scholarly journals Genetic architecture of age at maturity can generate divergent and disruptive harvest-induced evolution

2017 ◽  
Vol 372 (1712) ◽  
pp. 20160035 ◽  
Author(s):  
Anna Kuparinen ◽  
Jeffrey A. Hutchings
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Genetic Architecture ◽  
Life History Traits ◽  
Single Locus ◽  
Sexually Dimorphic ◽  
Age At Maturity ◽  
Sexually Dimorphic Expression ◽  
Strong Control ◽  
Dimorphic Expression

Life-history traits are generally assumed to be inherited quantitatively. Fishing that targets large, old individuals is expected to decrease age at maturity. In Atlantic salmon ( Salmo salar ), it has recently been discovered that sea age at maturity is under strong control by a single locus with sexually dimorphic expression of heterozygotes, which makes it less intuitive to predict how life histories respond to selective fishing. We explore evolutionary responses to fishing in Atlantic salmon, using eco-evolutionary simulations with two alternative scenarios for the genetic architecture of age at maturity: (i) control by multiple loci with additive effects and (ii) control by one locus with sexually dimorphic expression. We show that multi-locus control leads to unidirectional evolution towards earlier maturation, whereas single-locus control causes largely divergent and disruptive evolution of age at maturity without a clear phenotypic trend but a wide range of alternative evolutionary trajectories and greater trait variability within trajectories. Our results indicate that the range of evolutionary responses to selective fishing can be wider than previously thought and that a lack of phenotypic trend need not imply that evolution has not occurred. These findings underscore the role of genetic architecture of life-history traits in understanding how human-induced selection can shape target populations. This article is part of the themed issue ‘Human influences on evolution, and the ecological and societal consequences’.

scholarly journals Demographic Traits Variation in a Pyrenean Newt (Calotriton asper) among Lacustrine and Stream Populations

Diversity ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 471
Author(s):  
Sebastià Camarasa ◽  
Neus Oromi ◽  
Delfí Sanuy ◽  
Fèlix Amat
Keyword(s):  
Life History ◽  
Body Size ◽  
Age Structure ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Size Structure ◽  
Maximum Size ◽  
Sexually Dimorphic ◽  
Age At Maturity ◽  
Demographic Traits

Demographic traits were analyzed in the Pyrenean brook newt (Calotriton asper) to evaluate whether its variability responds to the adaptation to the different habitats. In this study, life history traits of Calotriton asper were studied in nine populations living in two different kinds of habitats in the Pyrenees mountains: lakes and streams. Skeletochronology was used to determine age structure and different traits such as age at maturity and longevity. Age structure was different between populations and sexes. The two lacustrine populations, with facultative pedomorphosis, attained their maturity earlier. Age at sexual maturity ranged from 4 to 9 years and in some populations was similar between sexes while in others, females matured at younger ages than males. Maximum longevity varied from 7 to 35 years among populations and was correlated with the age at sexual maturity. Body size differed among populations, was sexually dimorphic, and this disparity was not related to the kind of habitat. The maximum size was found in the lacustrine population but exhibited high variation between populations. The results obtained show a significant variability between sexes and populations, in age and body size structure of Calotriton asper that did not depend on the habitat.

scholarly journals Cis-regulatory differences in isoform expression associate with life history strategy variation in Atlantic salmon

2019 ◽  
Author(s):  
Jukka-Pekka Verta ◽  
Paul Vincent Debes ◽  
Nikolai Piavchenko ◽  
Annukka Ruokolainen ◽  
Outi Ovaskainen ◽  
...  
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Life Histories ◽  
Life History Traits ◽  
Life History Strategies ◽  
Life History Trait ◽  
Gene Transcript ◽  
Genome Wide Association Studies ◽  
Age At Maturity ◽  
Life History Variation

AbstractA major goal in biology is to understand how evolution shapes variation in individual life histories. Genome-wide association studies have been successful in uncovering genome regions linked with traits underlying life history variation in a range of species. However, lack of functional studies of the discovered genotype-phenotype associations severely restrains our understanding how alternative life history traits evolved and are mediated at the molecular level. Here, we report a cis-regulatory mechanism whereby expression of alternative isoforms of the transcription co-factor vestigial-like 3 (vgll3) associate with variation in a key life history trait, age at maturity, in Atlantic salmon (Salmo salar). Using a common-garden experiment, we first show that vgll3 genotype associates with puberty timing in one-year-old salmon males. By way of temporal sampling of vgll3 expression in ten tissues across the first year of salmon development, we identify a pubertal transition in vgll3 expression where maturation coincided with a 66% reduction in testicular vgll3 expression. The late maturation allele was not only associated with a tendency to delay puberty, but also with expression of a rare transcript isoform of vgll3 pre-puberty. By comparing absolute vgll3 mRNA copies in heterozygotes we show that the expression difference between the early and late maturity alleles is largely cis-regulatory. We propose a model whereby expression of a rare isoform from the late allele shifts the liability of its carriers towards delaying puberty. These results reveal how regulatory differences can be a central mechanism for the evolution of life history traits.Author summaryAlternative life history strategies are an important source of diversity within populations and promote the maintenance of adaptive capacity and population resilience. However, in many cases the molecular basis of different life history strategies remains elusive. Age at maturity is a key adaptive life history trait in Atlantic salmon and has a relatively simple genetic basis. Using salmon age at maturity as a model, we report a mechanism whereby different transcript isoforms of the key age at maturity gene, vestigial-like 3 (vgll3), associate with variation in the timing of male puberty. Our results show how gene regulatory differences in conjunction with variation in gene transcript structure can encode for complex alternative life histories.

