruit fly growth, diverging from the stretch receptor mechanism observed in insects like the kissing bug.
Ecdysone responsible for controlling growth on fruit flies
The growth cessation in fruit flies is not determined by body size but is instead controlled by a “stop growing” switch activated by the gland producing ecdysone. The gland regulates ecdysone production based on nutritional information received during the larval stage.
Once ecdysone reaches a certain level, the gland becomes self-regulating and no longer depends on external cues. This shift from external dependence to self-regulation is considered the critical factor leading to the cessation of fruit fly growth.