The red flour beetle T. castaneum: elaborate genetic toolkit and unbiased large scale RNAi screening to study insect biology and evolution

Abstract

The red flour beetle Tribolium castaneum has emerged as an important insect model system for a variety of topics. With respect to studying gene function, it is second only to the vinegar fly D. melanogaster. The RNAi response in T. castaneum is exceptionally strong and systemic, and it appears to target all cell types and processes. Uniquely for emerging model organisms, T. castaneum offers the opportunity of performing time- and cost-efficient large-scale RNAi screening, based on commercially available dsRNAs targeting all genes, which are simply injected into the body cavity. Well established transgenic and genome editing approaches are met by ease of husbandry and a relatively short generation time. Consequently, a number of transgenic tools like UAS/Gal4, Cre/Lox, imaging lines and enhancer trap lines are already available. T. castaneum has been a genetic experimental system for decades and now has become a workhorse for molecular and reverse genetics as well as in vivo imaging. Many aspects of development and general biology are more insect-typical in this beetle compared to D. melanogaster. Thus, studying beetle orthologs of well-described fly genes has allowed macro-evolutionary comparisons in developmental processes such as axis formation, body segmentation, and appendage, head and brain development. Transgenic approaches have opened new ways for in vivo imaging. Moreover, this emerging model system is the first choice for research on processes that are not represented in the fly, or are difficult to study there, e.g. extraembryonic tissues, cryptonephridial organs, stink gland function, or dsRNA-based pesticides.

Discovery of entomopathogenic fungi across geographical regions in southern China on pine sawyer beetle Monochamus alternatus and implication for multi-pathogen vectoring potential of this beetle

“…The other three insecticidal fungal species with no visible parasitism on M. alternatus, namely, A. ruber, P. citrinum, and T. dorotheae, failed re-isolation from artificially infected T. castaneum and also were not observed by SEM. T. castaneum is a Coleopteran model insect widely used in genetic editing, toxicological and immunological research, and active natural product screening (Wang et al, 2007;Klingler and Bucher, 2022), owing to its advantages of short generation-time and simple rearing techniques (Rösner et al, 2020). The consistent results found here further indicate that the laboratory population of T. castaneum could be a good substitute or a tool to evaluate insecticidal activities and infection phenotypes of entomopathogenic fungi for M. alternatus and other Coleopterans.…”

“…T . castaneum is a Coleopteran model insect widely used in genetic editing, toxicological and immunological research, and active natural product screening ( Wang et al., 2007 ; Klingler and Bucher, 2022 ), owing to its advantages of short generation-time and simple rearing techniques ( Rösner et al., 2020 ). The consistent results found here further indicate that the laboratory population of T .…”

Efficienthyperactive piggyBactransgenesis inPlodiapantry moths

“…Both EGFP and EYFP showed robust and strong 3xP3 -driven expression at all generations, without noticeable decrease over time in adult eyes (Das Gupta et al, 2015), with EYFP benefiting from lower autofluorescence effects than EGFP at various stages. We strategically used a white mutant strain deficient for eye-screening pigment, as routinely done in other insects to facilitate the screening of 3xP3 -driven fluorescence (Stern et al, 2017; Klingler and Bucher, 2022), and this mutation also increases the translucency of Plodia larvae (Shirk, 2021; Heryanto et al, 2022). Of note, white mutations can be recessive-lethal in some lepidopteran species (Khan et al, 2017).…”

Efficient hyperactive piggyBac transgenesis in Plodia pantry moths

“…Both EGFP and EYFP showed robust and strong 3xP3-driven expression at all generations, without noticeable decrease over time in adult eyes (Das Gupta et al, 2015), with EYFP benefiting from lower autofluorescence effects than EGFP at various stages. We strategically used a white mutant strain deficient for eyescreening pigment, as routinely done in other insects to facilitate the screening of 3xP3-driven fluorescence (Stern et al, 2017;Klingler and Bucher, 2022), and this mutation also increases the translucency of Plodia larvae (Shirk, 2021;Heryanto et al, 2022). Of note, white mutations can be recessive-lethal in some lepidopteran species (Khan et al, 2017).…”