Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus

Abstract

Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms for developmental, evolutionary, and neurobiological research. Although there has been recent influx of orthopteran transcriptomic resources, many use pooled ontogenetic stages obscuring information about changes in gene expression during development. Here we developed a de novo transcriptome spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus biguttulus. Samples from different stages encompassing embryonic development through adults were used for transcriptomic profiling, revealing patterns of differential gene expression that highlight processes in the different life stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic development showed a strongly differentiated expression pattern compared to all of the other stages and genes upregulated in this stage were involved in signaling, cellular differentiation, and organ development. Our study is one of the first to examine gene expression during post-embryonic development in a hemimetabolous insect and we found that only the fourth and fifth instars had clusters of genes upregulated during these stages. These genes are involved in various processes ranging from synthesis of biogenic amines to chitin binding. These observations indicate that post-embryonic ontogeny is not a continuous process and that some instars are differentiated. Finally, genes upregulated in the imago were generally involved in aging and immunity. Our study highlights the importance of looking at ontogeny as a whole and indicates promising directions for future research in orthopteran development.

Transcriptome assembly for a colour-polymorphic grasshopper (Gomphocerus sibiricus) with a very large genome size

“…This is surprising because the Acridids are the largest family of Orthopterans, comprising around half of all Orthopteran species [10]. The only Acridid transcriptomes published so far are for the desert locust Schistocerca gregaria [11], the migratory locus Locusta migratoria [12], the stripe-winged grasshopper Stenobothrus lineatus [13] and the bow-winged grasshopper Chorthippus biguttulus [14].…”

De novo Assembly of the Burying Beetle Nicrophorus orbicollis (Coleoptera: Silphidae) Transcriptome Across Developmental Stages with Identification of Key Immune Transcripts

“…This current study compares transcriptomes of N. orbicollis , a burying beetle with obligate parental care, that were generated at various stages in the life cycle, including the egg, the larval stages, pupa, and sexually mature (though non-reproducing) adult. Developmental transcriptome profiles are available for non-social model systems with incomplete metamorphosis (i.e., hemimetabolous) such as the cricket Gryllus rubens 22 and acridid grasshopper Chorthippus biguttulus 23 and the subsocial, hemimetabolous European earwig Forficula auricularia 24 ; life-spanning transcriptome analyses are also available for eusocial holometabolous systems, such as the bumblebee Bombus terrestris 4 . In contrast to these studies - and prior works examining Nicrophorus spp.…”

Genome Size Estimation and Full-Length Transcriptome of Sphingonotus tsinlingensis: Genetic Background of a Drought-Adapted Grasshopper

“…Transcriptomics represent an alternative to genomic approaches for non-model organisms ( Yuan et al, 2019 ). Published Acridid transcriptomes include those of Gomphocerus sibiricus ( Shah et al, 2019 ), Locusta migratoria ( Zhang et al, 2018 ), Ceracris nigricornis ( Yuan et al, 2019 ), Chorthippus biguttulus ( Berdan et al, 2017 ), Shirakiacris shirakii ( Qiu et al, 2016 ), and Xenocatantops brachycerus ( Zhao et al, 2018 ). Many available transcripts are associated with growth, development, environmental adaptability, and metabolism of nutrients and bioactive components, including candidate olfactory-related genes, pigmentation, and green pigment metabolism pathways.…”