John H. Werren
Nathaniel & Helen Wisch Professor of Biology
University of Rochester
Department of Biology
River Campus Box 270211
Rochester, New York 14627-0211
Hutchison 306 (office)
Hutchison 309 (lab)
(585) 275-3694 (office)
(585) 275-3889 (lab)
Dr. Werren's area of interest is evolutionary genetics. His research combines genetic, molecular, and population studies to investigate a variety of topics in evolution. Current research topics include: (1) evolution of inherited microorganisms, (2) genetic basis of morphological and behavioral differences between species, (3) genetic conflict and the evolution of "parasitic" or "selfish" DNA, and (4) function and evolution of parasitoid venoms.
Wolbachia are a widespread and common group of cytoplasmically inherited bacteria that cause reproductive incompatibility, parthenogenesis and feminization in their hosts. Studies are underway to investigate genome co-evolution of Wolbachia and their hosts, distribution and movement of Wolbachia in global and local insect communities, and mechanisms of action of Wolbachia. Key questions concern how these bacteria move between host species and whether they promote speciation in invertebrates. This work is part of a five-year multi-institutional NSF grant to investigate evolutionary and ecological genetics of Wolbachia. Dr Werren is the PI and coordinator of this grant.
Nasonia consist of a complex of three closely related species. Research efforts are geared towards investigating the genetic basis of morphological, behavioral, and developmental differences between the species. The ultimate goal is to identify the genes involved in species differences and speciation. The haplodiploid genetics of Nasonia make this complex of species particularly suited for genetic studies of speciation and species differences. We are currently using Nasonia to study the genetic basis of wing size differences. Male wing size differs by 2.5 fold between the species, with small vestigial wings having evolved in one species. The differences are due primarily to differences in cell size. Female wing sizes are similar in the three species. Therefore, this represents the neo-evolution of a sex specific and tissue specific regulation of cell size. Our genetic analysis reveals a few loci of major effect are responsible for the species difference. In Nasonia we can readily introgress genes from one species into the genetic background of another. This approach is being used for fine-scale genetic analysis and positional cloning of wing genes. The goal is to determine the genetic (e.g. sequence) and developmental changes associated with wing size, and the adaptive significance of this trait.
The three Nasonia species also differ in male courtship and female mate preferences. Using similar approaches to those above, we have introgressed loci affecting mate preferences between the species and are using these to investigate the genetic and behavioral underpinnings of mate choice and to test sexual selection theories.
Genetic conflict is an inherent feature of sex determining systems. For example, conflicting selective pressures occur between cytoplasmically and chromosomally inherited genes, and between maternal effect and zygotic sex determining loci. We are combining theoretical and empirical approaches to investigate the genetic basis of sex determination and the role of genetic conflict in sex determination evolution.
Please visit the research lab web site for more information.
Selected Publications (191 Total)
SELECTED PUBLICATIONS (191 Total)
- (2013). Function and Evolution of DNA Methylation in Nasonia vitripennis. PLoS Genetics 9(10) :e1003872. doi:10.1371/journal.pgen.1003872
- (2013). Cuticular hydrocarbon divergence in the jewel wasp Nasonia: Evolutionary shifts in chemical communication channels? J. Evol. Biol. DOI: 10.1111/jeb.12242. NIHMSID 518856.
- (2013). Characterization of an ancient lepidopteran lateral gene transfer. PLoS One 8:1-9. e5926210.1371/journal.pone.0059262. PMID: 23533610
- (2013). Fine-scale mapping of the Nasonia genome to chromosomes using a high-density genotyping microarray. G3: Genes, Genomes and Genetics 3:205-215. PMID:23390597
- (2012). High-throughput olfactory conditioning and memory retention test reveal variation in Nasonia parasitic wasps. Genes, Brain & Behavior 11:879-887. PMID:2280496
- (2012). Commentary: Symbionts provide pesticide detoxification. PNAS 109 (22), 8364-8365. doi/10.1073/pnas.1206194109. PMID:22615369
- (2012). Evolution of shape by multiple regulatory changes to a growth gene. Science 335:943-947. DOI: 10.1126/science.1215193. PMC3520604
- (2011) . Host genotype changes bi-directional to uni-directional cytoplasmic incompatibility in Nasonia longicornis. Heredity 08:105-114 . doi: 10.1038/hdy.2011.53. PMID:21792226.
- (2011). Selfish Genetic Elements, Genetic Conflict, and Evolutionary Innovation. Proc. Natl. Acad. Sci. 108:10863-10870 . PMID:2169039.
- 2010. Using the Wolbachia bacterial symbiont to teach inquiry-based science: A high school laboratory series. American Biology Teacher 72:478-483 .
- 2010. Non-coding Changes Cause Sex-specific Wing Size Differences Between Closely Related Species of Nasonia. PLOS Genetics 6(1) :e1000821 ; doi:10.1371/journal.pgen.1000821.
- 2010. Functional and evolutionary insights from the genomes of three parasitoid Nasonia species. Science 327:343-348.
- 2010. Evolution of sex-specific wing shape at the widerwing locus in four species of Nasonia. Heredity 104:260-269 ; doi:10.1038/hdy.2009.146.
- 2010. Insights into the venom composition of the ectoparasitoid wasp Nasonia vitripennis from bioinformatic and proteomic studies. Insect Mol. Biol. 19(S1) :11-26 .
- 2009. The Parasitoid Wasp Nasonia: An Emerging Model System With Haploid Male Genetics. Cold Spring Harbor Protocols doi:10.1101/pdb.emo134. PMID:20147035. PMC2916733
- 2009. Life and death of an influential passenger: Wolbachia and the evolution of CI-modifiers by their hosts. Plos One 4 (2) :e4425.
- 2008 Wolbachia: Master Manipulators of Invertebrate Biology. Nature Reviews Microbiology 6:741-751.
- 2007. Widespread Lateral Gene Transfers from Intracellular Bacteria to Multicellular Eukaryotes. Science 317 (5845):1753-1756.