Why would anthers express so many genes given the relative simplicity of tissues and cell types?
Three histone constitution-related genes were distinctly up-regulated at the tetrad stage in GMS mutant anthers, but exhibited lower expression at the uninucleate microspore stage in GMS mutant anthers (Table 2).
These genes were also distinctly up-regulated at the tetrad stage in GMS mutant anthers, but exhibited lower expression at the uninucleate microspore stage in GMS mutant anthers (Table 2).
For example, three histone constitution-related genes and two methyltransferase genes were differentially expressed in the GMS mutant anthers (Table 2).
Of a total of 34,932 genes that are expressed over the three stages of mutant anthers, 16,145 transcripts were shared across all the three mutant anther stages, 9,737 were stage-specific transcripts and 9,050 genes were expressed at two stages.
More interestingly, five genes involved in ethylene metabolism were differential expressed in WT and GMS mutant anthers.
Both mutant anthers had about 4 times more genes differentially expressed at 1.5 mm than at 1.0 mm; most transcripts are stage-specific confirming the distinctive properties of these two developmental stages [ 20].
In the current study, Gh-miR396 was differentially expressed between 'Dong A' WT and its GMS mutant anthers in the meiosis stage, and it had a higher level of expression in the GMS mutant anthers in the uninucleate microspore stage.
Comparing the expression of these novel miRNAs between WT and GMS mutant anthers, 43, 22 and 56 novel miRNAs were significantly differentially expressed in the meiosis, the tetrad and the uninucleate microspore stages, respectively (Additional file 10).
RNA in situ hybridization revealed that MYB105 as well as MYB101 are expressed in late tapetum [ 86, 87], consistent with our findings of the changes of their expression in the mutant anthers.
