scholarly journals Life history genomic regions explain differences in Atlantic salmon marine diet specialization

2019 ◽  
Author(s):  
Tutku Aykanat ◽  
Martin Rasmussen ◽  
Mikhail Ozerov ◽  
Eero Niemelä ◽  
Lars Paulin ◽  
...  

AbstractAnimals employ various foraging strategies along their ontogeny to acquire energy, and with varying degree of efficiencies, to support growth, maturation and subsequent reproduction events. Individuals that can efficiently acquire energy early are more likely to mature at an earlier age, as a result of faster energy gain which can fuel maturation and reproduction.We aimed to test the hypothesis that heritable resource acquisition variation that co-varies with efficiency along the ontogeny would influence maturation timing of individuals.To test this hypothesis, we utilized Atlantic salmon as a model which exhibit a simple, hence trackable, genetic control of maturation age. We then monitored the variation in diet acquisition (quantified as the stomach fullness and composition) of individuals with different ages, and linked it genomic regions (haploblocks) that were previously identified to be associated with age-at-maturity.Consistent with the hypothesis, we demonstrated that one of the life history genomic regions tested (six6) was indeed associated with age-dependent differences in stomach fullness. Prey composition was marginally linked to both genomic regions (six6 and vgll3). We further showed Atlantic salmon switched to the so-called “feast and famine” strategy along the ontogeny, where older age groups exhibited heavier stomach content, but that came at the expense of running on empty more often.These results suggest genetic variation underlying resource utilization variation may explain the genetic basis of age structure in Atlantic salmon. Given that ontogenetic diet has a genetic component and the strong spatial diversity associated with these genomic regions, we predict populations with diverse maturation age will have diverse evolutionary responses to future changes in marine food-web structures.

2018 ◽  
Author(s):  
Tutku Aykanat ◽  
Mikhail Ozerov ◽  
Juha-Pekka Vähä ◽  
Panu Orell ◽  
Eero Niemelä ◽  
...  

AbstractGenetic correlations in life history traits may result in unpredictable evolutionary trajectories if not accounted for in life-history models. Iteroparity (the reproductive strategy of reproducing more than once) in Atlantic salmon (Salmo salar) is a fitness trait with substantial variation within and among populations. In the Teno River in northern Europe, iteroparous individuals constitute an important component of many populations and have experienced a sharp increase in abundance in the last 20 years, partly overlapping with a general decrease in age structure. The physiological basis of iteroparity bears similarities to that of age at first maturity, another life history trait with substantial fitness effects in salmon. Sea age at maturity in Atlantic salmon is controlled by a major locus around the vgll3 gene, and we used this opportunity demonstrate that the two traits are genetically correlated around this genome region. The odds ratio of survival until second reproduction was up to 2.4 (1.8-3.5 90% CI) times higher for fish with the early-maturing vgll3 genotype (EE) compared to fish with the late-maturing genotype (LL). The association had a dominance architecture, although the dominant allele was reversed in the late-maturing group compared to younger groups that stayed only one year at sea before maturation. Post hoc analysis indicated that iteroparous fish with the EE genotype had accelerated growth prior to first reproduction compared to first-time spawners, across all age groups, while this effect was not detected in fish with the LL genotype. These results broaden the functional link around the vgll3 genome region and help us understand constraints in the evolution of life history variation in salmon. Our results further highlight the need to account for genetic correlations between fitness traits when predicting demographic changes in changing environments.


2021 ◽  
Author(s):  
Jenni M. Prokkola ◽  
Eirik R Åsheim ◽  
Sergey Morozov ◽  
Paul Bangura ◽  
Jaakko Erkinaro ◽  
...  

1. The physiological underpinnings of life history adaptations in ectotherms are not well understood. Theories suggest energy metabolism influences life history variation via modulation of resource acquisition. However, the genetic basis of this relation and its dependence on ecological conditions, such as food availability, have rarely been characterized, despite being critical to predicting the responses of populations to environmental changes. 2. The Atlantic salmon (Salmo salar) is an emerging wild model species for addressing these questions; strong genetic determination of age-at-maturity at two unlinked genomic regions (vgll3 and six6) enables the use of complex experimental designs and tests of hypotheses on the physiological and genetic basis of life-history trait variation. 3. In this study, we crossed salmon to obtain individuals with all combinations of late and early maturation genotypes for vgll3 and six6 within full-sib families. Using more than 250 juveniles in common garden conditions, we tested (i) whether metabolic phenotypes (i.e., standard and maximum metabolic rates, and absolute aerobic scope) were correlated with the age-at-maturity genotypes and (ii) if high vs. low food availability modulated the relationship. 4. We found that salmon with vgll3 early maturation genotype had a higher aerobic scope and maximum metabolic rate, but not standard metabolic rate, compared to salmon with vgll3 late maturation genotype. This suggests that physiological or structural pathways regulating maximum oxygen supply or demand are potentially important for the determination of age-at-maturity in Atlantic salmon. 5. Vgll3 and six6 exhibited physiological epistasis, whereby maximum metabolic rate significantly decreased when late maturation genotypes were present concurrently in both loci compared to other genotype combinations. 6. The growth of the feed restricted group decreased substantially compared to the high food group. However, the effects of life-history genomic regions were similar in both feeding regimes, indicating a lack of genotype-by-environment interactions. 7. Our results indicate that aerobic performance of juvenile salmon may affect their age-at-maturity. The results may help to better understand the mechanistic basis of life-history variation, and the metabolic constrains on life-history evolution.


