Analysis of Gene Expression Changes in Response to Field-to-Lab Transition in the Argentine Ant, Linepithema humile

Gene expression research is a valuable tool for investigating how gene regulation and expression control the underlying behaviors that structure a eusocial insect colony. However, labs that focus on ant research frequently keep ant colonies in the lab for ease of sampling. These laboratories typically do not attempt to completely emulate the ant's natural environment, and thus can expose the colonies to drastically different environmental conditions and food sources than they are used to in the wild. These shifts in diet and environment can cause changes in gene expression of the ants, affecting downstream behavioral and physiological systems. To examine the nature of these changes, colonies of the Argentine ant, Linepithema humile, (Mayr, 1868), were excavated from North Carolina and transferred to the lab, where they are sampled monthly. Illumina and qPCR analyses were conducted on forager samples to detect any changes in gene expression. Approximately six percent of the Argentine ant genome showed changes in gene regulation after six months in the laboratory environment. The subset of these genes examined via qPCR show that the expression of many genes are correlated with each other, indicating that these genes might be a part of a regulatory network. These findings showed that ant colonies kept in the lab experience changes in gene expression, resulting in downstream effects. Therefore, lab ant colonies are not necessarily representative of wild colonies when conducting experiments on the gene expression, behavior, and physiology of these colonies.