The transcription factor Krüppel homolog 1 is linked to hormone mediated social organization in bees

Hagai Shpigler*, Harland M. Patch, Mira Cohen, Yongliang Fan, Christina M. Grozinger, Guy Bloch

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Background. Regulation of worker behavior by dominant queens or workers is a hallmark of insect societies, but the underlying molecular mechanisms and their evolutionary conservation are not well understood. Honey bee and bumble bee colonies consist of a single reproductive queen and facultatively sterile workers. The queens' influences on the workers are mediated largely via inhibition of juvenile hormone titers, which affect division of labor in honey bees and worker reproduction in bumble bees. Studies in honey bees identified a transcription factor, Krüppel-homolog 1 (Kr-h1), whose expression in worker brains is significantly downregulated in the presence of a queen or queen pheromone and higher in forager bees, making this gene an ideal candidate for examining the evolutionary conservation of socially regulated pathways in Hymenoptera. Results. In contrast to honey bees, bumble bees foragers do not have higher Kr-h1 levels relative to nurses: in one of three colonies levels were similar in nurses and foragers, and in two colonies levels were higher in nurses. Similarly to honey bees, brain Kr-h1 levels were significantly downregulated in the presence versus absence of a queen. Furthermore, in small queenless groups, Kr-h1 levels were downregulated in subordinate workers with undeveloped ovaries relative to dominant individuals with active ovaries. Brain Kr-h1 levels were upregulated by juvenile hormone treatment relative to a vehicle control. Finally, phylogenetic analysis indicates that KR-H1 orthologs are presence across insect orders. Though this protein is highly conserved between honey bees and bumble bees, there are significant differences between orthologs of insects from different orders. Conclusions. Our results suggest that Kr-h1 is associated with juvenile hormone mediated regulation of reproduction in bumble bees. The expression of this transcription factor is inhibited by the queen and associated with endocrine mediated regulation of social organization in two species of bees. Thus, KR-H1 may transcriptionally regulate a conserved genetic module that is part of a pathway that has been co-opted to function in social behavior, and adjusts the behavior of workers to their social environmental context.

Original languageAmerican English
Article number120
JournalBMC Evolutionary Biology
Issue number1
StatePublished - 2010

Bibliographical note

Funding Information:
The authors would like to thank Noa Kahana and Michal Merling for assistance with the bees. We thank members of the Grozinger laboratory for helpful discussions and critical reading of the manuscript. This work was supported by an NSF CAREER grant (0746338) and by funding from North Carolina State University to CMG, grants from the US-Israel Binational Science Foundation (BSF, #2007465), and Israel Science Foundation (ISF, #452/07) to GB, and a "Hoffman Leadership and Responsibility" fellowship to HS.


Dive into the research topics of 'The transcription factor Krüppel homolog 1 is linked to hormone mediated social organization in bees'. Together they form a unique fingerprint.

Cite this