Behavioural variation among divergent European and North American farmed and wild Atlantic salmon (Salmo salar) populations

Distinct early life stage gene expression effects of hybridization among European and North American farmed and wild Atlantic salmon populations

“…Additionally, among the ecologically relevant comparisons, we found the largest gene transcript level differences between domesticated EO and NA farmed strains (RP: 223 DEPs), which is concordant with an earlier observation by Roberge et al (2006) on country‐specific (Norway‐Canada) changes in transcription profiles by the domestication of farmed strains. This finding, however, contrasts with our hypothesis that commonalities due to domestication selection between Farm.NA and Farm.EO would lead to reduced gene expression differences, as was observed previously in regards to behavioural differences (Islam et al, 2020). Given that the Farm.EO strain has already undergone 12–15 generations of domestication selection, and the Farm.NA strain 7–8 generations (Glover et al, 2017), we cannot simply rule out the possibility that differences in the form and number of generations of domestication selection also contributed to the global gene expression differences between Farm.EO and Farm.NA strains, especially when only a single generation of domestication selection may change hundreds of gene expression patterns (Christie et al, 2016).…”

“…EO than the Farm.NA strain, as hypothesized, which was not un- Additionally, among the ecologically relevant comparisons, we found the largest gene transcript level differences between domesticated EO and NA farmed strains (RP: 223 DEPs), which is concordant with an earlier observation by Roberge et al (2006) on country-specific (Norway-Canada) changes in transcription profiles by the domestication of farmed strains. This finding, however, contrasts with our hypothesis that commonalities due to domestication selection between Farm.NA and Farm.EO would lead to reduced gene expression differences, as was observed previously in regards to behavioural differences (Islam et al, 2020). Given that the Farm.…”

“…Given that the Farm.EO strain has already undergone 12–15 generations of domestication selection, and the Farm.NA strain 7–8 generations (Glover et al, 2017), we cannot simply rule out the possibility that differences in the form and number of generations of domestication selection also contributed to the global gene expression differences between Farm.EO and Farm.NA strains, especially when only a single generation of domestication selection may change hundreds of gene expression patterns (Christie et al, 2016). Moreover, the large expression differences between these two domesticated strains with presumably similar phenotypes (Islam et al, 2020, 2022) may be partly reflective of the genetic redundancy of traits (Yeaman, 2015).…”

“…However, to our knowledge, this is the first experiment that characterizes early life (i.e., whole‐body transcriptome of fry at the end of yolk sac absorption) gene expression effects of hybridization, while comparing population‐specific differences among NA and EO farmed, NF wild salmon with natural evidence of EO secondary contact ~10,000 years before present, and F 1 hybrid salmon. We hypothesized that: (i) due to a common multigeneration domestication effect (e.g., Islam et al, 2020, in revision), EO and NA farmed fish will exhibit similar gene expression patterns; (ii) due to geographic and ancestral relationships, global gene expression patterns of NF wild fish will be more similar to that of NA farmed than that of EO farmed fish; and (iii) F 1 hybrids will display altered gene expression relative to wild and farmed fish. Our main goal was to understand the potential consequences of hybridization of EO and NA farmed escapees on NF wild populations to better guide sustainable aquaculture practices and the maintenance of wild populations.…”

Reared to become wild-like: addressing behavioral and cognitive deficits in cultured aquatic animals destined for stocking into natural environments—a critical review

“…Maladaptive traits generated in captivity can be detected already in the first captive-reared generation (e.g., Araki et al 2008, Christie et al 2016, Fraser et al 2019. Animals undergoing domestication selection (Teletchea 2021), whether intentionally or inadvertently, obtain traits favorable for good performance in aquaculture environments, which are not necessarily traits beneficial in the natural environment (Araki et al 2008, Islam et al 2020, Solberg et al 2020. Selection on certain culturepromoted behavioral traits could also act on the animals without domestication playing a role.…”