The ability to learn and form memory is universal among animal species. Long-term memory is only formed when an animal receives multiple learning experiences, but the number that is required is variable. In this study, we compared two closely-related species of parasitic wasps, Nasonia vitripennis and N. giraulti. These wasps lay their eggs in other insects, their hosts, and can learn odours that guide them towards suitable hosts.
Nasonia vitripennis forms long-term memory after a single learning experience, whereas N. giraulti required multiple experiences. We have studied the genetic basis of this difference by backcrossing genes from the slow learner N. giraulti into the genetic background of N. vitripennis. This approach allowed us to identify two genomic regions that are responsible for the difference in long-term memory.
Genetic basis of variation in memory formation
We also compared gene expression patterns in the brains of the two species after a learning experience, which allowed us to identify species-specific differences in gene expression. This study has increased our knowledge on the genetic basis of variation in memory formation and facilitates further studies. Considering that the genetic basis of memory formation is highly conserved, the results of this research are likely applicable to other animal species, including humans, as well.