Comparison of gene expression in the red imported fire ant (Solenopsis invicta) under different temperature conditions

Abstract

The red imported fire ant (RIFA), Solenopsis invicta Buren is native to South America and is known as a global problematic invasive species. This study focused on the molecular response of RIFA by comparing gene expression profiles after exposing ants to low (10 °C) and high (40 °C) temperature stress and comparing them to untreated controls (30 °C). A total of 99,085 unigenes (the clustered non-redundant transcripts that are filtered from the longest assembled contigs) were obtained, of which 19,154 were annotated with gene descriptions, gene ontology terms, and metabolic pathways. 86 gene ontology (GO) functional sub-groups and 23 EggNOG terms resulted. Differentially expressed genes (DEGs) with log2FC ≥ 10 were screened and were compared at different temperatures. We found 203, 48, and 66 specific DEGs co-regulated at 10, 20, and 40 °C. Comparing transcriptome profiles for differential gene expression resulted in various DE genes, including cytochrome P450, NADH dehydrogenase subunit 1, cuticle protein and heat shock protein (HSP), which have previously been reported to be involved in cold and high temperature resistance. GO analysis revealed that antioxidant activity is up-regulated under high temperature stress. We verified the RNA-seq data by qPCR on 20 up- and down-regulated DEGs. These findings provide a basis for future understanding of the adaptation mechanisms of RIFA and the molecular mechanisms underlying the response to low and high temperatures.

Comparative RNA-Seq Analyses of Solenopsis japonica (Hymenoptera: Formicidae) Reveal Gene in Response to Cold Stress

“…The CYP family is also a superfamily associated with oxidative metabolism. It has been previously reported that CYP is related to temperature regulation [44,59]. In the present study, several genes encoding CYP (10 mRNAs) were also found to be significantly up-regulated under cold stress.…”

“…HSP, as a highly conserved molecular chaperone, plays an important role in organism responses to stressor conditions, such as cold hardiness, that can have an effect on the folding and functional conformation of proteins [28,60]. Compared with previous studies that proved HSP genes can be induced to express by cold and heat stress [44,60], we could not find many HSPs. We found just two HSPs (Table S8) that were down-regulated by cold stress at 9 • C for 24 h. There is a report that many HSP genes are differentially expressed under the cold (9 • C for 24 h) in ladybirds [21].…”

“…Significant unigene results were analyzed as up-and down-regulated count by log2FC ≥ 1 and ≤−1. The distribution of expression levels between the two groups was plotted as a Volcano plot and simple bar plots [44].…”

Differential Transcriptome Analysis Reveals Genes Related to Low- and High-Temperature Stress in the Fall Armyworm, Spodoptera frugiperda

“…A gene called EF1α was employed as a reference gene to standardize the expression levels of target genes under various treatments ( Shu et al, 2021 ). Finally, the data was compared based on the fold change (FC) ratio and the mRNA expression level ratio for all identified genes ( Vatanparast et al, 2021 ).…”

Glycerol biosynthesis plays an essential role in mediating cold tolerance the red imported fire ant, Solenopsis invicta

“…Talcum powder was dusted on the top 10 cm interior edge of the trays and along the bottom of the larger holding trays so that any ants escaping would be trapped inside the holding trays. Ants were fed a 20% sucrose solution, mealworms ( Tenebrio molitor larvae), and a described artificial diet (Dussutour & Simpson, 2008; Vatanparast et al, 2021).…”