In summary, our new results suggest that genes acting in a biological process (FA biosynthesis) can be indicated by their presence in the same coexpression network cluster, but genes involved in the same pathway (TAG assembly) may not necessarily exhibit expression coherence.
The major challenges are: (1) Genes involved in a pathway may exhibit complex expression relationships beyond co-expression, which may be overlooked by standard microarray analysis methods such as clustering [ 5]. (2) Pathways are dynamic and the current static annotation of pathways may not serve as a good template.
Second, genes that may exhibit differential expression in more than one study may not reach differential expression when all the data across studies is considered, because the variation across studies is greater than the variation within study.
We speculate that certain genes with mild PO expression biases in TSCs, such as the CIG Qk, may not be imprinted in the canonical sense, but may exhibit imprinted expression due to their proximity to strongly imprinted controlling elements that are able to impose a PO expression bias on nearby susceptible genes.
The pair of genes selected may exhibit compensatory expression, such that one reference gene that is slightly over-expressed and one that is slightly over-expressed in the same group of samples are recommended as the reference genes.
Some ancillary subunits may exhibit varied expression to shape spatial Kv current variation, for example, KChIP2 and the epicardial-endocardial Ito current density gradient.
However, it is possible that some of these genes may exhibit altered expression several hours after encountering a female, or after repeated exposure to a female.
miRNA may exhibit different expression levels between normal and cancer cells [ 33].
Taken together, these results suggest that the housekeeping genes are regulated differently in different plant species and may exhibit differential expression patterns.
