Roots of N-deficient plants treated with nitrogen sources exhibits divergent expression level of DUR3 orthologs: in rice, OsDUR3 is weakly induced after 3 hours of treatments with 1 mM urea [ 19], in Arabidopsis, 1 mM urea represses AtDUR3 expression at 3 and 6 hours and induced it at 9 and 24 hours [ 18].
We looked for other examples of differential gene expression by considering EST counts in deeply sequenced cDNA libraries, and found that a significant fraction (about one third to one half-) of duplicate genes show divergent expression levels in specific tissues.
Both in our study and in that in Arabidopsis by [ 13], a higher proportion of nonadditive expression occurred in hybrids whose parents showed divergent expression levels than in hybrids whose parents had similar expression levels.
We compared 40 SAGE-derived transcripts with the most divergent expression levels between ROP- Os/+ versus C57- Os/+ kidneys, with the human microarray expression data, comprised of samples obtained from micro-dissected human kidney biopsies from patients with FSGS [ 40].
Additionally, divergent expression levels during meiosis are observed between full-length LTR retrotransposons and solitary LTR sequences.
On the other hand, expression levels of "Divergent M -L-LTVA"- and R-superfaM -L-LTVAd A-like group in C. tribblei and C. lenavati were M -L-LTVAr (10 < FPKM < 100).
An explanation for these apparently divergent conclusions could be the fact that expression levels of cyclooxygenase-1 and -2, as the main targets of NSAIDs, are dependent on the stage of AD pathology [ 82].
The relative expression levels of these genes are even more divergent if calculated using arbitrarily selected reference genes (for example, Act5C, data not shown).
Indeed, expression levels of the majority of genes displaying divergent promoters were found to be above the 3rd quartile of expression value distribution in ΔRag thymocytes.
Expression of the adjacent divergent At5g03150 was also tested to make sure that the expression levels of this gene were not affected in the At3g03160 insertion line.
