Review: The Role of Zinc Signaling in Reproduction

Human infertility has become a serious medical and social issue worldwide, especially in developed countries. Numerous assisted reproductive technologies (ARTs) (e.g., artificial insemination [AI], in vitro fertilization [IVF], and intracytoplasmic sperm injection [ICSI]) are widely used to treat infertility, but when embryos produced using these techniques are transferred, the pregnancy outcome is only approx. 20–50%, necessitating further improvement in ARTs. Many factors (including zinc) affect successful fertilization, further embryonic development, and the establishment and maintenance of pregnancy. Zinc signaling has many physiological functions in various types of cells, and it is thus speculated that zinc signaling has an important role in the abovementioned reproductive events, even in germ cells and reproductive tissues. Prior studies demonstrated that zinc deficiency results in a number of anomalies in the formation and maturation of spermatozoa, ovulation, and fertilization. During pregnancy, zinc deficiency causes spontaneous abortion, pregnancy-related toxemia, extended pregnancy or preterm birth, malformations, and retarded growth. The molecular mechanisms underlying zinc signaling in reproduction are not yet clear. In this chapter, we summarize the current knowledge about zinc signaling in reproduction—mainly in mammals—and we discuss recent advances in this field.