Identification and expression analysis of microRNAs in worker caste termites of Coptotermes formosanus and Reticulitermes speratus

A total of 114 microRNAs (miRNAs) were identified for Coptotermes formosanus workers, while a total of 97 miRNAs were identified for Reticulitermes speratus workers, of which 91 were common in C. formosanus and R. speratus. While the relationship between miRNA expression levels in C. formosanus and R. speratus workers had a strong positive correlation, considerable difference in miRNA expressions between C. formosanus and R. speratus was observed. Among the miRNAs up-regulated in C. formosanus workers, miR-11-3p showed the highest expression increase of 2.30 fold, while miR-13b-3p showed the highest expression increase of 5.16 fold among the up-regulated miRNAs in R. speratus workers. Workers of C. formosanus and R. speratus seem to use different miRNAs, miR-11-3p in C. formosanus or miR-13b-3p in R. speratus, to regulate homeodomain transcription factor genes, araucan, caupolican, and nubbin, basic helix-loop-helix (bHLH) transcription factor genes, spineless and E(spl)m3-HLH, and zinc finger transcription factor gene, castor.