Plasticity in gene transcription explains the differential performance of two invasive fish species

Phenotypic plasticity buffers organisms from environmental change and is hypothesized to aid the initial establishment of non-indigenous species in novel environments and post-establishment range expansion. The genetic mechanisms that underpin phenotypically plastic traits are generally poorly characterized; however, there is strong evidence that modulation of gene transcription is an important component of these responses. Here we use RNA sequencing to examine the transcriptional basis of temperature tolerance for round and tubenose goby, two non-indigenous fish species that differ dramatically in the extent of their Great Lakes invasions despite similar invasion dates. We used generalized linear models of read count data to compare gene transcription responses of organisms exposed to increased and decreased water temperature from those at ambient conditions. We identify greater response in the magnitude of transcriptional changes for the more successful round goby compared with the le...