X chromosome inactivation (XCI) is a process in mammals that ensures equal transcript levels between males and females by genetic inactivation of one of the two X chromosomes in females.
The fusion of muscle cells to form multinuclear myofibers is central to muscle development and has been historically thought to be an irreversible process in mammals.
Interestingly, the preference for ribosome related function also exists in the LSRs of some species: 8%, 13%, and 17% of the LSRs in mouse, rat, and macaca respectively are also ribosome related, indicating that the emergence of ribosome related retrogenes may be a continuing process in mammals.
T-cell lineage differentiation is an ongoing process in mammals with a clear transcription factor "armature" regulation [277] that is currently being thoroughly mapped [275], [278], [279].
Whether any other Zips are involved in this process in mammals is not well-established [ 30].
Caenorhabditis elegans provides a powerful metazoan model for studying DR because it has a short lifespan and is amenable to genetic disruption of processes that might be essential in mammals.
Covalent modification of proteins by SUMO is an essential process in mammals, as evidenced by the embryonic lethality of mouse mutants lacking the SUMO conjugating enzyme, Ubc9 [1].
If this process is conserved in mammals, this would suggest that programmed cell death of phagocytes and subsequent engulfment might serve to resolve neuroinflammation in the brain.
The FOXO/DAF-16 and Nrf2/SKN-1 mediated redox pathways are also reported to be involved in those processes in mammals and the nematode C. elegans (Pi et al., 2007; Putker et al., 2013; Staab et al., 2013).
Animal development from fertilized, totipotent eggs to individuals is an epigenetically programmed process and was believed to be irreversible in mammals.
