A chromatin link to caste identity in the carpenter ant Camponotus floridanus
- Daniel F. Simola1,9,
- Chaoyang Ye1,7,9,
- Navdeep S. Mutti2,8,
- Kelly Dolezal2,
- Roberto Bonasio3,4,
- Jürgen Liebig2,10,
- Danny Reinberg3,4,10 and
- Shelley L. Berger1,5,6,10
- 1Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA;
- 2School of Life Sciences, Arizona State University, Tempe, Arizona 85287, USA;
- 3Department of Biochemistry, New York University School of Medicine, New York, New York 10016, USA;
- 4Howard Hughes Medical Institute, New York University School of Medicine, New York, New York 10016, USA;
- 5Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA;
- 6Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104, USA
-
↵9 These authors contributed equally to this work.
Abstract
In many ant species, sibling larvae follow alternative ontogenetic trajectories that generate striking variation in morphology and behavior among adults. These organism-level outcomes are often determined by environmental rather than genetic factors. Therefore, epigenetic mechanisms may mediate the expression of adult polyphenisms. We produced the first genome-wide maps of chromatin structure in a eusocial insect and found that gene-proximal changes in histone modifications, notably H3K27 acetylation, discriminate two female worker and male castes in Camponotus floridanus ants and partially explain differential gene expression between castes. Genes showing coordinated changes in H3K27ac and RNA implicate muscle development, neuronal regulation, and sensory responses in modulating caste identity. Binding sites of the acetyltransferase CBP harbor the greatest caste variation in H3K27ac, are enriched with motifs for conserved transcription factors, and show evolutionary expansion near developmental and neuronal genes. These results suggest that environmental effects on caste identity may be mediated by differential recruitment of CBP to chromatin. We propose that epigenetic mechanisms that modify chromatin structure may help orchestrate the generation and maintenance of polyphenic caste morphology and social behavior in ants.
Footnotes
-
↵8 DuPont Agricultural Biotechnology, Wilmington, DE 19880, USA.
-
↵10 Corresponding authors
E-mail bergers{at}mail.med.upenn.edu
E-mail danny.reinberg{at}nyumc.org
E-mail juergen.liebig{at}asu.edu
-
[Supplemental material is available for this article.]
-
Article published online before print. Article, supplemental material, and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.148361.112.
- Received August 22, 2012.
- Accepted November 21, 2012.
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genome.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 3.0 Unported License), as described at http://creativecommons.org/licenses/by-nc/3.0/.
