ANAT 381 Lecture Notes - Lecture 20: Nucleosome, Transposable Element, Spermatogenesis
Document Summary
We will talk about the inheritance of epigenetic phenomena. Genomic imprinting: stable as development proceeds, so must be inherited through cell. Removal of icr/dmr sequences in adult cells usually does not affect allele-specific. Imprinting is established early in development by having a specific parent of. Effects- may involve transmission to gametes. division. expression. With a dnmt1 mutation of instance: does affect the silencing. So still need dna methylation, but not the icr itself. Maintenance of dna methylation is key for mitotic stability of imprinting. Removal of the xic in adult cells preserves at least some features of the inactive x (reduced expression of some genes is maintained). Can be maintained in the absence of the region required to initiate x inactivation. Xist expression does seem to have a role in maintenance in adults that may be. But there is also xist-independent activation, which can be seen in adults. So distinction between maintenance and initiation mechanisms (where xist is essential).