Title: | The transcription factor Kruppel homolog 1 is linked to hormone mediated social organization in bees |
Author(s): | Shpigler H; Patch HM; Cohen M; Fan Y; Grozinger CM; Bloch G; |
Address: | "Department of Evolution, Systematics, and Ecology, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel" |
ISSN/ISBN: | 1471-2148 (Electronic) 1471-2148 (Linking) |
Abstract: | "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, Kruppel-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" |
Keywords: | Animals Bees/genetics/*physiology Brain/metabolism Insect Proteins/*metabolism Juvenile Hormones/*metabolism Kruppel-Like Transcription Factors/*metabolism Molecular Sequence Data Social Behavior; |
Notes: | "MedlineShpigler, Hagai Patch, Harland M Cohen, Mira Fan, Yongliang Grozinger, Christina M Bloch, Guy eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. England 2010/05/01 BMC Evol Biol. 2010 Apr 30; 10:120. doi: 10.1186/1471-2148-10-120" |