Keeping puberty on time: novel signals and mechanisms involved.

Puberty is the culmination of a complex series of maturational events that lead to the completion of sexual and somatic maturation and the acquisition of reproductive competence. This key developmental transition, which defines the boundary between immaturity and adulthood, is under the control of sophisticated regulatory networks that impinge upon the brain centers governing the reproductive axis. These networks are sensitive to earlier maturational events, such as brain sex differentiation, and dynamically regulated by a plethora of hormonal factors and environmental signals, which are essential for the fine-tuning of the tempo of puberty. While much knowledge on mammalian puberty had been gleaned during the last decades, important recent developments have substantially expanded our understanding of the neuroendocrine and molecular mechanisms governing puberty onset. We will provide here a synoptic account of some of these important advancements, including the identification of the essential roles of hypothalamic kisspeptin signaling, and some of its putative partners, in pubertal maturation, the characterization of novel mechanisms involved in the metabolic regulation of puberty, and the recognition of the potential roles of epigenetics and miRNA-related pathways in the central control of puberty. It is expected that further progress in these and related areas will follow in the coming years. This will permit a better understanding of the physiological mechanisms responsible for pubertal timing and will help to decipher the pathophysiological basis for pubertal alterations in humans and wildlife species.