Biology

Dr Sreelaja Nair
TIFR, Mumbai

Abstract: 

The one-cell embryo is a deceptively simple entity during the early part of its life. From this one cell, a multicellular, three-dimensional animal eventually emerges through the process of embryogenesis. Decades of forward and reverse genetics have yielded a fairly clear view of the evolutionarily conserved molecular pathways that are essential for normal embryonic development. Yet, an unambiguous understanding of how complexity emerges in a multicellular embryo as development proceeds after fertilisation remains poorly understood. My group uses zebrafish embryos to uncover some of these early fundamental principles that set in motion embryogenesis in a vertebrate embryo. We find that zebrafish embryos use conventional epigenetic information in perhaps unconventional ways to ensure transfer of critical molecular information immediately after fertilisation. We also find that early in development embryos can and must regulate the sizes of their cells; failure to do so can be disastrous for eventual patterning and viability. How do embryos measure the sizes of their cells? I will discuss some emerging results from my group that sheds light on the inherent complexity of vertebrate development, particularly during the earliest phases, when embryos have been typically described as a collection of cells.