Expression patterns of lncRNA5334 and its cis-acting genes in Nosema ceranae

The aim of this study is to reveal the expression pattern and regulatory role of lncRNA5334 during the process of Nosema ceranae infection of Apis mellifera ligustica workers, providing a basis for further investigation of the regulatory mechanism of lncRNA5334.

The expression of lncRNA5334 in Nosema ceranae was verified by RT-PCR. Relevant software were utilized to predict the target genes regulated by lncRNA5334 in cis-acting manner. RT-qPCR was used to detect the relative expression of lncRNA5334 and its target genes during the infestation process.

The results showed that the target fragment of the expected size (approximately 185 bp) was amplified from the N. ceranae spore sample and from the midgut samples of Apis mellifera ligustica workers at 1 dpi (1 day post inoculation), 2 dpi, 3 dpi, and 4 dpi with Nosema ceranae, while no target fragment was detected in the midgut samples of uninoculated workers; as compared with that at 1 dpi, the expression level of lncRNA5334 was downregulated at 2 dpi (P>0.05) and significantly downregulated at 3 dpi and 4 dpi (P< 0.05), presenting an overall trend of continuous decrease in expression; lncRNA5334 potentially regulated the transcription of four up- and down-stream genes (Pol II, Trx, ACS, and GPDH); the expression level of Pol II was up-regulated at 2 dpi and 3 dpi (P>0.05) and significantly up-regulated at 4 dpi (P<0.05), the expression level of Trx was significantly up-regulated at 2 dpi, 3 dpi and 4 dpi (P<0.05), the expression level of ACS was up-regulated at 2 dpi and 4 dpi (P>0.05) and significantly up-regulated at 3 dpi (P<0.05), the expression level of GPDH was down-regulated at 2 dpi (P>0.05) while significantly up-regulated at both 3 dpi and 4 dpi (P<0.05).

These results suggest that lncRNA5334 is expressed in the spore and during the infection process of Nosema ceranae, and lncRNA5334 may potentially modulate the process of Nosema ceranae infection in Apis mellifera ligustica through cis-acting manner through modulating the transcription of Pol II, Trx, ACS, and GPDH.