The transcriptomic changes associated with the development of social parasitism in the honeybee Apis mellifera capensis

Abstract

Social insects are characterized by the division of labor. Queens usually dominate reproduction, whereas workers fulfill non-reproductive age-dependent tasks to maintain the colony. Although workers are typically sterile, they can activate their ovaries to produce their own offspring. In the extreme, worker reproduction can turn into social parasitism as in Apis mellifera capensis. These intraspecific parasites occupy a host colony, kill the resident queen, and take over the reproductive monopoly. Because they exhibit a queenlike behavior and are also treated like queens by the fellow workers, they are so-called pseudoqueens. Here, we compare the development of parasitic pseudoqueens and social workers at different time points using fat body transcriptome data. Two complementary analysis methods-a principal component analysis and a time course analysis-led to the identification of a core set of genes involved in the transition from a social worker into a highly fecund parasitic pseudoqueen. Comparing our results on pseudoqueens with gene expression data of honeybee queens revealed many similarities. In addition, there was a set of specific transcriptomic changes in the parasitic pseudoqueens that differed from both, queens and social workers, which may be typical for the development of the social parasitism in A. m. capensis.

Transcriptomic signatures of ageing vary in solitary and social forms of an orchid bee

“…Interestingly, a similar gene expression pattern has been found in honeybees, in which genes linked to oxido-reductase activity were upregulated with age in workers (Aumer et al 2018); in the ant Temnothorax rugatulus, where the oxidation-reduction process was the only significantly enriched GO term for genes downregulated with age in queen brains (Negroni, Foitzik, and Feldmeyer 2019); and in the termite Cryptotermes secundus, where multiple transcripts related to oxidative stress were upregulated in young compared to old queens and kings. Workers showed the opposite trend, with such transcripts being upregulated in older individuals (Kuhn, Meusemann, and Korb 2019).…”

A Single SNP Turns a Social Honey Bee (Apis mellifera) Worker into a Selfish Parasite

“…To test whether transcription patterns of mycC , Th , and Ethr show an association with the mode of parthenogenesis, we utilized previously established fat body transcriptome data (Aumer et al. 2018) and compared the gene expression between thelytokous A. m. capensis pseudoqueens (social parasitic lineage in NE South Africa) and arrhenotokous A. m. scutellata workers (NE South Africa), both sampled at four consecutive time points (3, 4, 7, and 8 days after emergence).…”

“…2011). After 8 days, all experimental A. m. capensis workers had fully activated ovaries, but the experimental A. m. scutellata workers were characterized by low levels of ovary development at all sampling time points (Aumer et al. 2018).…”

“…To assess transcript abundance dynamics of Th , mycC , and Ethr in thelytokous and arrhenotokous workers, we used previously published fat body RNAseq data (NCBI SRA accession: SRP135683; Aumer et al. 2018) from A. m. capensis workers of the socially parasitic lineage (thelytokous, obtained from infested A. m. scutellata colonies in NE South Africa) and A. m. scutellata workers (arrhenotokous, obtained from queenright A. m. scutellata colonies in NE South Africa).…”

“…Adapters were trimmed using Trimmomatic (Bolger et al. 2014) (v0.36) and all libraries (65,900,726 ± 6,190,602 [SD] reads per library [Aumer et al. 2018]) were aligned to the honeybee reference scaffold assembly Amel_4.5 (Elsik et al.…”