show Abstracthide AbstractActinoplanes missouriensis is an actinomycete that forms sporangia containing spores. The sporangia open and release the spores when immersed in water. This process is called sporangium dehiscence. Sporangia of the mutant strain of sipA (AMIS_54230) show the defect in sporangium dehiscence. By contrast, sporangium dehiscence proceeds normally in the double mutant strain of sipA and ssdA (AMIS_54240). The ssdA gene encodes a sigma factor, whereas the sipA gene encodes an anti-sigma factor that inhibits the function of SsdA. Therefore, we compared the transcriptomes of the sipA mutant and sipA/ssdA double mutant strains by RNA-Seq analysis.