Combined, these results support the conclusion that REST is the primary repressor of its target genes and the roles of Polycomb and the H3K27me3 mark are functionally dispensable for its activity.
Due to these redundant binding modes, the PAM2 motif of GW182 is functionally dispensable for PABP binding and silencing in D. melanogaster (Eulalio et al., 2009; Huntzinger et al., 2010).
In contrast to the midbrain, Gata2 is not expressed in the anterior forebrain GABAergic precursors (Parras et al., 2002; Petryniak et al., 2007), and while it is expressed in the r1 it is functionally dispensable for GABAergic neurogenesis, possibly because of co-expression of Gata3 (Kala et al., 2009; Achim et al., 2012).
Such genes may be functionally dispensable and redundant to some degree.
The DNA2/FEN1 pathway might therefore be functionally dispensable and may be a minor pathway in the human mitochondrial replication system.
We also identified six genes from the Human Kinase Panel which, in contrast to the above functionally important genes, have been shown to be functionally dispensable in oocytes.
For instance in the case of IRE1 (Inositol-requiring enzyme 1), its phosphoryl transfer activity is functionally dispensable [ 46].
However, it lacks C-terminal extension region of Pam16 which is functionally dispensable in yeast (32).
Thus, the absence of grn1 and grn2 expression prior to the onset of zygotic expression argues that these genes are functionally dispensable in early embryogenesis.
Positive control normalized data from both assays are presented for all genes in the GX Human Kinase Panel in Supplemental Tables 1 and 2. As described in greater detail later, this paper focused on a subset of ten genes extracted from the Kinase Panel that were previously shown to be functionally important specifically within the context of oocytes and seven functionally dispensable genes.
