Genome and Genetic Engineering of the House Cricket (Acheta domesticus): A Resource for Sustainable Agriculture

Abstract

Background: The house cricket, Acheta domesticus, is one of the most farmed insects worldwide and the foundation of an emerging industry using insects as a sustainable food source. Edible insects present a promising alternative for protein production amid a plethora of reports on climate change and biodiversity loss largely driven by agriculture. As with other crops, genetic resources are needed to improve crickets for food and other applications. Methods: We present the first high quality annotated genome assembly of A. domesticus from long read data and scaffolded to chromosome level, providing information needed for genetic manipulation. Results: Gene groups related to immunity were annotated and will be useful for improving value to insect farmers. Metagenome scaffolds in the A. domesticus assembly, including Invertebrate Iridescent Virus 6 (IIV6), were submitted as host-associated sequences. We demonstrate both CRISPR/Cas9-mediated knock-in and knock-out of A. domesticus and discuss implications for the food, pharmaceutical, and other industries. RNAi was demonstrated to disrupt the function of the vermilion eye-color gene producing a useful white-eye biomarker phenotype. Conclusions: We are utilizing these data to develop technologies for downstream commercial applications, including more nutritious and disease-resistant crickets, as well as lines producing valuable bioproducts, such as vaccines and antibiotics.

A long-read draft assembly of the Chinese mantis (Mantodea: Mantidae: Tenodera sinensis) genome reveals patterns of ion channel gain and loss across Arthropoda

“…BUSCO assessment of our annotation showed that a substantial portion of total gene content is likely not represented [odb10_insecta complete = 78.2% (single copy = 75.1%, duplicated = 3.1%), fragmented = 7.9%, missing = 13.9%; Fig. 3 ]; however, this was also the case (albeit less drastically) for our Helixer annotation of A. domesticus [odb10_insecta complete = 86.7% (single copy = 82.7%, duplicated = 4.0%), fragmented = 7.4%, missing = 5.9%; BUSCO complete in assembly = 94.8%; Dossey et al 2023 ] suggesting there may be biases in Helixer's premade invertebrate training data set, which is dominated by insects in the orders Diptera and Lepidoptera (details regarding Helixer training data sets can be found at https://uni-duesseldorf.sciebo.de/s/lQTB7HYISW71Wi0 ). Thus, the lower than expected recovery of single-copy orthologs may represent this bias rather than the quality of our assembly.…”

An Optimized Small-Scale Rearing System to Support Embryonic Microinjection Protocols for Western Corn Rootworm, Diabrotica virgifera virgifera

“…It is geared towards small-scale studies requiring multiple strains or treatments, with the added requirement of having to fit within the confines of an average-sized molecular biology laboratory. This system also allows manipulation of WCR at different life stages, which is necessary when screening for genetic traits such as eye color or fluorescence, which are frequently used as markers when establishing transgenic or knock-out strains [ 21 , 30 , 31 ]. Importantly, it also addresses containment since reducing the risk of WCR escaping the confines of their rearing containers is of vital importance to both maintaining pure breeding strains and ensuring the insects never breach the confines of the laboratory.…”

The genome assembly and annotation of the cricket Gryllus longicercus

“…In terms of contiguousness, the G. longicercus assembly displays the third lowest N90, third highest L90 and the lowest number of total scaffolds. The A. domesticus genome 12 is currently the only publicly available cricket genome assembled at a chromosome level with the 11 chromosomes containing more than the 90% of the genome. After that genome, the genome assembly of G. bimaculatus and the herein presented assembly of G. longicercus are the most complete and contiguous cricket genomes.…”