Transcriptome and population structure of glassy-winged sharpshooters (Homalodisca vitripennis) with varying insecticide resistance in southern California

Abstract

Background Homalodisca vitripennis Germar, the glassy-winged sharpshooter, is an invasive insect in California and a critical threat to agriculture through its transmission of the plant pathogen, Xylella fastidiosa. Quarantine, broad-spectrum insecticides, and biological control have been used for population management of H. vitripennis since its invasion and subsequent proliferation throughout California. Recently wide-spread neonicotinoid resistance has been detected in populations of H. vitripennis in the southern portions of California’s Central Valley. In order to better understand potential mechanisms of H. vitripennis neonicotinoid resistance, we performed RNA sequencing on wild-caught insecticide-resistant and relatively susceptible sharpshooters to profile their transcriptome and population structure. Results We identified 81 differentially expressed genes with higher expression in resistant individuals. The significant largest differentially expressed candidate gene linked to resistance status was a cytochrome P450 gene with similarity to CYP6A9. Furthermore, we observed an over-enrichment of GO terms representing functions supportive of roles in resistance mechanisms (cytochrome P450s, M13 peptidases, and cuticle structural proteins). Finally, we saw no evidence of broad-scale population structure, perhaps due to H. vitripennis' relatively recent introduction to California or due to the relatively small geographic scale investigated here. Conclusions In this work, we characterized the transcriptome of insecticide-resistant and susceptible H. vitripennis and identified candidate genes that may be involved in resistance mechanisms for this species. Future work should seek to build on the transcriptome profiling performed here to confirm the role of the identified genes, particularly the cytochrome P450, in resistance in H. vitripennis. We hope this work helps aid future population management strategies for this and other species with growing insecticide resistance.

Geographical survey of the mycobiome and microbiome of Southern California glassy-winged sharpshooters

“…Other factors might contribute to differences across geographic regions, for example, local environmental conditions (e.g., temperature, humidity, and elevation) or host genetics. Though in GWSS, host genetics may only play a small role as no population structure has been detected in Southern California populations possibly due to their relatively recent introduction ( 33 ). Future studies should incorporate local environmental data, as well as collect possible dietary sources, to help identify the most important factors driving these regional patterns.…”

“…Insecticide resistance usually involves multiple coexisting mechanisms spanning behavioral (e.g., avoidance) and physiological processes (e.g., cuticle modifications and detoxification) ( 23 – 25 ), and studies have proposed a novel role for symbionts and other associated microbes in detoxification of insecticides for their associated hosts ( 26 – 31 ). Recent studies on Southern California GWSS populations have identified both trade-offs in host reproductive fitness associated with resistance ( 32 ) as well as host genes that may play a role in conferring resistance ( 33 ). However, the possible role of the microbiome and mycobiome in the resistance of these GWSS populations has yet to be fully explored.…”

Geographical Survey of the Mycobiome and Microbiome of Southern California Glassy-winged Sharpshooters

“…The imidacloprid-resistance status is known for 53 of these GWSS from assays of these individuals themselves or other individuals from the same collection date or captive line. Imidacloprid status assays were performed as described in Ettinger et al [33]. Insects were stored in RNAlater (ThermoFisher Scientific, Waltham, MA, USA) or 200 proof ethanol and kept at -20°C prior to processing.…”

“…cuticle modifications, detoxification) [23][24][25], and studies have proposed a novel role for symbionts and other associated microbes in detoxification of insecticides for their associated hosts [26][27][28][29][30][31]. Recent studies on Southern California GWSS populations have identified both trade-offs in host reproductive fitness associated with resistance [32] as well as host genes that may play a role in conferring resistance [33]. However, the possible role of the microbiome and mycobiome in the resistance of these GWSS populations has yet to be fully explored.…”

The Critical Biomarkers Identification of Insulin Signaling Involved in Initiating cAMP Signaling Mediated Salivary Secretion in Sjogren Syndrome: Transcriptome Sequencing in NOD Mice Model

“…Transcriptome sequencing is a second-generation sequencing platform to obtain almost quickly and comprehensively all transcripts and gene sequences of a specific cell or tissue of a species in a particular state, which can be used to study gene expression, function, structure, alternative splicing, and new transcript prediction. At present, transcriptome sequencing has been widely used in basic research, clinical diagnosis, and drug discovery [22][23][24][25].…”