2020 ◽  
Vol 89 (11) ◽  
pp. 2677-2691 ◽  
Author(s):  
Tutku Aykanat ◽  
Martin Rasmussen ◽  
Mikhail Ozerov ◽  
Eero Niemelä ◽  
Lars Paulin ◽  
...  

Author(s):  
Paul W Turke

Abstract The severity of COVID-19 is age-related, with the advantage going to younger age groups. Five reasons are presented. The first two are well-known, are being actively researched by the broader medical community, and therefore are discussed only briefly here. The third, fourth, and fifth reasons derive from evolutionary life history theory, and potentially fill gaps in current understanding of why and how young and old age groups respond differently to infection with SARS-CoV-2. Age of onset of generalized somatic aging, and the timing of its progression, are identified as important causes of these disparities, as are specific antagonistic pleiotropic tradeoffs in immune system function.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pablo Cáceres ◽  
Agustín Barría ◽  
Kris A. Christensen ◽  
Liane N. Bassini ◽  
Katharina Correa ◽  
...  

AbstractSea lice (Caligus rogercresseyi) is an ectoparasite which causes major production losses in the salmon aquaculture industry worldwide. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two of the most susceptible salmonid species to sea lice infestation. The objectives of this study were to: (1) identify genomic regions associated with resistance to Caligus rogercresseyi in Atlantic salmon and rainbow trout by performing single-step Genome-Wide Association studies (ssGWAS), and (2) identify candidate genes related to trait variation based on exploring orthologous genes within the associated regions across species. A total of 2626 Atlantic salmon and 2643 rainbow trout were challenged and genotyped with 50 K and 57 K SNP panels, respectively. We ran two independent ssGWAS for sea lice resistance on each species and identified 7 and 13 regions explaining more than 1% of the genetic variance for the trait, with the most important regions explaining 3% and 2.7% for Atlantic salmon and rainbow trout, respectively. We identified genes associated with immune response, cytoskeleton function, and cell migration when focusing on important genomic regions for each species. Moreover, we found 15 common orthogroups which were present in more than one associated genomic region, within- or between-species; however, only one orthogroup showed a clear potential biological relevance in the response against sea lice. For instance, dual-specificity protein phosphatase 10-like (dusp10) and dual-specificity protein phosphatase 8 (dusp8) were found in genomic regions associated with lice density in Atlantic salmon and rainbow trout, respectively. Dusp10 and dusp8 are modulators of the MAPK pathway and might be involved in the differences of the inflammation response between lice resistant and susceptible fish from both species. Our results provide further knowledge on candidate genes related to sea lice resistance and may help establish better control for sea lice in fish populations.


Author(s):  
Gaotian Zhang ◽  
Jake D Mostad ◽  
Erik C Andersen

Abstract Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g. a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. Additionally, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.


1979 ◽  
Vol 36 (11) ◽  
pp. 1408-1412 ◽  
Author(s):  
A. J. Sosiak ◽  
R. G. Randall ◽  
J. A. McKenzie

Hatchery-reared Atlantic salmon (Salmo salar) parr were captured 1–3 mo after release in streams, along with wild parr from the same streams. Identification of their stomach contents showed total number of organisms and number of taxa per stomach were greater and there was a higher index of stomach fullness in wild than in hatchery parr resident ≤ 2 mo in a stream. Wild parr consumed more Brachycentridae, Hydroptilidae, Diptera, and Plecoptera than did hatchery parr, but sometimes less Odontoceridae and Heptageniidae. These differences may have arisen from size-dependent food selection, the effects of feeding experience, or possible microhabitat differences between wild and hatchery parr. Key words: salmon parr, hatchery-reared, wild, feeding


1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.


2011 ◽  
Vol 26 (S2) ◽  
pp. 1887-1887
Author(s):  
T. Butkova ◽  
N. Kibrik

ObjectiveFamily-sexual disharmonies - are the frequent reasons of suicide behaviour. Design: Complex inspection of 62 patients, in the age from 18 years has been performed. In the anamnesis patients had suicide behaviour owing to family-sexual disharmonies.Results1.Age when suicide attempts have been accomplished. Middle age has made 31 ± 8,8 years; 20–29 years - 43% (27 person); 30-39 years - 39% (24 person). The other 11 person-were included into the age groups of 40–49, 50–59 years.2.The reasons of autoaggressive behaviour: Suicide attempts owing to divorce, ideas of matrimonial incorrectness - 52% (32 person).Owing to the unfair attitude from the nearest environment or a dissatisfaction with behaviour and personal qualities of significant another - 48% (30 person). Age features: For young age - unavailability of young spouses to home life, absence of tolerance and respect to each other. Average age group - a dissatisfaction with behaviour of the partner. The senior age group - somatic diseases, loneliness, loss of relatives 3. In 66% of cases (41 person) suicide had no in the anamnesis of mental diseases at relatives.ConclusionsThe primary goal at rendering the psychotherapeutic help - revealing and correction of non adaptive installations of the person. Formation of confidential and empathic attitudes in family. It has been confirmed correlation analysis between partners′ satisfaction attitudes, personal characteristics suicident. It is necessary to raise availability of the information on various aspects of sexual health, psychohygiene of intimate relations.


2017 ◽  
Vol 1 (5) ◽  
Author(s):  
Geir H. Bolstad ◽  
Kjetil Hindar ◽  
Grethe Robertsen ◽  
Bror Jonsson ◽  
Harald Sægrov ◽  
...  

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