Year 1 - Development
Thursday, April 23rd, 2015, 12 noon
2-101 Nils Hasselmo Hall
"Two for the price of one: twinning – the ultimate regeneration"
Claudio Stern, Department of Cell and Developmental Biology, University College London
Gastrulation has been called the most important time in your life because it is when the embryo sets up its three main layers of cells, starts to specify its primary body axis, and many cells first become committed to their fates. Remarkably, until the start of gastrulation, bird and mammalian (including human) embryos can still give rise to multiple individuals (twins). This reveals not only a "pluripotency" of fates, but also the striking potential of the embryo to self-organize into a complete organism. Twinning can be viewed as an extreme case of regeneration: parts of the embryo can regenerate the entire body and form another individual. But this raises a new question: what mechanisms prevent this from occurring more regularly during normal development? We will review some recent progress in understanding the molecular and cellular mechanisms that coordinate fate, polarity, cell movements, and pattern in the embryo that also regulate twinning.