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Kotrschal, Kurt; Staaden, Moira J. van; Huber, Robert

doi:10.1023/a:1008839605380

Cited by 302 publications

(95 citation statements)

References 103 publications

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“…If differences in predation behavior between hatchery-reared wild and transgenic genotypes mainly are the result of altered learning ability, differences in ecological effects of these two predator types may diminish over the course of time. Alternatively, differences in rearing conditions may affect gene expression (including the transgene) and development (37)(38)(39), resulting in structural changes that could have long-lasting effects on traits, such as feeding behavior (40). For example, transgenic coho salmon have structural alterations of their pituitary gland (where GH is produced in wild fish) relative to genotypically wild fish (41) in addition to cranial abnormalities (42,43), which might affect brain development with irreversible effect on behavior.…”

Section: Discussionmentioning

confidence: 99%

Gene–environment interactions influence ecological consequences of transgenic animals

Sundström

Lõhmus

Tymchuk

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Production of transgenic animals has raised concern regarding their potential ecological impact should they escape or be released to the natural environment. This concern has arisen mainly from research on laboratory-reared animals and theoretical modeling exercises. In this study, we used biocontained naturalized stream environments and conventional hatchery environments to show that differences in phenotype between transgenic and wild genotypes depend on rearing conditions and, critically, that such genotype-by-environment interactions may influence subsequent ecological effects in nature. Genetically wild and growth hormone transgenic coho salmon (Oncorhynchus kisutch) were reared from the fry stage under either standard hatchery conditions or under naturalized stream conditions. When reared under standard hatchery conditions, the transgenic fish grew almost three times longer than wild conspecifics and had (under simulated natural conditions) stronger predation effects on prey than wild genotypes (even after compensation for size differences). In contrast, when fish were reared under naturalized stream conditions, transgenic fish were only 20% longer than the wild fish, and the magnitude of difference in relative predation effects was much reduced. These data show that genotype-by-environment interactions can influence the relative phenotype of transgenic and wild-type organisms and that extrapolations of ecological consequences from phenotypes developed in the unnatural laboratory environment may lead to an overestimation or underestimation of ecological risk. Thus, for transgenic organisms that may not be released to nature, the establishment of a range of highly naturalized environments will be critical for acquiring reliable experimental data to be used in risk assessments.coho salmon ͉ phenotypic plasticity ͉ risk-assessment

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Section: Discussionmentioning

confidence: 99%

Gene–environment interactions influence ecological consequences of transgenic animals

Sundström

Lõhmus

Tymchuk

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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“…Larger brains usually show larger information-specific processing units, implying increased sensory resolution [31,57,58]. From an evolutionary point of view, such increased resolution would probably result in benefits (e.g.…”

Section: Relationship Between Cognitive Abilities Brain Size and Metmentioning

confidence: 99%

Costs of memory: lessons from ‘mini’ brains

2010

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Variation in learning and memory abilities among closely related species, or even among populations of the same species, has opened research into the relationship between cognition, ecological context and the fitness costs, and benefits of learning and memory. Such research programmes have long been dominated by vertebrate studies and by the assumption of a relationship between cognitive abilities, brain size and metabolic costs. Research on these 'large brained' organisms has provided important insights into the understanding of cognitive functions and their adaptive value. In the present review, we discuss some aspects of the fitness costs of learning and memory by focusing on 'mini-brain' studies. Research on learning and memory in insects has challenged some traditional positions and is pushing the boundaries of our understanding of the evolution of learning and memory.

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“…Most studies have focussed on functional implications of brain size and the development of major brain regions in vertebrates, examining ecological or behavioural correlates with brain organisation (Barton et al 1995;Kotrschal et al 1998;Lefebvre et al 2002;Yopak et al 2007;Shumway 2008), whereas few have examined any potential physiological mechanisms that drive this diversity (Elliot and Crespi 2008). Much of neural development occurs during gestation and brain tissue accounts for a disproportionate amount of metabolic costs in early life (Martin 1996;Elliot and Crespi 2008), raising questions about the role of reproductive diversity, and the level of maternal investment in the evolution of relative brain sizes.…”

Section: Introductionmentioning

confidence: 99%

“…Relative brain size and the relative development of major brain areas have been correlated with ecology (i.e. habitat type, feeding mode), and these patterns do not necessarily follow phylogenetic groupings (Yopak et al 2007;Lisney et al 2008;Yopak and Montgomery 2008;Yopak and Frank 2009), similar to patterns seen in other vertebrates, such as teleosts, birds and mammals (Huber et al 1997;Kotrschal et al 1998;de Winter and Oxnard 2001). There is some evidence that reproductive mode may be correlated with variation in brain size and organisation; the sharks with placental viviparity, such as the Carcharhinidae and Sphyrnidae, have among the largest relative brain sizes within chondrichthyans (Yopak et al 2007), although this has not as yet been statistically tested.…”

Section: Introductionmentioning

confidence: 99%

Does more maternal investment mean a larger brain? Evolutionary relationships between reproductive mode and brain size in chondrichthyans

Mull

Yopak

Dulvy

2011

Mar. Freshwater Res.

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Abstract. Chondrichthyans have the most diverse array of reproductive strategies of any vertebrate group, ranging from egg-laying to live-bearing with placental matrotrophy. Matrotrophy is defined as additional maternal provisioning beyond the yolk to the developing neonate; in chondrichthyans, this occurs through a range of mechanisms including uterine milk, oophagy, uterine cannibalism and placentotrophy. Chondrichthyans also exhibit a wide range of relative brain sizes and highly diverse patterns of brain organisation. Brains are energetically expensive to produce and maintain, and represent a major energetic constraint during early life in vertebrates. In mammals, more direct maternal-fetal placental connections have been associated with larger brains (steeper brain-body allometric scaling relationships). We test for a relationship between reproductive mode and relative brain size across 85 species from six major orders of chondrichthyans by using several phylogenetic comparative analyses. Ordinary least-squares (OLS) and reduced major axis (RMA) regression of body mass versus brain mass suggest that increased maternal investment results in a larger relative brain size. Our findings were supported by phylogenetic generalised least-squares models (pGLS), which also highlighted that these results vary with evolutionary tempo, as described by different branch-length assumptions. Across all analyses, maximum body size had a significant influence on the relative brain size, with large-bodied species (body mass .100 kg) having relatively smaller brains. The present study suggests that there may be a link between reproductive investment and relative brain size in chondrichthyans; however, a more definitive test requires a better-resolved phylogeny and a more nuanced categorisation of the level of maternal investment in chondrichthyans.

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Untitled

Cited by 302 publications

References 103 publications

Gene–environment interactions influence ecological consequences of transgenic animals

Gene–environment interactions influence ecological consequences of transgenic animals

Costs of memory: lessons from ‘mini’ brains

Does more maternal investment mean a larger brain? Evolutionary relationships between reproductive mode and brain size in chondrichthyans

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