High-throughput profiling of diapause regulated genes from Trichogramma dendrolimi (Hymenoptera: Trichogrammatidae)

Xue Zhang,Junjie Zhang,Wenmei Du,Zhen Zou,Changchun Ruan

doi:10.1186/s12864-020-07285-4

Xue Zhang, Junjie Zhang + Show 3 more

Open Access

https://doi.org/10.1186/s12864-020-07285-4

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Abstract

BackgroundThe parasitoid wasp, Trichogramma dendrolimi, can enter diapause at the prepupal stage. Thus, diapause is an efficient preservation method during the mass production of T. dendrolimi. Previous studies on diapause have mainly focused on ecological characteristics, so the molecular basis of diapause in T. dendrolimi is unknown. We compared transcriptomes of diapause and non-diapause T. dendrolimi to identify key genes and pathways involved in diapause development.ResultsTranscriptome sequencing was performed on diapause prepupae, pupae after diapause, non-diapause prepupae, and pupae. Analysis yielded a total of 87,022 transcripts with an average length of 1604 bp. By removing redundant sequences and those without significant BLAST hits, a non-redundant dataset was generated, containing 7593 sequences with an average length of 3351 bp. Among them, 5702 genes were differentially expressed. The result of Gene Ontology (GO) enrichment analysis revealed that regulation of transcription, DNA-templated, oxidation-reduction process, and signal transduction were significantly affected. Ten genes were selected for validation using quantitative real-time PCR (qPCR). The changes showed the same trend as between the qPCR and RNA-Seq results. Several genes were identified as involved in diapause, including ribosomal proteins, zinc finger proteins, homeobox proteins, forkhead box proteins, UDP-glucuronosyltransferase, Glutathione-S-transferase, p53, and DNA damage-regulated gene 1 (pdrg1). Genes related to lipid metabolism were also included.ConclusionsWe generated a large amount of transcriptome data from T. dendrolimi, providing a resource for future gene function research. The diapause-related genes identified help reveal the molecular mechanisms of diapause, in T. dendrolimi, and other insect species.

Highlights

The parasitoid wasp, Trichogramma dendrolimi, can enter diapause at the prepupal stage
Termination, sequencing, and gene identification After the completion of the diapause induction process, the parasitized host eggs were dissected to verify whether T. dendrolimi entered diapause successfully
Diapausing parasitoids remain at the prepupal stage (Dpre)

Summary

Introduction

The parasitoid wasp, Trichogramma dendrolimi, can enter diapause at the prepupal stage. Diapause is an efficient preservation method during the mass production of T. dendrolimi. The insect egg parasitoid, Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae), is used as a biological control agent against several important Lepidopteran insect pests, such as Chilo suppressalis [1], Cnaphalocrocis medinalis [2], and Ostrinia furnacalis [3]. Cold storage of parasitized host eggs is the most commonly used method for parasitoid preservation [5]. Trichogramma can be kept for a long period at low temperatures, their performance, such as emergence rate and longevity, decreases as storage time increases. The survival rate of T. dendrolimi significantly decreases after 3 weeks of storage at low temperatures [6], and similar decreases have been found in other Trichogramma species [7, 8]. Diapause can be an effective mechanism to solve this problem

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