Creating transgenic insects is a key technology in insect genetics and molecular biology. A widely used instrument in insect transgenesis is the piggyBac transposase, resulting in essentially ran-dom genomic integrations. In contrast, site-specific recombinases allow the targeted integration of the transgene construct into a specific genomic target site. Both strategies, however, often face limitations due to low transgenesis rates. We aimed to enhance transgenesis rates by utilizing a capped mRNA as a source of transposase or recombinase instead of a helper plasmid. A system-atic comparison of transgenesis rates in Aedes mosquitoes, as models for hard to transform in-sects, showed that suppling piggyBac transposase as mRNA increased the average transfor-mation efficiency in Aedes aegypti from less than 5% with the plasmid source to about 50% with mRNA. Similar high transformation activity was observed in Ae. albopictus with pBac mRNA. No efficiency differences between plasmid and mRNA were observed in recombination experi-ments. Furthermore, a codon-optimized version of piggyBac transposase delivered as plasmid didn’t improve the transformation efficiency in Ae. aegypti or the agricultural pest D. suzukii. We believe that the use of mRNA has strong potential for enhancing pBac transformation efficiencies in other mosquitoes and important agricultural pests such as tephritids.

The complex color patterns on the wings and body of Drosophila guttifera (D. guttifera) are emerging as model systems for studying evolutionary and developmental processes. Studies regarding these processes depend on overexpression and down-regulation of developmental genes, which ultimately rely upon an effective transgenic system. Methods describing transgenesis in Drosophila melanogaster (D. melanogaster) have been extensively reported in several studies. However, these methods cannot be directly applied to D. guttifera due to the low egg production rate and very delicate embryos’ pre-injection treatment requirements. In this protocol, we describe extensively a comprehensive method used for generating transgenic D. guttifera. Using the protocol described here, we are able to establish transgenic lines, identifiable by the expression of Enhanced Green Fluorescent Protein (EGFP) in the eye disks of D. guttifera larvae. The entire procedure, from injection to screening for transgenic larvae, can be completed in approximately 30 days and should be relatively easy to adapt to other non-model Drosophila species, for which no white-eyed mutants exist.

Molluscan aquaculture is a major contributor to global seafood production, but is hampered by infectious disease outbreaks which can cause serious economic losses. Selective breeding has been widely used to improve disease resistance in major agricultural and aquaculture species, and has clear potential in molluscs, albeit its commercial application remains at a formative stage. Advances in genomic technologies, especially development of cost-efficient genomic selection, have potential to accelerate genetic improvement. However, tailored approaches are required due to the distinctive reproductive and lifecycle characteristics of molluscan species. Transgenesis and genome editing, in particular CRISPR/Cas systems, have been successfully trialled in molluscs, and may further understanding and improvement of genetic resistance to disease through targeted changes to the host genome. Whole organism genome editing is achievable on a much greater scale compared to other farmed species, making genome-wide CRISPR screening approaches plausible. This review discusses the current state and future potential of selective breeding, genomic tools, and genome editing approaches to understand and improve host resistance to infectious disease in molluscs.

Sperm marking represents a valuable monitoring tool for genetic pest control strategies such as the Sterile Insect Technique, but also provides a key tool for reproductive biology studies. Sperm-marked lines can be generated by introducing transgenes that mediate the expression of fluorescent proteins during spermatogenesis. Homozygous lines established by transgenesis approaches are going through a genetic bottleneck that can lead to reduced fitness. Transgenic SIT approaches have mostly focused on Dipteran and Lepidopteran pests so far. With this study, we provide sperm-marked lines for the Coleopteran pest model organism, the red flour beetle Tribolium castaneum, based on the β2-tubulin promoter/enhancer driving red (DsRed) or green (EGFP) fluorescence. The obtained lines are reasonably competitive and were thus used for studies on reproductive biology confriming the phenomenon of ‘last male sperm precedence’ and that the spermathecae are deployed for long term sperm storage enabling the use of sperm from first matings even after secondary matings for a long period of time. The homozygosity and competiveness of the lines will enable future studies to analyze the controlled process of sperm movement into the long time storage organ as part of a post-mating cryptic female choice mechanism of this extremely promiscuous species.

Plants are exposed to a variety of abiotic and biotic stresses leading to increased formation of reactive oxygen species (ROS) in plant cells. ROS are capable of oxidizing proteins, pigments, lipids, nucleic acids, and other cell molecules, disrupting their functional activity. During the process of evolution, numerous antioxidant systems were formed in plants, including antioxidant enzymes and low-molecular-weight non-enzymatic antioxidants. Antioxidant systems perform neutralization of ROS and therefore prevent oxidative damage of cell components. In the present review, we focus on the biosynthesis of non-enzymatic antioxidants in higher plant cells such as ascorbic acid (vitamin C), glutathione, flavonoids, isoprenoids, including carotenoids, tocopherol (vitamin E), ubiquinone and plastoquinone. Their functioning and their reactivity with respect to individual ROS are described. The review is also devoted to the modern genetic engineering methods, which are widely used to change the quantitative and qualitative content of the non-enzymatic antioxidants in cultivated plants. These methods allow to obtain various plant lines with given properties in a rather short time. The most successful approaches for plant transgenesis and plant genome editing for the enhancement of the biosynthesis and the content of these antioxidants are discussed.