Cell lines derived from the small hive beetle, Aethina tumida, express insecticide targets

Authors: Corcoran, Jacob; Goodman, Cynthia; Saathoff, Stephen - Steve; Ringbauer, Joseph - Joe; GUO, YA - University Of Florida; BONNING, BRYONY - University Of Florida; Stanley, David

Submitted to: In Vitro Cellular and Developmental Biology - Animal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2021
Publication Date: 11/18/2021
Citation: Corcoran, J., Goodman, C.L., Saathoff, S.G., Ringbauer Jr, J.A., Guo, Y., Bonning, B., Stanley, D.W. 2021. Cell lines derived from the small hive beetle, Aethina tumida, express insecticide targets. In Vitro Cellular and Developmental Biology - Animal. 57:849-855. https://doi.org/10.1007/s11626-021-00633-y.
DOI: https://doi.org/10.1007/s11626-021-00633-y

Interpretive Summary: Small hive beetle (SHB) adults deposit their eggs in honey bee colonies and the larvae feed on honey, pollen and honey bee larvae. These beetles have become a serious challenge to the health and sustainability of honey bee colonies, which contribute over $20 billion per year in pollination services to high-value crops, such as almonds, apples, melons and broccoli. Industrial and academic research to control SHB damage is aimed at developing novel SHB-specific insecticides. The research process involves directly testing hundreds of thousands of chemicals for their ability to kill SHBs while not harming honey bees or other beneficial insects. The classical testing method involves exposing the target pest insect, in this case SHBs, to a chemical and recording the resulting death rates. This is an incredibly inefficient process that requires rearing and maintaining large populations of target pest insects. Modern testing methods rely on establishing cell lines from the target insect and testing the effects of potential insecticides on the cells. The goal of this research is to produce SHB cell lines so they can be used as tools for screening new compounds, in place of live insects. Here we report several cell lines derived from SHB tissues that possess the required characteristics to support insecticide development programs. These SHB cell lines are now available to researchers upon request.

Technical Abstract: The small hive beetle (SHB), Aethina tumida, originated in sub-Saharan Africa and now has a near world-wide distribution. Adult SHBs deposit their eggs in honey bee colonies and the larvae feed on honey, pollen and honey bee larvae. Over time this negatively impacts honey bee populations, which translates into a major economic impact on agriculture. A number of measures have been implemented to control SHBs, including the use of biological agents. Current efforts focus on developing novel, SHB-specific insecticides, which could be enhanced with tools such as cell lines derived from SHB tissues. Here we report on two continuously replicating cell lines derived from SHB eggs and neonate larvae. Each line consists of a variety of cell morphotypes, including firmly attached asymmetrical cells and loosely attached spherical cells. Numerous sublines were then produced from the original two cell lines by limiting dilution to isolate different cell morphotypes, of which nine were selected for further molecular and genetic characterization. DNA barcoding confirmed that these sublines were derived from SHB tissues. Gene expression profiles were evaluated in three sublines via RNA-Seq. The transcriptomic libraries and gene expression profiles allowed for the identification of potential insecticidal targets present in the cell lines. Here we present a small subset of genes expressed in these cell lines that could support insecticide development programs, including members of the ABC-C transporter family; calcium transporters, such as the ryanodine receptor and plasma membrane calcium ATPase; and GPCRs with neurophysiological functions, such as octopamine and pyrokinin receptors.