Abstract:

【Aim】 This study aims to establish the transcriptome database of diapause eggs of Galeruca daurica, to reveal the genes and metabolic/signaling pathways related to egg diapause, and to explore the molecular mechanism of egg diapause at the transcriptomic level. 【Methods】 The Illumina NovaSeq 6000 platform was used to perform transcriptome sequencing and bioinformatics analysis of the diapause and diapause-terminated eggs of G. daurica. The DESeq software was applied to analyze the differentially expressed genes (DEGs) between the diapause and diapause-terminated eggs, and the DEGs were subjected to the KEGG pathway enrichment analysis. The expression profiles of 10 randomly selected DEGs were verified by qRT-PCR. 【Results】 According to the transcriptome sequencing results from the diapause and diapause-terminated eggs of G. daurica, a total of 53 389 unigenes including 2 145 DEGs were obtained, of which 24 DEGs are related to juvenile hormone signaling and fatty acid biosynthesis and degradation. Compared with those in the diapause-terminated eggs, 1 297 DEGs in the transcriptome of diapause eggs were up-regulated and enriched in 124 KEGG pathways, among which ribosome pathway was significantly enriched, and 848 DEGs were down-regulated and enriched in 73 KEGG pathways, among which MAPK signaling pathway and glycosaminoglycan biosynthesis were significantly enriched. The qRT-PCR analysis showed that the expression profiles of the 10 randomly selected DEGs were completely consistent with the RNA-Seq results based on the transcriptome data. 【Conclusion】 Pathways of juvenile hormone, fatty acid biosynthesis and degradation, ribosome, MAPK signaling and glycosaminoglycan biosynthesis may play important roles in the regulation of egg diapause in G. daurica.

Key words: Galeruca daurica, transcriptome, egg diapause, KEGG pathway, juvenile hormone signaling, fatty acid biosynthesis