Mammalian genomes contain hundreds of lamina-associated domains (LADs), which are large, often megabase-sized heterochromatin domains that are anchored to the nuclear lamina (NL). Even though LADs play a key role in the spatial organization of the genome and potently repress gene activity, it is not yet understood how their interactions with the NL are encoded in their DNA. Here, we investigated the principles that govern LAD-NL interactions by taking a "LAD scrambling" approach. This approach relies...
Proximity Copy Paste (PCP) : A new method to map the 3D organization of chromatin
Proximity Copy Paste (PCP): A new method to map the 3D organization of chromatin
Understanding the principles of three-dimensional genome organization is essential to comprehend genome maintenance, expression, and duplication. Current Hi-C based methods use fragmentation of crosslinked chromatin followed by proximity ligation to detect DNA molecules whose extremities can be ligated together. While powerful, these approaches are limited because only ligatable, pairwise interactions are mapped,...
Orateur:
Shan Gao (Ocean University of China)
Genopolys Amphitheater
de novo methylation of N6-methyladenine (6mA) showcased in the unicellular eukaryote Tetrahymena
DNA N6-adenine methylation (6mA) is rediscovered as an important epigenetic mark in eukaryotes. It however remains unclear what the de novo methyltransferases (MTases) are and how they fulfill their biological functions. The binucleated Tetrahymena thermophila happens to possess a unique time window for the study of de novo methylation, when the 6mA-free zygotic nucleus develops into 6mA-positive new macronucleus (MAC). In this study, we found that the MT-A70 family members, AMT2 and AMT5, are not...
Orateur:
Ashley Albright (University of California, San Francisco - Wallace Marshall lab)
Genopolys Amphitheater
Patterning and gene expression in established and emerging model systems
The regulation of gene expression is crucial for all living organisms. Much of our understanding of the regulation of gene expression comes from early embryonic development in Drosophila melanogaster. However, understanding the regulation of gene expression is challenging due to the need to capture expression levels and patterning information simultaneously. Upon conducting single-nucleus RNA-sequencing in maternal null dCTCF, an insulator protein, embryos we found that early embryonic nuclei can...
Telomere-to-telomere assemblies uncover secrets of ape sex chromosomes
Evolution of ape sex chromosomes has remained enigmatic due to their highly repetitive nature and incomplete reference assemblies (particularly for the Y). Here we generated gapless, telomere-to-telomere assemblies of the X and Y chromosomes for all extant great ape species—chimpanzee, bonobo, gorilla, Bornean and Sumatran orangutans—and for an outgroup lesser ape, the siamang. To achieve this, we utilized state-of-the-art experimental and computational methods developed for deciphering the human...
