Signal and Response Coevolution - Specific Projects

• Identifying the level and importance of sexual communication variation
  in the two host strains of Spodoptera frugiperda

PhD project Melanie Marr (Funded partly by DFG)

The fall armyworm Spodoptera frugiperda (J. E. Smith) consists of two different strains, a so-called "corn" strain that is primarily found in corn fields, and a "rice" strain that is found in rice fields and in pastures of various grasses. These two sympatrically occurring strains are morphologically indistinguishable from each other but they exhibit genetic and behavioral differences (e.g. differential host plant choice, behavioral isolation through different mating times in scotophase). more >>>

Collaborators: Manfred Ayasse, Carlos Blanco, David Jenkins, María Laura Juárez, Juan Lopez, Jeremy McNeil, Rob Meagher, Silvia Schmidt, Gerhard Schöfl

• Silencing candidate genes (fatty acyl reductase and delta-11-desaturase)
  in the pheromone biosynthetic pathway

Diploma (~MSc) project David Neunemann

In Heliothis virescens (Hv) a number of candidate genes involved in pheromone synthesis were identified (Vogel et al. BMC Genomics 2010). We aim to down-regulate pheromone gland specific Fatty Acyl Reductase (FAR) and the Pheromone Biosynthesis Activating Neuropeptide (PBAN) receptor in vivo and in vitro. more >>>

Collaborators: Heiko Vogel, Andrea Barthel

• Signal and response coevolution
  in the two well-defined sex pheromone races of the European corn borer,
  Ostrinia nubilalis

In 2007 the Ostrinia consortium was formed between the Entomology and Neuroethology Departments at MPICE, the Biology Dept. of Lund University and the Dept. of Plant Protection of the Swedish University of Agricultural Sciences in Alnarp. The aims are 1) to identify the genes involved in female pheromone production and male response, and 2) to understand the evolution of pheromone divergence between the two races of O. nubilalis. Through QTL analysis, mapping of candidate genes and functional analysis we recently identified the gene responsible for the strain-specific difference if female pheromone production (Lassance et al. 2010. Nature 466). Currently we are identifying the genomic locations of the male response, behaviorally (Karpati et al. BMC Evol. Biol. in press; Olsson et al. BMC Evol. Biol. in press).

Collaborators: Teun Dekker, Bill Hansson, Zsolt Karpati, Fotini Koutroumpa, Jean-Marc Lassance, Christer Löfstedt, Shannon Olsson

• Finding the genetic basis of intraspecific variation
  in the sex pheromone of Heliothis virescens (Hv) and H. subflexa (Hs)

In sampling Hv populations from North Carolina to the east coast of Mexico and Hs populations from North Carolina to the west coast of Mexico, we found significant intraspecific variation in the sex pheromone of both species (Groot et al. 2009. Evolution 63). Part of this variation is likely due to phenotypic plasticity (Groot et al. 2010. J. Evol. Biol. in press). Currently we are assessing the genetic basis of this variation.

Collaborators: Carlos Blanco, Fred Gould, Juan Lopez, Coby Schal, Antonio Teran-Vargas

• Comparison of interspecific QTL and intraspecific QTL
  of Heliothis virescens (Hv) and H. subflexa (Hs) sex pheromones

We assessed the genetic basis of interspecific variation in the sex pheromone components of Hv and Hs through 3 x 2 backcrosses (Sheck et al. 2006. J. Evol. Biol. 19; Groot et al. 2009. Insect Biochem. Mol. Biol. 39) and found 5 consistent QTL and 7 additional QTL when using backcross families with larger sample size. Currently we are comparing the interspecific QTL with the intraspecific QTL to assess what part of the variation shows a continuum, which may point to a signature of selection.

Collaborators: Fred Gould, Coby Schal

• Characterization of fatty acyl reductases in four heliothine moths

PhD project Åsa Hagström

There are specific genes involved in biosynthesis of pheromones, and changes in their expression and functionality could affect the production of the pheromone signal severely. For example, a change in the pheromone composition could lead to reproductive isolation, or to a scenario where only a small amount of males would respond. more >>>

Main supervisor: Christer Löfstedt

Collaborators: Astrid T. Groot