Transcriptomic and proteomic analysis of Locusta migratoria eggs at different embryonic stages: Comparison for diapause and non-diapause regimes

Abstract

Temperate-zone insects typically survive winter by entering diapause. Although many aspects of insect diapause have been studied, the underlying molecular mechanism of insect diapause is not well understood. Here we report the results of the transcriptional and translational differences of migratory locust eggs at different embryonic states using diapause (low temperature) and non-diapause (high temperature) regimes. Compared with non-diapause eggs at 100 degree-days (N2) treatment, results indicated that 29 671 transcripts and 296 proteins were differentially expressed at the diapause maintenance stage (D2).While compared with 150 degree-days (N3) treatment, 45 922 transcripts and 404 proteins were differentially expressed in the post-diapause stage (D3). Among them, 51 and 102 transcripts had concurrent transcription and translation profiles in D2 vs. N2 and D3 vs. N3 treatments, respectively. Analysis of Gene Ontology categorized these genes and proteins into three categories: biological processes, cellular components, and molecular functions. Biological pathway analysis indicated that three pathways: (1) insect hormone biosynthesis (KEGG: Map 00981), (2) the insulin signaling pathway (KEGG: Map 04910), and (3) the peroxisome proliferator-activated receptor (PPAR) signaling pathway (KEGG: Map 03320) play an important role in locust diapause regulation. Most of these transcripts and proteins were up-regulated in the diapause treatments, and were highly linked to juvenile hormone biosynthesis, insulin and PPAR signaling pathways, suggesting these three pathways may be involved in diapause and development regulation. This study demonstrates the applicability of high-throughput omics tools to identify biochemical pathways linked to diapause in locust egg development. In addition, it reveals that cellular metabolism in diapause eggs is more inactive than in non-diapause eggs, and most of the down-regulated enzymes and pathways are related to reduce energy loss.

Transcriptomic Analysis Following Artificial Selection for Grasshopper Size

“…The products were purified using a QIAquick PCR extraction kit (Qiagen) and enriched by PCR amplification. The library products were sequenced on an Illumina Hiseq 4000 platform (Illumina, San Diego, CA, USA) and 150 bp paired-end reads were subsequently generated by Novogene Corporation (Novogene, Tianjin, China) as per the protocol [52].…”

Novel Lom-dh Genes Play Potential Role in Promoting Egg Diapause of Locusta migratoria L.

“…A temperature ranging from 27 to 30°C can induce diapause in L. migratoria under short photoperiod. Our previous study also demonstrated that insect hormone biosynthesis, the insulin signaling pathway and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were involved in diapause regulation of the locust eggs (Tu et al, 2015; Hao et al, 2017). Meanwhile, the low level of ecdysteroids in both maternal and offspring eggs was observed in the diapause process, whereas the high quantity of ecdysteroids terminated the diapause in L. migratoria (Tawfik et al, 2002).…”

Serpin7 controls egg diapause of migratory locust (Locusta migratoria) by regulating polyphenol oxidase

“…However, no extensive and comprehensive studies have been made on the effects of serpin in relation with insect diapause. Keeping in view the importance of serpins in other plants and animals, this novel study was designed to carry out the transcriptome analysis of diapause and nondiapause eggs of migratory locust, L. migratoria , especially for the serpin genes [21,22]. We further performed label‐free proteomic sequencing on diapause and nondiapause eggs of migratory locust to understand the expression of serpin‐related genes [21,22].…”

“…Keeping in view the importance of serpins in other plants and animals, this novel study was designed to carry out the transcriptome analysis of diapause and nondiapause eggs of migratory locust, L. migratoria , especially for the serpin genes [21,22]. We further performed label‐free proteomic sequencing on diapause and nondiapause eggs of migratory locust to understand the expression of serpin‐related genes [21,22]. We hypothesized that serpin may affect energy metabolism and could control diapause of migratory locust embryos by regulating protease cascade reaction.…”