Embryos, as small as the tip of a needle, enter a resting phase a few days after fertilization. This peculiar phenomenon called “diapause” was first reported more than 150 years ago. Huntsmen observed that roe deer mated in July/August, but embryo development was visible in the uterus no earlier than December. Despite intensive research, it has not yet been possible to conclusively decipher all the regulatory mechanisms of diapause. A widespread developmental trait, diapause is found in around 130 mammalian species. These not only exhibit large variation in duration of diapause, from several days up to a year, but also use different mechanisms by which the arrest and reactivation of the embryo are controlled. It is of great interest for today’s biologists, veterinarians, and physicians to understand how embryos arrest growth and then begin again, weeks or months later with no damage. State-of-the-art cell and molecular biology technology offers exciting new approaches to this question. Valuable basic information on the developmental biology of mammals can come to light. The overall goal of the conference is to provide a 21^st century perspective on the phenomenon of diapause. It will bring together international researchers from diverse fields to focus on a single but highly important biological problem providing evolutionary, physiological and molecular perspectives. Specifically, young investigators will have the opportunity to learn from those who have made major progress in the reproductive biology of diapause over the last decades. Understanding the rate of embryonic growth may reveal early discontinuous development as a trait common to all mammals. This is of particular interest in many species, including livestock and humans. Understanding diapause will provide novel information on its potential role in improving assisted reproductive techniques, in preservation of endangered species and in stem cell and cancer biology.

Main topics

• Evolution and diversity of diapause
• Embryo-uterine communication during diapause
• Molecular signals controlling cell growth in the embryo
• Future directions for studies of diapause (including stem cell biology and carcinogenesis)