The role of epigenetic mechanisms in understanding invasion success of a non-native species: investigation of inter-population differences in phenotypic plasticity along an invasion succession

Ali Serhan Tarkan

The aim of this project, in order to understand invasive success of a non-native species, is to determine the phenotypic differences of populations of the invading species along an invasion succession and find the gene profile stimulating these differences. The proposed project will have two components. First, important biological and ecological features (growth, reproduction, life history traits, food and habitat interactions with other species) of the selected model species (i.e. Lepomis gibbosus) will be elucidated from the populations at different phases of the invasion in a large basin and differences or similarities to be found will be interpreted with the aid of molecular tools at the genetic basis.

Biological invasions are natural phenomenon occurred at very long time periods however in case of physical and chemical barriers are removed by especially human interference, transfer of the species beyond their natural ranges is facilitated and accelerated. There are many important processes in the invasion succession of a species, which account for various ecological and evolutionary dynamics including three invasion phases (i.e., introduction, establishment and spread). In this perspective, to describe heritable biological characters forming invasions is crucial to predict present and future distribution patterns of the non-native species, habitats prone to invasion, impact to ecosystems and eventually expected invasion routes. Understanding reasons underlying a successful invasion depends on revealing adaptive features of invasive species and this is only possible by elucidating bio-ecological properties of the species and related genetic mechanism. More specifically, recent studies clearly indicated that adaptive responses of invasive species are results of complicated interactions between evolutionary processes and phenotypic plasticity however in most cases these responses are interpreted based on only the differences among the populations without testing underlying genetic variations in evolutionary adaptation. Establishing a self-sustaining population of any non-native species is only possible when they could produce sufficient number of surviving offsprings that are capable of creating phenotypic adaptations to their new environments. Within this concept, a new approach is presented in the proposed project for the world and all invasion-related characters of a non-native species are aimed to work along an invasion gradient in a big basin to find invasion success and rate of an invasive species. This project is expected to clearly present adaptation and colonization processes to marginal and new habitats by investigating all invasion phases of non-native species.

This will be done by studying phenotypic variations and their genotypic bases at each invasion phase. The fish specimens of the model species (Lepomis gibbosus) and other co-occurring native species caught by monthly samplings will be studied with state-of-the-art methods for their growth (ageing, relative and ultimate growth, condition), reproduction (size at maturity, fecundity, reproduction effort), feeding ecology (trophic level) and habitat interactions as well as gene expression profiles describing the phenotypic variations to be found.

As the molecular method, which will be used in the proposed project is able to show the underlying genetic profile of impact and invasion success of non-native/invasive species, the outcomes analysed by optimized protocols, species/gene-specific primers and expression profiles are expected to serve as reference source. The outcomes of the project are expected to fill a big gap in control and management of non-native species in Turkey. These outcomes will also be used to establish national and international collaborations with related institutions. The findings will prevent severe economic loses before an invasive species become established by providing critical information on distribution and invasion success at each level of invasion. In this regard, governmental institutions will be informed and likely negative impacts will be minimized.

Scientific and Technological Research Council Of Turkey (TUBİTAK)