IISER Pune is happy to announce:

Second institute colloquium:

Venue: Sir CV Raman Auditorium, Lecture Hall Complex IISER Pune

 

Abstract: Different cell types in a given animal, such as heart cells and brain cells display different behaviors because they express different sets of genes. Yet, they all have DNA with essentially the same sequence and thus the same set of genes. How is it that the same DNA is used to generate different cell types? Which genes are on and which genes are off is controlled in part by how their underlying DNA sequences are packaged. DNA is packaged by wrapping it around specific proteins called histones to generate bead-like structures called nucleosomes. Strings of nucleosomes are then further folded to condense the underlying DNA and make it less accessible. Structures called heterochromatin are thought to be particularly effective at compacting strings of nucleosomes and turning off the underlying genes. A few years ago we discovered that nucleosomes, rather than acting as rigid packaging units act as shape-shifters to regulate access to the wrapped DNA. Around the same time we also found that proteins named HP1 proteins, which are core components of heterochromatin, can sequester packaged DNA into phase-separated droplets. Within these droplets the HP1 molecules are dynamic and display liquid-like properties. In my talk I will discuss the experiments that led to these findings. I will also discuss how these unexpected biophysical properties of the packaged genome are leading to new ways of conceptualizing genome regulation.