The hormonal surge of puberty may begin with a kiss in more ways thanone.

A new study shows that a molecule produced by the aptly named gene KiSS-1may trigger the hormonal chain of events that primes adolescent boys and girlsfor their reproductive years.

The findings may help explain how this hormonal system, which is active atbirth, becomes dormant during early childhood and then re-emerges with avengeance for the beginning of adolescence.

"Puberty is critical to human development. And while there is a fairlygood understanding of how the endocrine system regulates the hormones involved,just how and when the brain activates this process has been a greatmystery," says researcher Tony Plant, PhD, director of the Center forResearch in Reproductive Physiology at the University of Pittsburgh School ofMedicine, in a news release.

Plant says a better understanding of the biological and brain processesinvolved in the onset of puberty may eventually help prevent early puberty ortreat delayed puberty in some children.

KiSS Triggers Puberty

In the study, which appears in the Feb. 8 edition of Proceedings of theNational Academy of Sciences, researchers looked at the role of KiSS-1 inthe reproductive system of monkeys, whose reproductive system closely resembleshumans'.

Previous studies have suggested that a gene called GPR54 is defective inchildren with a disorder that delays the start of puberty. The start of pubertyis marked by the release of gonadotropin-releasing hormone (GnRH), whichstimulates the sex organs (the ovaries or testes) to make the sex hormones.

Based on these findings, researchers looked at the ability of KiSS-1 to turnon GPR54 and stimulate the release of GnRH in adolescent monkeys.

They found that injections of the molecule produced by KiSS-1 triggered arobust release of GnRH in the monkeys.

"We now have very good evidence that the GPR54 gene and its switch, thekisspeptin protein molecule produced by KiSS-1, are key to the initiation ofpuberty, when GnRH is released," says Plant. "However, it's unlikelythat they act alone. Other signaling systems, some of which have probably yetto be identified in humans, help control GnRH release in primates."