Genomics of Odonates and Genetics of Colour Polymorphisms
Polymorphisms are widespread in nature and among the most famous examples is the light and melanistic peppered moth (Biston betularia) in England. However, the genetics behind such polymorphisms have been identified in only a limited number of cases, and we therefore lack a general understanding of the evolutionary processes that influence the evolution and maintenance of different morphs within a species. The blue-tailed damselfly Ischnura elegans (Odonata) has an interesting female colour polymorphism with one androchrome, male-mimicking morph, and two female-specific morphs. The polymorphism has a simple one-locus, two allele inheritance. The Ischnura linkage mapping project aims at revealing the genetics of this colour polymorphism.
We will produce the first linkage map for an Odonate species to get insights into the genetic architecture of the colour polymorphism in I. elegans, as well as open new possibilities for comparative genomic research. Until now, studies on the polymorphism in I. elegans can only use the trimorphic adult females as natural genetic markers, and a thorough understanding of the realised life-time consequences of this polymorphism can not be gained, unless a genetic marker is developed.
Access to genome-wide distributed SNPs in I. elegans will allow a host ecological questions to be answered. For instance, we hope to gain a better understanding of the degree of differential introgression in the genome of I. elegans in the zone of sympatry with its sister species I. graellsii in Spain. By screening several Ischnura populations with different hybridization history on a large set of mapped markers, we will be able to quantify the genomic pattern of introgression in a similar way as done in the classical study on Helianthus sunflowers (Rieseberg et al. 1996, Science 272: 741-745). Non-introgressed chromosome regions are candidates for ‘speciation islands’ with an accumulation of key speciation genes.
Key publications: * Wellenreuther M, Sánchez-Guillén RA, Cordero-Rivera A, Svensson EI, Hansson B (2011) Environmental and Climatic Determinants of Molecular Diversity and Genetic Population Structure in a Coenagrionid Damselfly. PLoS ONE 6(6): e20440. doi:10.1371/journal.pone.0020440 * Sánchez-Guillén RA, Wellenreuther M, Cordero-Rivera A, Hansson B (2011) Introgression and rapid species turnover in sympatric damselflies. BMC Evolutionary Biology 11:210. doi:10.1186/1471-2148-11-210 * Sanchez-Guillen, R. A., Hammers, M., Hansson, B., & Van Gossum, H. (2013). Ontogenetic shifts in male mating preference and morph-specific polyandry in a female colour polymorphic insect. BMC Evolutionary Biology. Biomed Central Ltd. * Wellenreuther, M., Sánchez-Guillén, R. A., Cordero-Rivera, A., Svensson, E. & Hansson B. (2013). Male-biased recombination in odonates: insights from a linkage map of the damselfly Ischnura elegans. Journal of Genetics. Springer.
Prof Bengt Hansson Dept of Biology Lund University Ecology Building, 22362 Lund, Sweden Phone: +46-(0)709-916896 Email: bengt.hansson(at)biol.lu.se Skype: skype.bengt.hansson