Decoding bee cleptoparasitism through comparative transcriptomics of Coelioxoides waltheriae and its host Tetrapedia diversipes

Abstract

Cleptoparasitism, also known as brood parasitism, is a widespread strategy among bee species in which the parasite lays eggs into the nests of the host species. Even though this behavior has significant ecological implications for the dynamics of several species, little is known about the molecular pathways associated with cleptoparasitism. To shed some light on this issue, we used gene expression data to perform a comparative analysis between two solitary neotropical bees: Coelioxoides waltheriae, an obligate parasite, and their specific host Tetrapedia diversipes. We found that ortholog genes involved in signal transduction, sensory perception, learning, and memory formation were differentially expressed between the cleptoparasite and the host. We hypothesize that these genes and their associated molecular pathways are engaged in cleptoparasitism-related processes and, hence, are appealing subjects for further investigation into functional and evolutionary aspects of cleptoparasitism in bees.

Keywords: Brood parasitism; Comparative transcriptomics; Cuckoo bee; Solitary bees.

Figure 1

Relative expression of orthologs differentially expressed between the cleptoparasite Coelioxoides waltheriae and their host Tetrapedia diversipes that were identified as homologs to PiggyBac Transposable Element-derived (1: PGBD2-like; 2: PGBD4-like) and Major Royal Jelly Protein (3) sequences. The respective orthogroups (OGs) are identified according to their IDs in Supplementary Material 3.

Figure 2

Gene Ontology (GO) terms enriched among the Differentially Expressed (DE) Orthologs between Coelioxoides waltheriae and Tetrapedia diversipes. Each pie chart represents one of the three main GO categories: (A) Cellular Component, (B) Molecular Function, and (C) Biological Process. Legends next to each chart indicate the representative color, name, and proportion of DE that received an annotation related to the parental GO term. Child terms from the second hierarchical level are represented in the outermost part of the pie chart using shades of the parental representative term color. Parent–child GO term relationships are listed in Supplementary Material 4.