scholarly journals Growth Hormone Pretranslationally Regulates the Sexually Dimorphic Expression of the Prolactin Receptor Gene in Rat Liver

1990 ◽  
Vol 4 (8) ◽  
pp. 1235-1239 ◽  
Author(s):  
John A. Robertson ◽  
Lars-Arne Haldosén ◽  
Timothy J. J. Wood ◽  
Maureen K. Steed ◽  
Jan-Åke Gustafsson
Keyword(s):  
Growth Hormone ◽  
Rat Liver ◽  
Receptor Gene ◽  
Prolactin Receptor ◽  
Sexually Dimorphic ◽  
Sexually Dimorphic Expression ◽  
Prolactin Receptor Gene ◽  
Dimorphic Expression

Neuropeptide signalling shapes feeding and reproductive behaviours in male C. elegans

2021 ◽  
Author(s):  
Matthew J Gadenne ◽  
Iris Hardege ◽  
Djordji Suleski ◽  
Paris Jaggers ◽  
Isabel Beets ◽  
...  
Keyword(s):  
Synaptic Connectivity ◽  
Male Mating ◽  
Sexually Dimorphic ◽  
C Elegans ◽  
Mating Efficiency ◽  
Sexually Dimorphic Expression ◽  
Pharyngeal Pumping ◽  
Insight Into ◽  
Feeding Behaviours ◽  
Dimorphic Expression

Sexual dimorphism occurs where different sexes of the same species display differences in characteristics not limited to reproduction. For the nematode Caenorhabditis elegans, in which the complete neuroanatomy has been solved for both hermaphrodites and males, sexually dimorphic features have been observed both in terms of the number of neurons and in synaptic connectivity. In addition, male behaviours, such as food-leaving to prioritise searching for mates, have been attributed to neuropeptides released from sex-shared or sex-specific neurons. In this study, we show that the lury-1 neuropeptide gene shows a sexually dimorphic expression pattern; being expressed in pharyngeal neurons in both sexes but displaying additional expression in tail neurons only in the male. We also show that lury-1 mutant animals show sex differences in feeding behaviours, with pharyngeal pumping elevated in hermaphrodites but reduced in males. LURY-1 also modulates male mating efficiency, influencing motor events during contact with a hermaphrodite. Our findings indicate sex-specific roles of this peptide in feeding and reproduction in C. elegans, providing further insight into neuromodulatory control of sexually dimorphic behaviours.

Sexually dimorphic expression of myosin heavy chains in the adult mouse masseter

2000 ◽  
Vol 89 (1) ◽  
pp. 251-258 ◽  
Author(s):  
Jane M. Eason ◽  
Gail A. Schwartz ◽  
Grace K. Pavlath ◽  
Arthur W. English
Keyword(s):  
Adult Mouse ◽  
Fiber Type ◽  
Masticatory Muscles ◽  
Sexually Dimorphic ◽  
Heavy Chains ◽  
Tissue Sections ◽  
Type Composition ◽  
Sexually Dimorphic Expression ◽  
Dimorphic Expression

Little is known regarding the role of androgenic hormones in the maintenance of myosin heavy chain (MHC) composition of rodent masticatory muscles. Because the masseter is the principal jaw closer in rodents, we felt it was important to characterize the influence of androgenic hormones on the MHC composition of the masseter. To determine the extent of sexual dimorphism in the phenotype of masseter muscle fibers of adult (10-mo-old) C57 mice, we stained tissue sections with antibodies specific to type IIa and IIb MHC isoforms. Females contain twice as many fibers containing the IIa MHC as males, and males contain twice as many fibers containing the IIb MHC as females. There is a modest amount of regionalization of MHC phenotypes in the mouse masseter. The rostral portions of the masseter are composed mostly of type IIa fibers, whereas the midsuperficial and caudal regions contain mostly type IIb fibers. Using immunoblots, we showed that castration results in an increase in the expression of type IIa MHC fibers in males. Ovariectomy has no effect on the fiber type composition in females. We conclude that testosterone plays a role in the maintenance of MHC expression in the adult male mouse masseter.

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